Academic literature on the topic 'Physico-Mechanical and hygro-Thermal properties'
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Journal articles on the topic "Physico-Mechanical and hygro-Thermal properties":
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Cao, Rulong, Juhani Marttila, Veikko Möttönen, Henrik Heräjärvi, Pekka Ritvanen, and Erkki Verkasalo. "Mechanical properties and water resistance of Vietnamese acacia and rubberwood after thermo-hygro-mechanical modification." European Journal of Wood and Wood Products 78, no. 5 (June 18, 2020): 841–48. http://dx.doi.org/10.1007/s00107-020-01552-7.
Abstract:
Abstract Low density and poor mechanical performance often limit utilisation of sawn wood from fast-growing plantation forests. Thermo-hygro-mechanical modification (THM) of timber is one innovation for improving the properties of light-weight wood species. The objective of this study was to determine the effects of THM and subsequent thermal treatment on dry density, modulus of elasticity (MOE), compression strength, Brinell hardness, and swelling behaviour in immersion tests on two fast-growing Vietnamese species, acacia (Acacia mangium) and rubberwood (Hevea brasiliensis). Test boards were modified in an industrial kiln, in which a tangential thickness compression of 14% and 12% were aimed for acacia and rubberwood, respectively, either with or without subsequent thermal treatment at 210 °C. Dry density, MOE, Brinell hardness, compression strength, and dimensional changes in water immersion tests of specimens were measured from the modified and unmodified reference materials, the latter ones being kiln dried at 50 °C. The results showed that the responses of the mechanical properties were more evident for rubberwood than for acacia. In rubberwood, the MOE and compression strength of wood thermo-hygro-mechanically modified with or without thermal treatment were higher than those of kiln-dried reference specimens throughout the thickness profile. In case of acacia, similar differences between the modified and reference specimens were observed only in the surface layer. Density and Brinell hardness of thermo-hygro-mechanically modified rubberwood were higher than those of reference specimens, but after thermal treatment they did not differ from (acacia) or were lower (rubberwood) than those of THM specimens. Post-compression thermal treatment increased the hydrophobicity of THM specimens.
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Nshimiyimana, Philbert, Adamah Messan, and Luc Courard. "Physico-Mechanical and Hygro-Thermal Properties of Compressed Earth Blocks Stabilized with Industrial and Agro By-Product Binders." Materials 13, no. 17 (August 26, 2020): 3769. http://dx.doi.org/10.3390/ma13173769.
Abstract:
This study investigated the engineering properties of compressed earth blocks (CEBs) stabilized with by-product binders: calcium carbide residue (CCR) and rice husk ash (RHA). The dry mixtures were prepared using the earthen material and 0–25 wt% CCR, firstly, and 20 wt% CCR partially substituted by the RHA (CCR:RHA in 20:0–12:8 ratios), secondly. The appropriate amount of water was thoroughly mixed with the dry mixtures. The moistened mixtures were manually compressed into CEBs, cured, dried, and tested. The stabilization of CEBs with CCR increased the dry compressive strength (CS) from 1.1 MPa with 0% CCR to 4.3 MPa with 10% CCR and above; decreased the bulk density (ρb: 1800–1475 kg/m3) and increased the total porosity (TP:35–45%). This resulted in the improvement of the coefficient of structural efficiency (CSE: 610–3050 Pa∙m3/kg). It also improved the thermal efficiency given the decrease of the thermal conductivity (λ: 1.02–0.69 W/m∙K), thermal diffusivity (a: 6.3 × 10−7 to 4.7 × 10−7 m2/s) and thermal penetration depth (δp: 0.13–0.11 m). The RHA further improved the CS up to 7 MPa, reaching the optimum with 16:4 CCR:RHA (ρb: 1575 kg/m3 and TP: 40%). The latter reached higher CSE (4460 Pa∙m3/kg) than cement stabilized CEBs (3540 Pa∙m3/kg). It reached lower λ (0.64 w/m∙K), a (4.1 × 10−7 m2/s) and δp (0.11 m) than cement CEBs (1.01 w/m∙K, 6.8 × 10−7 m2/s, and 0.14 m). Additionally, the stabilization of CEBs with by-products improved the moisture sorption capacity. The improvement of the structural and thermal efficiency of CEBs by the stabilization with by-product binders is beneficial for load-bearing capacity and thermal performances in multi-storey buildings.
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Hsu, Hsiang Chen, Li Ming Chu, Lih Shan Chen, and Shen Li Fu. "Comprehensive Hygro-Thermo-Vapor Pressure Model for CMOS Image Sensor." Key Engineering Materials 419-420 (October 2009): 493–96. http://dx.doi.org/10.4028/www.scientific.net/kem.419-420.493.
Abstract:
A combined effect of moisture diffusion, heat transfer, and hygro-thermo-vapor pressure modeling for pre-mold QFN CMOS Image Sensor (CIS) package has been developed in this study. Hygroscopic swelling properties such as saturation, coefficient of moisture expansion (CME) and activation energy can be extracted through TMA (Thermal Mechanical Analysis) and TGA (Thermal Gravitational Analysis) instruments. Fick’s second law of transient diffusion is solved by using finite element analysis (FEA) to evaluate the overall moisture distributions. With obtained experimental data, a three-dimensional FEA CIS model using the “thermal-wetness” technique is developed to predict the moisture absorption, moisture desorption, temperature distributions, hygro-thermo-vapor pressure mechanical coupled effect and the residual stress distributions at JEDEC pre-conditioning standard JESD22-A120.
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Dong, Wanguo, Chunlin Liu, Xueben Bao, Tengfei Xiang, and Depeng Chen. "Advances in the Deformation and Failure of Concrete Pavement under Coupling Action of Moisture, Temperature, and Wheel Load." Materials 13, no. 23 (December 4, 2020): 5530. http://dx.doi.org/10.3390/ma13235530.
Abstract:
The deformation and cracking of concrete will lead to various deterioration processes, which will greatly reduce the durability and service life of the concrete pavement. The relating previous studies and analysis revealed that the coupling action of environmental temperature, moisture, and wheel load will cause cracking and seriously affect the normal service and durability of pavement concrete. This paper presents theoretical and numerical state-of-the-art information in the field of deformation and failure of pavement concrete under coupling action of moisture, temperature, and wheel load and draws some conclusions. (a) Concrete is a typical porous material, moisture and heat transfer theory has obtained enough data to simulate the hygro-thermo properties of concrete, and the relationship between moisture and heat is very clear. (b) There are few studies on concrete pavement or airport pavement considering the coupling action of moisture, temperature, and wheel load. (c) Concrete pavement is subjected to hygro-thermal-mechanical coupling action in service, which has the characteristics of a similar period and its possible fatigue effect. (d) COMSOL software has certain advantages for solving the coupled hygro-thermal-mechanical of concrete.
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OUEDRAOGO, Adelaïde Lareba, Adamah MESSAN, Etienne MALBILA, Emmanuel OUEDRAOGO, Dieudonné Joseph BATHIEBO, Florent pèlèga KIENO, and Philippe BLANCHART. "Thermo-Physical, Mechanical and Hygro-Thermal Properties of Newly Produced Aerated Concrete." Journal of Materials Science and Surface Engineering 8, no. 2 (2021): 1021–28. http://dx.doi.org/10.52687/2348-8956/823.
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Pedergnana, Matthieu, and Soofia Tahira Elias Ozkan. "Hygro-Thermal, Hydric, and Mechanical Properties of Fibre and Aggregate-Reinforced Earth Plasters." International Journal of Digital Innovation in the Built Environment 10, no. 2 (July 2021): 29–45. http://dx.doi.org/10.4018/ijdibe.2021070103.
Abstract:
Earth plasters have been used as a protective coating for buildings but, due to their low strength and low resistance to weather conditions, they have been abandoned for more resistant materials which in return lack vapour permeability. Earth plasters have usually a high moisture sorption rate, and their water vapour permeability is high, allowing the transfer of humidity through the material. These properties make them an interesting material for controlling vapour movement in humid rooms. Improving their strength can be done by adding aggregates and/or fibres, but the real impact of using one type or another of fibres or aggregate is unknown. This research aims to understand the consequence of the choice of fibre or sand in the improvement of strength of plasters and the conservation of the plaster hygro-thermal properties. Properties of plasters using alternative fibres or aggregates such as wool, cow hair, pine needles, sand aimed for concrete mixes, or not properly graded sand have been compared to plasters made more traditionally with chaff fibres and mason sand.
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Adam, Laurentiu, and Dorina-Nicolina ISOPESCU. "PHYSICO-MECHANICAL PROPERTIES INVESTIGATION OF HEMPCRETE." Journal of Applied Life Sciences and Environment 55, no. 1(189) (2022): 75–84. http://dx.doi.org/10.46909/alse-551047.
Abstract:
Food, energy and construction are the three main domains in which different uses of industrial hemp confirm the role and importance that agriculture has in human life. In the current context with an increased need for energy efficiency and environmental protection, the attention of scientists is directed towards the identification of ecological construction materials, and a sustainable way of life, where the circular economy must become part of people’s living habits. The objective of the research was to analyze the thermo-mechanical properties of hempcrete. The goal is to determine a point of reference for future studies that will aim to adapt the agreed compositions to the particularities of the raw material obtained locally. Measurements were determined through laboratory tests, performed on specimens obtained using, for the base material, the woody part of industrial hemp, and for the binder, a mixture consisting of hydrated lime and Portland cement. The results place the construction materials made from hemp vegetable waste in the group of heat-insulating products characterized by low specific weight and thermal transfer coefficients, according with conventional insulating materials, with values between those of polyurethane foam and autoclaved cellular concrete.
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Yu, Peiyang, Peng-Zhi Pan, Guangliang Feng, Zhenhua Wu, and Shankun Zhao. "Physico-mechanical properties of granite after cyclic thermal shock." Journal of Rock Mechanics and Geotechnical Engineering 12, no. 4 (August 2020): 693–706. http://dx.doi.org/10.1016/j.jrmge.2020.03.001.
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Yaşar, E., Y. Erdoğan, and H. Güneyli. "Determination of the thermal conductivity from physico-mechanical properties." Bulletin of Engineering Geology and the Environment 67, no. 2 (February 16, 2008): 219–25. http://dx.doi.org/10.1007/s10064-008-0126-5.
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Turgut, Paki, Mehmet Irfan Yesilnacar, and Husamettin Bulut. "Physico-thermal and mechanical properties of Sanliurfa limestone, Turkey." Bulletin of Engineering Geology and the Environment 67, no. 4 (March 26, 2008): 485–90. http://dx.doi.org/10.1007/s10064-008-0145-2.
Dissertations / Theses on the topic "Physico-Mechanical and hygro-Thermal properties":
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Se, Golpayegani Motamedi Aida. "Caractérisation du bois de Mûrier blanc (Morus alba L.) en référence à son utilisation dans les luths Iraniens." Thesis, Montpellier 2, 2011. http://www.theses.fr/2011MON20157.
Abstract:
L'objectif est de mieux connaître les diverses propriétés (physico-mécaniques, biologiques et chimiques) du bois de Mûrier blanc (Morus alba L.), en tant que matériau éminemment utilisé dans la fabrication de luths Iraniens. La différence de caractéristiques vibratoires de cette espèce a été mesurée en fonction de la présence d'extractibles, mais aussi pour trois traitements artisanaux qui ont été adaptés à l'échelle du laboratoire.Le bois Mûrier blanc est caractérisé par un module spécifique modéré, un amortissement plus bas que prévu et une anisotropie faible entre ses trois axes. Il est précisé que cette espèce ne peut pas être classifiée avec les mêmes normes que les autres bois utilisés pour les instruments classiques Européens. En utilisant les deux extractions indépendantes et successives, il est révélé que l'amortissement est régi par deux types d'extraits, certains l'abaissent et certains l'augmentent. Ces composés ne sont pas tous extractibles par les mêmes solvants. L'immersion de longue durée dans une eau à température ambiante ne modifie pas les propriétés mécaniques de l'espèce, toutefois, elle peut laisser le bois avec des défauts irréversibles. Un court traitement à l'eau chaude (70°C) entraîne l'augmentation de l'amortissement et la diminution du module spécifique. Dans ce dernier cas, des modifications sont presque progressives avec le temps.Le bois de Mûrier blanc semble être « très durable » par rapport à une attaque fongique, même dans des conditions extrêmes. Le délavage dans l'eau n'a pas d'effets sur la résistance de cette espèce contre basidiomycètes. Ce bois est classé « moyennement durable » contre l'attaque des termites et devient sensible après le délavage. Ses extractibles ont donc des effets toxique sur les termites. Les phénols, acides gras, stérols, hydrocarbures supérieurs, et composés aromatiques sont les composés présents dans les extraits de cette espèce. Le résorcinol, composé prédominant trouvé dans l'espèce, a été récemment rapporté comme la cause de plusieurs problèmes de santé, ce qui est aujourd'hui observé chez les artisans IraniensThis work aims at studying the several divers properties (Physico-mechanical, biological and chemical) of white Mulberry (Morus alba L.), as the leading material used in fabrication of Iranian lutes. The vibrational characteristic of this species is measured in relation with secondary metabolites (extractives) as well as three artisanal hygro-thermal treatments adapted to laboratory scale.White Mulberry wood is characterized with a moderate specific modulus, less than expected damping and a low anisotropy between three directions. It is specified that this species cannot be described with the same standards as other woods used in European classical instruments. Using independent and successive extractions reveal that two types of extraneous compounds govern the damping in this wood, some raising it, when the rest have a decreasing effect. These compounds are not all extractable by the same solvents.Long time immersion in water at ambient temperature hardly changes mechanical properties of the species, however, it can leave wood with irreversible defects. Hot water treatment at 70°C results for damping and moduli to be increased and decreased respectively. These changes are time related. Several mild desorption and adsorption cycles, seem to reduce damping without greatly endangering the moduli. White Mulberry wood is found to be very durable towards fungi, even in extreme conditions. Water leaching seems to be affectless on this species resistance towards basidiomycetes. This wood is rated moderately durable towards termites and becomes sensible after water leaching. Extractives seem to play important role in this wood natural resistance, as they are found to have toxic effect on termites. Resorcinol, a phenol, is the leading compound in the extractives of white Mulberry. Fatty acids, sterols, higher hydrocarbons, and aromatic compounds are also found as the constituents of secondary metabolites. Resorcinol is documented to cause irritations close to what is normally experienced by the fabricants working with white Mulberry for a long time
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Daher, Suzanne. "Optimisation de la formulation d'un béton de chanvre : effet des interactions physico-chimiques entre les particules végétales et le liant." Electronic Thesis or Diss., Amiens, 2022. http://www.theses.fr/2022AMIE0041.
Abstract:
Le béton de chanvre est l'un des matériaux de construction biosourcés le plus en vogue en France. Il est souvent utilisé comme matériau de remplissage et/ou d'isolation, dans un système éco-constructif. Compte tenu de sa forte porosité, ce béton présente des performances thermiques et hygriques particulièrement intéressantes. Toutefois, alors que son niveau d'isolation thermique s'améliore lorsqu'on diminue sa densité, ce béton de chanvre voit parallèlement ses propriétés mécaniques diminuer. C'est la raison pour laquelle, il est nécessaire d'optimiser sa formulation, afin d'obtenir le meilleur compromis entre ses performances mécaniques, hygriques et thermiques, selon le domaine d'emploi (porteur et/ou isolant). La première piste d'optimisation envisagée consiste à faire varier le taux de granulats végétaux dans la composition du béton, mais aussi la nature et la quantité de liant utilisé. Le travail de cette thèse a pour objectif l'étude des propriétés mécaniques, thermiques et hygriques d'un béton de chanvre en fonction de sa formulation. Dans ce mémoire, on s'intéresse à la faisabilité de matériaux de construction légers à base de particules de chanvre et d'un liant à base de chaux, qui présentent de bonnes performances mécaniques. L'objectif principal ici est de réduire la concentration des ions Ca2+ libres responsables de la dégradation des particules végétales par minéralisation, et qui, par conséquent, induisent la perte de performance mécanique du matériau composite final. Pour y parvenir, une fraction du liant de base a été remplacée par du métakaolin qui interagit avec ces ions Ca2+ suivant une réaction pouzzolanique, afin d'empêcher leur migration vers les particules végétale. Dans un premier temps, nous avons étudié l'influence de différents pourcentages de métakaolin sur les liants témoins à base de chaux: chaux NHL5 et chaux préformulée Tradical PF70. Une étude préliminaire de caractérisation mécanique, en compression et en flexion, a permis suivant une approche "performantielle" de définir une formulation optimale des liants utilisés pour la fabrication des bétons étudiés. Ainsi, les matériaux composites finis sont testés pour différents pourcentages en volume (2V et 3V) de particules de chanvre. Les résultats de la caractérisation des propriétés physico-mécaniques de ces matériaux sont présentés et argumentés. Il en ressort une relation étroite entre la teneur en métakaolin et les propriétés physico-mécaniques du béton de chanvre, qui résulte de la réaction pouzzolanique. Des analyses microscopiques au MEB couplées à l'EDX ont montré une diminution de la zone de transition à l'interface particules de chanvre-liant, mais aussi une faible migration des ions Ca2+ responsables de la minéralisation des particules végétales. Puis, nous avons comparé les performances hygro-thermiques des bétons de chanvre formulés comprenant respectivement 2 volumes et 3 volumes de particules végétales pour un volume de liant, sans ou avec 20% de métakaolin, pourcentage optimal défini précédemment. Cette étude est particulièrement utile pour établir les proportions adéquates d'adjuvants à utiliser dans les bétons destinés aux travaux de rénovation ou aux constructions neuves. D'une manière générale et en fonction de la formulation, on obtient un matériau bon, voire excellent régulateur de l'humidité ambiante, avec des performances thermiques intéressantes pour l'isolation des bâtiments. Ce travail de caractérisation complète les nombreux travaux déjà réalisés sur les bétons biosourcés avec différents types de végétaux, et doit permettre d'alimenter les bases de données indispensables pour la simulation du comportement d'une paroi ou de l'enveloppe d'un bâtiment sous différents climats et garantir le confort des occupantsHemp concrete is one of the most popular bio-based building materials in France. It is often used as a filling and / or insulation material, in an eco-construction system. Given its high porosity, this concrete has particularly advantageous thermal and hygric performance. However, the lighter this hemp concrete, the higher its level of thermal insulation, while its mechanical properties decrease. This is why it is necessary to optimize its formulation, in order to obtain the best compromise between its mechanical, hygric and thermal performance, depending on the field of use (carrier and / or insulator). The first optimization approach considered consists in varying the rate of plant aggregates in the composition of the concrete, but also the nature and quantity of binder used. The objective of this thesis is to study the mechanical, thermal and hygric properties of a hemp concrete according to its formulation. In this thesis, we are interested in the feasibility of lightweight building materials based on hemp particles and a lime-based binder, which present good mechanical performances. The main objective is to overcome the migration process of free Ca2+ to the lumen of hemp particles that are responsible for their degradation and which, consequently, induce the loss of mechanical performance of the final composite material. To achieve this, a fraction of the base binder is replaced by metakaolin. First, we studied the influence of different percentages of metakaolin on the carbonation of two lime-based control mortars: NHL5 lime and Tradical PF70 pre-formulated lime. Then, we measured their mechanical resistances in compression and flexion in order to define an optimal formulation. Thus, the finished composite materials are tested for different volume percentages (2v and 3v) of hemp particles. The results of the characterization of the physico-mechanical properties of the specimens are presented and argued. A close relationship between the metakaolin content and the physico-mechanical properties of the hemp concrete has been observed, due to the additional hydration products derived from pozzolanic reaction mechanism. The MEB and EDX analyses have shown the enhancement of hemp particles-binder Interfacial Zone Transition, while the pozzolanic reaction leads to reduce the migration process of free Ca2+ to lumen of vegetable particles thus reducing their mineralization. Then, we compared the hygro-thermal performances of hemp concretes formulated with respectively 2 volumes and 3 volumes of plant particles for one volume of binder, without or with 20% metakaolin, the optimal percentage defined previously. This study is particularly useful to establish the adequate proportions of admixtures to be used in concretes intended for renovation works or new constructions. Generally speaking, and depending on the formulation, we obtain a material that is a good or even excellent regulator of ambient humidity, with interesting thermal performances for the insulation of buildings. This characterization work completes the many works already carried out on biobased concrete with different types of plants, and should make it possible to feed the databases essential for the simulation of the behavior of a wall or of the envelope of a building under different climates and guarantee the comfort of the occupants
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Saetung, Anuwat. "Preparation of polyurethane foams from hydroxytelechelic oligoisoprenes obtained by controlled degradation of natural rubber : study of their physico-mechanical, thermal, and acoustic properties." Le Mans, 2009. http://cyberdoc.univ-lemans.fr/theses/2009/2009LEMA1006.pdf.
Abstract:
Les mousses de polyuréthane constituent les matériaux polyuréthane les plus largement étudiés et utilisés pour de nombreuses applications telles que l'ameublement, l'automobile, l'isolation thermique et phonique. Les composés hydroxylés couramment utilisés pour la production des mousses de polyuréthane sont des produits issus de la pétrochimie (polyols à base de polyesters ou de polyéthers). Ces produits ont le désavantage d'être issus de sources non renouvelables pouvant provoquer des pollutions de l'environnement et risquant de se tarir à court terme. Le caoutchouc naturel constitue un matériau de base pour la synthèse des polyuréthanes particulièrement intéressant en tant que matériau issu d'une source renouvelable abondante, avec des propriétés mécaniques intéressantes et une structure chimique facilement modifiable. Dans ce travail, un nouveau caoutchouc naturel hydroxytéléchélique (HTNR) de fonctionnalité 2 a été obtenu par l'intermédiaire de réactions contrôlées d'époxydation et de clivage du caoutchouc naturel, suivies d'une réduction sélective des oligoisoprènes carbonyltéléchéliques obtenus. Ces HTNR de différentes masses molaires (1000-3400 g mol-1), ont été obtenus de façon reproductible et avec des rendements élevés. Des modifications chimiques de ces HTNR ont été effectuées par époxydation (10-35% EHTNR), hydrogénation et réactions d'ouverture des oxiranes. Les différentes microstructures de ces oligomères ont été caractérisées par FT-IR, RMN, SEC et MALDI-TOF MS. Leurs propriétés thermiques ont été déterminées par TGA et DSC. Des mousses de polyuréthane ont été préparée à partir d'HTNR et d'EHTNR de différentes masses molaires et de différents taux d'époxydation en une étape. Les structures chimiques, les caractéristiques physiques des mousses, leurs propriétés mécaniques, thermiques et acoustiques ont été déterminées et comparée à celles des mousses de polyuréthane analogues synthétisées à partir de polyols commerciaux. Les mousses de polyur‚thane à base d'HTNR ont une structure de cellules ouvertes de dimensions 0,38 à 0,47 mm. Les propriétés mécaniques varient selon les masses molaires des oligomères hydroxytéléchéliques : les mousses de polyuréthane issues d'HTNR1000 présentent des forces d'élongation et de compression supérieures à celles de leurs homologues commerciaux, mais l'élongation à la rupture est plus faible. Les mousses à base d'HTNR3400 présentent les meilleures propriétés élastiques. Pour la série des mousses à base d'EHTNR, les forces d'élongation et de compression augmentent avec l'augmentation des taux d'époxydation. Les mêmes résultats sont observés avec des quantités croissantes de butane-1,4-diol. Pour ce qui concerne les propriétés thermiques, les mousses de polyuréthane à base d'HTNR présentent une meilleure flexibilité à basse température que leurs homologues à base de polyols commerciaux. De plus, elles présentent d'excellentes propriétés d'absorption acoustiquePolyurethane foam (PUF) is the largest of polyurethane materials widely studied and used in many applications such as furniture, automobile, insulation, acoustic absorber. Hydroxyl compounds currently used in the production of PUF are petrochemical products (polyester and polyether polyols). However, they have some disadvantages as they are non-renewable resources, they may cause environmental pollution, and they tend to be exhausted in the near future. Natural rubber (NR) is an interesting choice to use as a starting material in PUF synthesis, due to the fact that they are renewable source, abundant polymer and they have good mechanical properties and are easy to chemically modify. In this work, a new hydroxytelechelic natural rubber (HTNR) having a hydroxyl functionality of 2 was successfully performed via controlled epoxidation and cleavage of natural rubber, following by a selective reduction reaction of the obtained carbonyltelechelic oligoisoprenes. These HTNR with different molecula r weights (1000-3400 g mol-1) were reproducible obtained with high yields. Chemical modifications on HTNR were performed by epoxidation (10-35%, EHTNR), hydrogenation and oxirane opening reactions. The different microstructures of these oligomers were evidenced by the characterization techniques FT-IR, NMR, SEC and MALDI-TOF MS. Their thermal properties were also investigated by TGA and DSC. Polyurethane foams were successfully prepared from a renewable source, HTNR with different molecular weights and EHTNR having a variation of epoxide content, by one shot technique. The chemical structure and cell structure as well as physico-mechanical, thermal and acoustic properties were characterized to compare with commercial polyol analogues. It was investigated that the obtained HTNR based foams are open cell structures and have cell dimensions between 0. 38 and 0. 47 mm. Concerning, physico-mechanical properties, HTNR1000 based foam exhibits higher tensile and compressive strengths than commercial polyol analogue, but the elongation at break is lower. However, HTNR3400 based foam shows the best for elastic properties. In series of EHTNR based foams, the tensile and compressive strengths give a trendy increasing with increasing the epoxide content. Same results were observed with increasing amount of 1,4-butanediol. For thermal properties, HTNR based foams show better low temperature flexibility than that based on commercial polyol. Moreover, HTNR based polyurethane foams give an excellent acoustic absorber
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Apreutesei, Mihai. "Temperature impact on thermal evolution of advanced PVD ceramic and metallic glass thin films : Physico-chemical and microstructural analysis." Thesis, Lyon, INSA, 2015. http://www.theses.fr/2015ISAL0009/document.
Abstract:
Ces dernières années, les exigences de l'industrie dans le développement de nouveaux matériaux fonctionnels en mesure de résister aux conditions difficiles pendant l'opération d'usinage sont en constante augmentation. Les chercheurs doivent donc trouver de nouvelles solutions pour répondre aux besoins industriels de plus en plus sévères. L’utilisation de revêtement protecteur à la surface de l’outil de coupe est une solution très efficace. Des nouveaux matériaux architecturés sont étudiés pour leurs propriétés mécaniques, physiques et chimiques uniques assurant une résistance aux dégradations de surface dues à la corrosion, l'usure, le frottement; en particulier lorsque ces outils sont utilisés dans des environnements hostiles. Dans le cadre de cette thèse de doctorat, l'influence de la température sur la stabilité structurale de deux types de films minces déposés par PVD a été étudiée. Des films céramiques et de verre métallique ont été envisagés. Afin de préparer et optimiser ces films, le projet s’est axé sur l'étude de l'influence des conditions de dépôt sur les caractéristiques de croissance du film: composition chimique, structure, morphologie, puis sur les changements ultérieurs des principales propriétés des films minces, à savoir la résistance à l’oxydation et à la cristallisation lors de leur utilisation à hautes températures. Une démarche multi-échelle a été développée pour caractériser au mieux les couches. La première partie du travail est liée aux revêtements céramiques à base de CrN pour donner de nouvelles fonctionnalités et améliorer la surface des outils de coupe dans le but essentiel d'accroître leur durée de vie. La seconde partie du manuscrit est dédiée aux films minces de verres métalliques de Zr-Cu préparés par un procédé de co-pulvérisation magnétron PVD. Le but de cette partie consiste en l’étude de la relation entre la structure amorphe de ces films et leurs propriétés mécaniques. La conservation du caractère amorphe de ces films en température présente également un caractère essentiel. Les verres métalliques ont récemment attiré un fort intérêt car ils présentent des propriétés mécaniques intéressantes à température ambiante. Ils présentent, de ce fait, un grand potentiel pour des applications d'ingénierie en raison de leurs caractéristiques mécaniques et physico-chimiques uniques (haute limite élastique, résistance à la corrosion ...). Pour relier les propriétés mécaniques des couches à l’évolution de leurs microstructures, une partie importante de ce travail a porté sur l’observation de l’évolution de la couche au cours du chauffage au moyen de techniques de caractérisation in situ. Les films minces proposés au cours de ce travail peuvent être envisagées pour un large gamme d’application dans l’ingénierie de surface pour protéger les surfaces et améliorer la durée de vie des matériauxIn the recent years the industrial requirements to develop new functional materials able to overcome the severe conditions during machining operation are continuously increasing. Researchers then must find novel solutions to respond to their severe industrial requirements. To coat the tool surface with advanced coatings is the most efficient solution. New nanostructured materials may nowadays exhibit unique mechanical, physical and chemical properties ensuring notable degradation resistance where the surface protection of materials against corrosion, wear, friction or oxidation is a key issue, particularly when operating in hostile environments. Within the scope of this Ph.D. thesis the influence of the temperature on the structural stability of two different PVD ceramic and metallic glass thin films is proposed. The main goal consists in the development of two distinct classes of thin films, with a wide range of properties. In order to prepare these films, the project will be focused on the study on the influence of PVD deposition conditions in the particular film’s growth characteristics: chemical composition, structure, morphology and the subsequent changes in the main properties of the thin films, namely oxidation and crystallization resistance, especially. For that purpose we adopted the multiscale approach. The first part is related to the ceramic CrN-based coatings to give new functionalities and improve the tools’ surface with the primary aim to increase their lifetime. Secondly, new protective materials able to better protect the exposed surfaces against high temperature oxidation have been proposed, namely CrAlN and CrAlYN coatings as will be evidenced in this manuscript. The second part of the manuscript is dedicated to the innovative Zr-Cu thin films metallic glasses prepared by a PVD magnetron co-sputtering method with the objective to investigate the amorphization ability and their structural properties. Their excellent properties at room temperature have recently attracted attention as a new class of materials with great potential for engineering applications due to unique mechanical and physico-chemical characteristics (high elastic strain limit, corrosion resistance…). Finally, an important approach during the course of this thesis was the real time observation of the structure and surface modifications during heating by means of in situ methods. The thin films proposed during the course of the work could be straightforward used as surface engineering solutions to protect and extend the lifetime of the materials and components
5
Sani, Rababe. "Étude des transformations microstructurales de mélanges argile/Combustibles Solides de Récupération (CSR) lors de la cuisson : relations entre propriétés physico-chimiques, mécaniques et thermiques." Thesis, Ecole nationale des Mines d'Albi-Carmaux, 2018. http://www.theses.fr/2018EMAC0005/document.
Abstract:
La valorisation des co-produits riches en matières organiques et inorganiques comme additifs dans des formulations à base d’argile peut améliorer à la fois les performances mécaniques et thermiques des produits de terre cuite, de même que le bilan énergétique des procédés de fabrication de ces matériaux. Cette étude a porté sur l’incorporation de combustibles solides de récupération (CSR) dans un mélange de fabrication des produits de terre cuite pour le génie civil en étroite collaboration avec l’entreprise TERREAL dans le cadre du projet LabCom RESPECTc financé par l’ANR.Premièrement, deux CSR ont été sélectionnés et utilisés comme additifs pour améliorer les produits issus des deux gisements de mélange argileux nommés ML et MC de chez TERREAL. L’influence de la nature, du taux d’incorporation des CSR, de la granulométrie des CSR et de la nature de la matrice argileuse sur les propriétés physico-chimiques, mécaniques et thermiques des mélanges argileux/CSR a été étudiée entre 30°C et 1100°C. Dans tous les cas, l’ajout de CSR a permis d’améliorer le caractère isolant des produits de terre cuite, en diminuant leur conductivité thermique. L’ajout de CSR a aussi permis d’améliorer les propriétés mécaniques des produits, en fonction du type et du taux de CSR ajouté, du taux et de la nature (forme, taille et distribution) de la porosité créée. L’étude a démontré que les interactions entre les minéraux argileux et les éléments inorganiques des CSR avaient un impact important sur les propriétés mécaniques et thermiques. Les résultats ont montré que l’ajout de 4% en masse du CSR15-1 contenant un taux de cendres de 65,7% en masse a conduit à une augmentation de la résistance mécanique du matériau à base de la matrice argileuse ML de l’ordre de 32%. Ensuite, un modèle cinétique du frittage basé sur les variations dimensionnelles des matériaux entre 650°C et 1000°C a été développé à partir de l’analyse thermomécanique (ATM) des mélanges (avec ou sans CSR). L’objectif a été de mieux comprendre les mécanismes du frittage mis en jeu. Le modèle développé a montré une bonne adéquation avec les données expérimentales. Les résultats ont montré que l’étape du frittage thermique de ces mélanges se fait en présence d’une phase liquide et que l’ajout de CSR a permis d’accélérer la densification des matériaux. Cela a conduit à une diminution de la température usuelle de cuisson des produits de terre cuite permettant ainsi un gain énergétique non négligeable. Finalement, une étude environnementale a été réalisée lors de la cuisson des mélanges argileux/CSR. Cette étude a particulièrement été focalisée sur la contribution de CSR au bilan énergétique et à l’impact des émissions des gaz critiques tels que le CO2, le CO et l’HCl. Les résultats ont montré que les émissions de CO2 et de CO lors de la cuisson des mélanges argileux/CSR ont augmenté en raison de la décomposition thermique de la matière organique des CSR et que moins de 50% en masse du chlore a été transformé en HCl (18-31 ppm). Le bilan énergétique effectué a montré que l’ajout de CSR au sein des matrices argileuses ML ou MC compense une part non négligeable du gaz naturel usuellement utilisé comme combustible au cours de la cuisson de ces matériaux. Cela s’est traduit par une économie d’énergie thermique et une réduction des émissions de CO2 provenant de la décarbonatation de la matrice argileuseThe valorization of co-products rich in organic and inorganic materials as additives in formulations based on clay matrix can improve both the mechanical and thermal performances of ceramic materials as well as the energy balance of the manufacturing processes of these products. This study focused on the incorporation of Solid Recovered Fuels (SRF) into the clay ceramics for civil engineering in close collaboration with TERREAL as part of the ANR funded LabCom RESPECTc project. Firstly, two SRF were selected and used as additives to improve the properties of ceramic materials from to clay mixture deposits named ML and MC from TERREAL. The influence of the nature, the amount of SRF, the grain size of SRF and the nature of clay matrix on the physico-chemical, mechanical and thermal properties of the clay/SRF mixtures were studied between 30°C and 1100°C. In all cases, the addition of SRF into the clay mixture (ML or MC) has enhanced the insulating nature of the ceramic materials by reducing their thermal conductivity. The addition of SRF has also improved the mechanical properties of the ceramic materials, depending on the nature and the amount of SRF added, the rate and the nature (shape, size and distribution) of the porosity created. The study demonstrated that interactions between clay minerals and inorganic elements of SRF have a significant effect on mechanical and thermal properties. The results showed that the addition of 4 wt.% of SRF15-1 containing an ash content of 65.7 wt.% into clay matrix ML led to increase the mechanical strength of the material based on the clay matrix ML of the order of 32%. Then, a kinetic model of thermal sintering based on the dimensional variations of ceramic materials between 650°C and 1000°C was developed from thermomechanical analysis (TMA) of the clay mixtures (with or without SRF). The main objective is to better understand the mechanism of the thermal sintering involved. The model developed showed a good adequacy with the experimental data. The results showed that the thermal sintering step of these mixtures is carried out by the presence of a liquid phase and that the addition of SRF has accelerated the densification of ceramic materials. This has led to decrease the usual firing temperature of ceramic materials, allowing a significant energy savings. Finally, an environmental assessment was carried out during the firing of clay/SRF mixtures. This study was particularly focused on the contribution of SRF to the energy balance and impact of critical gas emissions such as CO2, CO and HCl. The results showed that CO2 and CO emissions during firing of clay/SRF mixtures increased due to the thermal decomposition of the organic matter of SRF and that less than 50 wt.% of chlorine was converted to HCl (18-31 ppm). The energy balance showed that the addition of SRF into the ML matrix compensates for a significant part of the natural gas usually used as fuel during firing of these ceramic materials. This was reflected by a thermal energy saving and reduction of CO2 emissions from the decarbonatation of the clay matrix
6
Conley, Jill Anne. "Hygro-thermo-mechanical behavior of fiber optic apparatus." Thesis, Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/17308.
7
Sani, Rababe. "Étude des transformations microstructurales de mélanges argile/Combustibles Solides de Récupération (CSR) lors de la cuisson : relations entre propriétés physico-chimiques, mécaniques et thermiques." Electronic Thesis or Diss., Ecole nationale des Mines d'Albi-Carmaux, 2018. http://www.theses.fr/2018EMAC0005.
Abstract:
La valorisation des co-produits riches en matières organiques et inorganiques comme additifs dans des formulations à base d’argile peut améliorer à la fois les performances mécaniques et thermiques des produits de terre cuite, de même que le bilan énergétique des procédés de fabrication de ces matériaux. Cette étude a porté sur l’incorporation de combustibles solides de récupération (CSR) dans un mélange de fabrication des produits de terre cuite pour le génie civil en étroite collaboration avec l’entreprise TERREAL dans le cadre du projet LabCom RESPECTc financé par l’ANR.Premièrement, deux CSR ont été sélectionnés et utilisés comme additifs pour améliorer les produits issus des deux gisements de mélange argileux nommés ML et MC de chez TERREAL. L’influence de la nature, du taux d’incorporation des CSR, de la granulométrie des CSR et de la nature de la matrice argileuse sur les propriétés physico-chimiques, mécaniques et thermiques des mélanges argileux/CSR a été étudiée entre 30°C et 1100°C. Dans tous les cas, l’ajout de CSR a permis d’améliorer le caractère isolant des produits de terre cuite, en diminuant leur conductivité thermique. L’ajout de CSR a aussi permis d’améliorer les propriétés mécaniques des produits, en fonction du type et du taux de CSR ajouté, du taux et de la nature (forme, taille et distribution) de la porosité créée. L’étude a démontré que les interactions entre les minéraux argileux et les éléments inorganiques des CSR avaient un impact important sur les propriétés mécaniques et thermiques. Les résultats ont montré que l’ajout de 4% en masse du CSR15-1 contenant un taux de cendres de 65,7% en masse a conduit à une augmentation de la résistance mécanique du matériau à base de la matrice argileuse ML de l’ordre de 32%. Ensuite, un modèle cinétique du frittage basé sur les variations dimensionnelles des matériaux entre 650°C et 1000°C a été développé à partir de l’analyse thermomécanique (ATM) des mélanges (avec ou sans CSR). L’objectif a été de mieux comprendre les mécanismes du frittage mis en jeu. Le modèle développé a montré une bonne adéquation avec les données expérimentales. Les résultats ont montré que l’étape du frittage thermique de ces mélanges se fait en présence d’une phase liquide et que l’ajout de CSR a permis d’accélérer la densification des matériaux. Cela a conduit à une diminution de la température usuelle de cuisson des produits de terre cuite permettant ainsi un gain énergétique non négligeable. Finalement, une étude environnementale a été réalisée lors de la cuisson des mélanges argileux/CSR. Cette étude a particulièrement été focalisée sur la contribution de CSR au bilan énergétique et à l’impact des émissions des gaz critiques tels que le CO2, le CO et l’HCl. Les résultats ont montré que les émissions de CO2 et de CO lors de la cuisson des mélanges argileux/CSR ont augmenté en raison de la décomposition thermique de la matière organique des CSR et que moins de 50% en masse du chlore a été transformé en HCl (18-31 ppm). Le bilan énergétique effectué a montré que l’ajout de CSR au sein des matrices argileuses ML ou MC compense une part non négligeable du gaz naturel usuellement utilisé comme combustible au cours de la cuisson de ces matériaux. Cela s’est traduit par une économie d’énergie thermique et une réduction des émissions de CO2 provenant de la décarbonatation de la matrice argileuseThe valorization of co-products rich in organic and inorganic materials as additives in formulations based on clay matrix can improve both the mechanical and thermal performances of ceramic materials as well as the energy balance of the manufacturing processes of these products. This study focused on the incorporation of Solid Recovered Fuels (SRF) into the clay ceramics for civil engineering in close collaboration with TERREAL as part of the ANR funded LabCom RESPECTc project. Firstly, two SRF were selected and used as additives to improve the properties of ceramic materials from to clay mixture deposits named ML and MC from TERREAL. The influence of the nature, the amount of SRF, the grain size of SRF and the nature of clay matrix on the physico-chemical, mechanical and thermal properties of the clay/SRF mixtures were studied between 30°C and 1100°C. In all cases, the addition of SRF into the clay mixture (ML or MC) has enhanced the insulating nature of the ceramic materials by reducing their thermal conductivity. The addition of SRF has also improved the mechanical properties of the ceramic materials, depending on the nature and the amount of SRF added, the rate and the nature (shape, size and distribution) of the porosity created. The study demonstrated that interactions between clay minerals and inorganic elements of SRF have a significant effect on mechanical and thermal properties. The results showed that the addition of 4 wt.% of SRF15-1 containing an ash content of 65.7 wt.% into clay matrix ML led to increase the mechanical strength of the material based on the clay matrix ML of the order of 32%. Then, a kinetic model of thermal sintering based on the dimensional variations of ceramic materials between 650°C and 1000°C was developed from thermomechanical analysis (TMA) of the clay mixtures (with or without SRF). The main objective is to better understand the mechanism of the thermal sintering involved. The model developed showed a good adequacy with the experimental data. The results showed that the thermal sintering step of these mixtures is carried out by the presence of a liquid phase and that the addition of SRF has accelerated the densification of ceramic materials. This has led to decrease the usual firing temperature of ceramic materials, allowing a significant energy savings. Finally, an environmental assessment was carried out during the firing of clay/SRF mixtures. This study was particularly focused on the contribution of SRF to the energy balance and impact of critical gas emissions such as CO2, CO and HCl. The results showed that CO2 and CO emissions during firing of clay/SRF mixtures increased due to the thermal decomposition of the organic matter of SRF and that less than 50 wt.% of chlorine was converted to HCl (18-31 ppm). The energy balance showed that the addition of SRF into the ML matrix compensates for a significant part of the natural gas usually used as fuel during firing of these ceramic materials. This was reflected by a thermal energy saving and reduction of CO2 emissions from the decarbonatation of the clay matrix
8
Cunha, Paulo Waldemiro Soares. "Estudo sobre as potencialidades de comp?sitos ? base de gesso e fibras de coco seco para aplica??o na constru??o civil." Universidade Federal do Rio Grande do Norte, 2012. http://repositorio.ufrn.br:8080/jspui/handle/123456789/12847.
Abstract:
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Previous issue date: 2012-12-28The use of gypsum, one of the oldest building materials for the construction industry in the country has been experiencing a significant and steady growth, due to its low cost and some of its properties that confer comparative advantage over other binder materials. Its use comprises various applications including the coating of walls and the production of internal seals and linings. Moreover, the fibers are being increasingly incorporated into arrays fragile in an attempt to improve the properties of the composite by reducing the number of cracks, the opening of the same and its propagation velocity. Other properties, depending on the function of the component material or construction, among these thermal and acoustic performances, are of great importance in the context of buildings and could be improved, that is, having better performance with this embodiment. Conduct a comparative study of physico-mechanical, thermal and acoustic composite gypsum incorporating dry coconut fiber, in the form of blanket, constituted the main objective of this work. Improving the thermal and acoustic performances of precast gypsum, used for lining and internal vertical fences of buildings, was the purpose of development of these composites. To evaluate the effect of fiber content on the properties of the composites were used to manufacture the composite layer with different thicknesses. The composites were fabricated in the form of plates with dimensions of 500x500x24mm. To facilitate the comparative study of the properties were also made with material gypsum boards only. We then determined the physico-mechanical, thermal and acoustical plaster and composites. The results indicated that the composites were significant gains in relation to thermal performance and also acoustic, in certain frequency range, increasing the thickness of the blanket. Concerning other physical-mechanical properties, the results showed that although the compressive strength was lower than for the composite did not occur after a fracture catastrophic failure. The same trend was observed with regard to resistance to bending, since the composites have not suffered sudden rupture and still continued after the load supporting point of maximum load
A utiliza??o do gesso, um dos mais antigos materiais de constru??o, pela ind?stria da constru??o civil no Pa?s, vem experimentando um sens?vel e constante crescimento, em fun??o do seu baixo custo e de algumas de suas propriedades que lhe conferem vantagem comparativa em rela??o a outros materiais ligantes. Sua utiliza??o compreende diversas aplica??es entre as quais o revestimento de paredes e a confec??o de veda??es internas e de forros. Por outro lado, as fibras v?m sendo, cada vez mais, incorporadas em matrizes fr?geis, na tentativa de melhorar as propriedades do comp?sito, atrav?s da redu??o do n?mero de fissuras, da abertura das mesmas e da sua velocidade de propaga??o. Dependendo da fun??o do material ou do componente da constru??o, os desempenhos t?rmico e ac?stico, assumem grande import?ncia no contexto das edifica??es e tamb?m poderiam ser melhoradoscom a incorpora??o de fibras. Dentre as fibras vegetais, a fibra de coco seco apresenta um grande potencial, superior ?s vantagens comparativas das demais fibras, tal como uma maior resist?nciafrente ? alcalinidade caracter?stica das matrizes ciment?cias. Realizar um estudo comparativo das propriedades f?sico-mec?nicas, t?rmicas e ac?sticas de comp?sitos ? base de gesso com incorpora??o de fibra de coco seco, sob a forma de manta, constituiu-se no objetivo geral deste trabalho. Para tanto os materiais comp?sitos foram confeccionados em forma de placas, pain?is sandu?ches, com dimens?es de 500x500x24mm, sendo as camadas externas constitu?das pelogesso e a central (recheio) pela manta de fibra de coco seco. Para avaliar a influ?ncia do teor de fibras nas propriedades dos comp?sitos foram utilizadas na confec??o dos mesmos mantas com espessuras de 8 e 10 mm. Para possibilitar o estudo comparativo das propriedades foram tamb?m confeccionadas placas apenas com gesso. Foram ent?o determinadas as propriedades f?sico-mec?nicas, t?rmicas e ac?sticas do gesso e dos comp?sitos. Os resultados indicaram que para os comp?sitos ocorreram ganhos significativos em rela??o aos desempenhos t?rmico e tamb?m ac?stico, na faixa de frequ?ncia de 102,28 Hz a 1.150,00 Hz, ganhos esses crescentes com a espessura da manta. Em rela??o ?s demais propriedades f?sico-mec?nicas, os resultados mostraram que embora a resist?ncia ? compress?o tenha sido inferior para os comp?sitos, as fibras apenas evitaram um rompimento brusco, uma vez que as mesmas n?o atuam como refor?o para esse tipo de solicita??o. O mesmo comportamento ocorreu em rela??o ? resist?ncia ? flex?o, uma vez que os comp?sitos n?o sofreram ruptura brusca e ainda continuaram suportando carga depois do ponto de carga m?xima
9
Cisse, Ousseynou. "Caractérisation du comportement hygro-mécanique des fibres liberiennes élémentaires issues du chanvre." Thesis, Besançon, 2014. http://www.theses.fr/2014BESA2031/document.
Abstract:
Ce travail de thèse, s'inscrit dans un accord co-tutelle entre l’École Polytechnique de Thiès du Sénégal, et de l'Université de Franche-Comté. Il a été réalisé au Département de Mécanique Appliquée de l'institut FEMO-ST à Besançon (France). [...]L'objectif de cette thèse est de contribuer à la caractérisation du comportement thermo-hygro-mécaniques des fibres libériennes élémentaires issues du chanvre. Les fibres élémentaires testées dans ce travail ont des diamètres extérieurs moyens d'environ 20µm et des longueurs utiles de l'ordre de 10mm. Des essais couplant des chargements mécaniques, hygroscopiques et thermiques sont réalisés afin d'apporter des éléments de compréhension sur le comportement des fibres et de collecter une base de données sur leurs performances mécaniques.Trois types de comportement sont identifiés sur les fibres en traction quasi statique en fluage pour les différents niveaux hygro-thermique testés. Une rigidification de la fibre est révélée sous chargements cycliques progressifs dans des conditions environnementales constantes. Une chute du module d' Young initial de la fibre est remarquée quand l'humidité relative augmente. Une accélération de la vitesse de déformation différée de la fibre est obtenue en fluage lorsque des cycles d'humidité relative sont appliqués. Une baisse des propriétés mécaniques des fibres sous l'effet de la température est également observée. Elle dépend directement du niveau de la durée de l'exposition à la températureThe thesis work joins in the framework in joint supervision between the Polytechnic school in Thies (Sénégal) and the University of Franche-Comté (France)[...]The aim of this thesis is to contribute to the characterization of thermo-hygro-mechanical behaviour of elementary hemp fibres. These fibres used in this work have an average diameter approximately 20µm and useful length of only 10 mm. The méchanical, hygroscopic and thermal coupling testing are realized to provide some understanding of the behaviour of the hemp fibres and to collect details from a database on their mechanical performance.From the uniaxial quasi static tensile tests and creep tests, three categories of behaviours are measured and observed. How ever subject to constant environmental conditions, a fibre hardening is observed under cyclic tensile loading. It was also found that a drop of the initial Young 's modulus of the hemp fibres when the relative humidity gradually increases. Thus, the strain rates measured on the fibres during creep exhibited a speeding up relative humidity cycles are imposed . We found also that the mechanical properties of the fibres decrease under temperature effects. It depends directly on the level and exposure time to temperature
10
Cohen, Ellann. "Thermal properties of advanced aerogel insulation." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/67795.
Abstract:
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2011.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 74-76).
Buildings consume too much energy. For example, 16.6% of all the energy used in the United States goes towards just the heating and cooling of buildings. Many governments, organizations, and companies are setting very ambitious goals to reduce their energy use over the next few years. Because the time periods for these goals are much less than the average lifetime of a building, existing buildings will need to be retrofitted. There are two different types of retrofitting: shallow and deep. Shallow retrofits involve the quickest and least expensive improvements often including reducing infiltration around windows, under doors, etc and blowing more insulation into the attic. Deep retrofits are those that involve costly renovation and typically include adding insulation to the walls and replacing windows. A new, easily installable, inexpensive, and thin insulation would move insulating the walls from the deep retrofit category to the shallow retrofit category and thus would revolutionize the process of retrofitting homes to make them more energy efficient. This thesis provides an overview of a concept for a new, easily installable, inexpensive, thin aerogel-based insulation and goes into detail on how the thermal properties of the aerogel were measured and validated. The transient hot-wire method for measuring the thermal conductivity of very low thermal conductivity silica aerogel (1 0mW/m K at 1 atm) along with a correction for end effects was validated with the NIST (National Institute of Standards and Technology) Standard Reference Material 1459, fumed silica board to within 1 mW/mK. Despite the translucence of the aerogel at certain wavelengths, radiation is not an issue through the aerogel during the hot-wire test but may be an issue in actual use as an insulation. The monolithic aerogel thermal conductivity drops significantly with slightly reduced pressure (3.2 mW/m K at 0.1atm). For the final composite insulation, the new silica aerogel formula is a great choice and it is recommended to reduce the pressure around the aerogel to 1 / 1 0 th. In the future, a prototype of an insulation panel combining a 3-D truss structure, monolithic or granular silica aerogel, and reduced pressure will be constructed and tested.
by Ellann Cohen.
S.M.
Books on the topic "Physico-Mechanical and hygro-Thermal properties":
1
Marghussian, V. K. Thermo-mechanical properties of ceramic fibres. Carnforth, Lancashire, England: Parthenon Press, 1986.
2
Menard, Kevin Peter. Dynamic mechanical analysis: A practical introduction. Boca Raton, Fla: CRC Press, 1999.
3
David, Porter. Group interaction modelling of polymer properties. New York: M. Dekker, 1995.
4
Taya, Minoru. Metal matrix composites: Thermomechanical behavior. Oxford: Pergamon, 1989.
5
Liu, Wei. Thermische Stabilität und mechanische Eigenschaften quasikristalliner Legierungen. Düsseldorf: VDI, 1993.
6
Taya, Minoru. Metal matrix composites: Thermomechanical behavior. Oxford, England: Pergamon Press, 1989.
7
McManus, Hugh L. N., 1958-, Bowles Kenneth J, and Lewis Research Center, eds. Mechanical properties of degraded PMR-15 resin. [Cleveland, Ohio]: National Aeronautics and Space Administration, Lewis Research Center, 1998.
8
A, Schneider Gerold, Petzow G, North Atlantic Treaty Organization. Scientific Affairs Division., and NATO Advanced Research Workshop on the Thermal Shock and Thermal Fatigue Behavior of Advanced Ceramics (1992 : Munich, Germany), eds. Thermal shock and thermal fatigue behavior of advanced ceramics. Dordrecht: Kluwer Academic Publishers, 1993.
9
M, Steen, and Lohr R. D, eds. Ultra high temperature mechanical testing. Cambridge: Woodhead, 1995.
10
Campbell, Christian X. Databook on mechanical and thermophysical properties of particulate-reinforced ceramic matrix composites. West Lafayette, IN: Ceramics Information Analysis Center, Center for Information and Numerical Data Analysis and Synthesis, Purdue University, 1995.
Book chapters on the topic "Physico-Mechanical and hygro-Thermal properties":
1
Rahman, M. R., S. Hamdan, and J. C. H. Lai. "Physico-mechanical, Morphological, and Thermal Properties of Clay Dispersed Styrene-co-Maleic Acid Impregnated Wood Polymer Nanocomposites." In Wood Polymer Nanocomposites, 179–97. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-65735-6_10.
2
Rahman, M. R., J. C. H. Lai, and S. Hamdan. "Acrylonitrile/Butyl Methacrylate/Halloysite Nanoclay Impregnated Sindora Wood Polymer Nanocomposites (WPNCs): Physico-mechanical, Morphological and Thermal Properties." In Wood Polymer Nanocomposites, 237–56. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-65735-6_13.
3
Rahman, M. R., J. C. H. Lai, and S. Hamdan. "Nanoclay Dispersed Furfuryl Alcohol-co-Ethyl Methacrylate Wood Polymer Nanocomposites: The Enhancement on Physico-mechanical and Thermal Properties." In Wood Polymer Nanocomposites, 275–93. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-65735-6_15.
4
Kumar, Rajesh, Rajni Lakhani, and Ashok Kumar. "Physico-Mechanical and Thermal Properties of Lightweight Structural Concrete with Light Expanded Clay Aggregate for Energy-Efficient Buildings." In Lecture Notes in Civil Engineering, 175–85. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-16-6557-8_14.
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Rahman, M. R., S. Hamdan, and J. C. H. Lai. "Physico-Mechanical, Thermal, and Morphological Properties of Styrene-co-3-(Trimethoxysilyl)Propyl Methacrylate with Clay Impregnated Wood Polymer Nanocomposites." In Wood Polymer Nanocomposites, 219–36. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-65735-6_12.
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Benboudjema, Farid, Jérôme Carette, Brice Delsaute, Tulio Honorio de Faria, Agnieszka Knoppik, Laurie Lacarrière, Anne Neiry de Mendonça Lopes, Pierre Rossi, and Stéphanie Staquet. "Mechanical Properties." In Thermal Cracking of Massive Concrete Structures, 69–114. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-76617-1_4.
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Janssen, Jules J. A. "Thermal expansion." In Mechanical Properties of Bamboo, 11. Dordrecht: Springer Netherlands, 1991. http://dx.doi.org/10.1007/978-94-011-3236-7_2.
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Vollath, D. "Mechanical and Thermal Properties." In U Uranium, 1–205. Berlin, Heidelberg: Springer Berlin Heidelberg, 1986. http://dx.doi.org/10.1007/978-3-662-10719-5_1.
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Irwin, Patricia, Wei Zhang, Yang Cao, Xiaomei Fang, and Daniel Qi Tan. "Mechanical and Thermal Properties." In Dielectric Polymer Nanocomposites, 163–96. Boston, MA: Springer US, 2009. http://dx.doi.org/10.1007/978-1-4419-1590-0_6.
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Irwin, Patricia, Wei Zhang, Yang Cao, Xiaomei Fang, and Daniel Qi Tan. "Mechanical and Thermal Properties." In Dielectric Polymer Nanocomposites, 163–96. Boston, MA: Springer US, 2009. http://dx.doi.org/10.1007/978-1-4419-1591-7_6.
Conference papers on the topic "Physico-Mechanical and hygro-Thermal properties":
1
LECHHEB, Mahdi. "Mechanical and Thermal Properties of Goulmima’s Earth Bricks." In Mediterranean Architectural Heritage. Materials Research Forum LLC, 2024. http://dx.doi.org/10.21741/9781644903117-21.
Abstract:
Abstract. Earthen constructions are prevalent in the Drâa-Tafilalet region of Morocco, yet there is a notable absence of comprehensive studies on the mud bricks used in these structures. This research endeavors to characterize a quarry utilized by Goulmima residents for mud brick production. Various techniques, including physico-chemical analysis (XRD, IR, FX, etc.), microscopic examination (SEM), and geotechnical assessments (Atterberg limits, grain size, etc.), were employed to analyze samples from the site. The bricks, formed at different firing temperatures, were blended with naturally crushed date palm seeds. The chemical composition, firing temperatures, and organic matter percentage directly influence mechanical properties and thermal conductivity. Material compressive strength exhibited a proportional increase with rising firing temperatures, peaking at 850°C. Conversely, elevating the percentage of crushed palm seed had an adverse impact on mechanical strength.
2
Badan, Aleksandra, and Tomasz Majka. "The influence of vegetable-oil based polyols on physico-mechanical and thermal properties of polyurethane foams." In The 21st International Electronic Conference on Synthetic Organic Chemistry. Basel, Switzerland: MDPI, 2017. http://dx.doi.org/10.3390/ecsoc-21-04763.
3
Arju, S. N., and A. M. Afsar. "Improvement of physico-mechanical and thermal properties of jute PP composites by using reactive dye and chemicals." In Proceedings of the 13th International Conference on Mechanical Engineering (ICME2019). AIP Publishing, 2021. http://dx.doi.org/10.1063/5.0037777.
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Park, Seungbae, Jae Kwak, Haojun Zhang, Xin Zhang, and Siu-Lung Ng. "Conjugate Effect of Hygro and Thermo-Mechanical Behavior in MEMS Packages." In ASME 2010 International Mechanical Engineering Congress and Exposition. ASMEDC, 2010. http://dx.doi.org/10.1115/imece2010-39756.
Abstract:
This paper is to study the combined behavior of plastic encapsulated MEMS package under humid and elevated temperature environments. Although thermal-induced stress for the materials used in the MEMS package is already fully understood, moisture-induced stress is still not well studied. To cope with humidity effects on the MEMS package, the moisture-induced properties of mold compound are obtained from the proposed experiments. From the weight gain/loss measurement, saturated moisture content and diffusivity were obtained by curve fitting following Fick’s law. In addition, using digital image correlation (DIC) together with precision weight scale, coefficient of hygroscopic swelling (CHS) could also be obtained at different temperatures. The experimental results show that the diffusion coefficient of mold compound material follows Arrhenius’s equation well. Also, it is shown that the CHS of mold compound increases as temperature increases. Finally, using these experimentally obtained moisture properties, conjugated behavior (thermo-hygro-mechanical) of MEMS package under high temperature and humid environment could be estimated through numerical analysis by adopting classical analogy method. The numerical result was also validated by comparing with experimentally obtained warpage of MEMS package at elevated temperatures.
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Reddy, D. Harinadha, and Ananth Ramaswamy. "Degradation of concrete elements under thermal and mechanical loads and its repair." In IABSE Congress, Christchurch 2021: Resilient technologies for sustainable infrastructure. Zurich, Switzerland: International Association for Bridge and Structural Engineering (IABSE), 2021. http://dx.doi.org/10.2749/christchurch.2021.0737.
Abstract:
<p>Details of an experimental program comprising of concrete cylinders exposed to different combinations of uniaxial loading, temperature and exposure time, to assess change in its stiffness and strength properties is discussed. Further, an attempt to repair companion thermo-mechanically damaged cylinders using carbon fiber reinforced polymer (CFRP) for mechanical strengthening and geopolymer for thermal insulation before exposing them to combinations of mechanical load and temperature is also presented to assess the efficacy of this system. A Hygro-thermo-chemo mechanical model that has been discussed in the literature is used to obtain strains both in the primary concrete and in the insulated repaired system. Concrete is treated as a deformable, multiphase porous material and so is the geo-polymer repair material. FRP is treated as an elastic brittle material.</p>
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Mesli, Imane Fatima Zohra, Ahmed Soufiane Benosman, Omar Taleb, and Farid Brahim Houti. "Study of the Influence of Various Wastes on the Physico-Mechanical and Thermal Properties of Plaster Composite Materials." In 2024 ASU International Conference in Emerging Technologies for Sustainability and Intelligent Systems (ICETSIS). IEEE, 2024. http://dx.doi.org/10.1109/icetsis61505.2024.10459596.
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Kharlamov, Yu A., and M. Y. Kharlamov. "A Systems Approach for Analyzing Structure-Property Relationships in Thermal Sprayed Coatings." In ITSC2004, edited by Basil R. Marple and Christian Moreau. ASM International, 2004. http://dx.doi.org/10.31399/asm.cp.itsc2004p0753.
Abstract:
Abstract The short description of traditional methods of thermal sprayed coatings (TSC) structure characterization is given. The main parameters of structure and physico-mechanical properties of TSC, which influenced on their wear resistance are considered. The system approach for analyses of structure of TSC and the scheme of TSC properties prediction is proposed. The classification of structure levels of wear resistant coatings, obtained by thermal spraying, and models of their elements are proposed. The advisability of use of methods of structure-simulation modeling of TSC is shown.
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Saidi, Mohammed. "STUDY OF THE PHYSICO-MECHANICAL AND THERMAL PROPERTIES OF SELF-COMPACTING CONCRETES MADE FROM HIGH ALUMINA REFRACTORY BRICKS WASTE FILLERS." In 18th International Multidisciplinary Scientific GeoConference SGEM2018. Stef92 Technology, 2018. http://dx.doi.org/10.5593/sgem2018/4.2/s18.024.
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Cipri, F., C. Bartuli, T. Valente, and F. Casadei. "Electromagnetic and Mechanical Properties of Silica - Aluminosilicates Plasma Sprayed Composite Coatings." In ITSC2007, edited by B. R. Marple, M. M. Hyland, Y. C. Lau, C. J. Li, R. S. Lima, and G. Montavon. ASM International, 2007. http://dx.doi.org/10.31399/asm.cp.itsc2007p0507.
Abstract:
Abstract The physico-chemical and thermo-mechanical properties of aluminosilicate ceramics (high melting point, low thermal expansion coefficient, excellent thermal shock resistance, low density and good corrosion resistance) make this class of materials a good option for high temperature structural applications. Al2O3-SiO2 compounds show an excellent refractory behaviour allowing a wide use as wear resistant thermal barrier coatings, in metallurgical and glass plants and in high temperature heat exchangers. Moreover the low values of thermal expansion coefficient and of complex permittivity allow to extend the use of this ceramic for microelectronic devices, radome for antennas and electromagnetic windows for microwaves and infrared. The present paper presents the results of an extensive experimental activity carried out to produce thick aluminosilicate coatings by plasma spray technique. APS deposition parameters were optimized on the basis of a surface response approach, as specified by design of experiments (DoE) methodologies. Samples were tested for phase composition, total porosity, microstructure, microhardness, deposition efficiency, fracture toughness and modulus of rupture. Finally, coatings were characterized for their particularly interesting electromagnetic properties: complex permittivity was measured at microwave frequency using a network analyzer with wave guide.
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Šebestová, Pavlína, Vít Černý, and Rostislav Drochytka. "The influence of the fireclay waste on the microstructure and the physico-mechanical properties of autoclaved aerated concrete." In The 13th international scientific conference “Modern Building Materials, Structures and Techniques”. Vilnius Gediminas Technical University, 2019. http://dx.doi.org/10.3846/mbmst.2019.128.
Abstract:
Autoclaved aerated concrete is a building material with good thermal insulation properties, which it receives through the pore structure. The production of autoclaved aerated concrete consists of two phases. In the first stage, a porous structure is formed by the reaction of calcium hydroxide and aluminum powder to form hydrogen. In the second stage, the lime and siliceous components react under hydrothermal conditions to form crystalline calcium hydrosilicates which form a binder component in the material. In this paper, the degree of crystallization of calcium hydrosilicates is studied depending on the quantity and fineness of the admixture of the fireclay waste. The effect of three different sizes of the specific surface of the fireclay waste on the microstructure and physico-mechanical properties of the autoclaved aerated concrete was monitored. At the same time, the influence of sand substitute for waste was monitored. The amount of the substitute was 10%, 30% and 50%. Finally, the influence of the fireclay waste admixture on the autoclaved aerated concrete porous structure was assessed. The microstructure was analyzed by X-ray diffraction. Based on the achieved values, it can be said that the admixutre of fireclay waste has a positive effect on the crystallisation of calcium hydosilicate phases. Fireclay waste substitution is possible up to 50%. With a higher amount of substitution, the increasing pressure of autoclaved aerated concrete compression is monitored.
Reports on the topic "Physico-Mechanical and hygro-Thermal properties":
1
Hardy, Robert Douglas, David R. Bronowski, Moo Yul Lee, and John H. Hofer. Mechanical properties of thermal protection system materials. Office of Scientific and Technical Information (OSTI), June 2005. http://dx.doi.org/10.2172/923159.
2
Barnes, Eftihia, Jennifer Jefcoat, Erik Alberts, Hannah Peel, L. Mimum, J, Buchanan, Xin Guan, et al. Synthesis and characterization of biological nanomaterial/poly(vinylidene fluoride) composites. Engineer Research and Development Center (U.S.), September 2021. http://dx.doi.org/10.21079/11681/42132.
Abstract:
The properties of composite materials are strongly influenced by both the physical and chemical properties of their individual constituents, as well as the interactions between them. For nanocomposites, the incorporation of nano-sized dopants inside a host material matrix can lead to significant improvements in mechanical strength, toughness, thermal or electrical conductivity, etc. In this work, the effect of cellulose nanofibrils on the structure and mechanical properties of cellulose nanofibril poly(vinylidene fluoride) (PVDF) composite films was investigated. Cellulose is one of the most abundant organic polymers with superior mechanical properties and readily functionalized surfaces. Under the current processing conditions, cellulose nanofibrils, as-received and 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO) oxidized, alter the crystallinity and mechanical properties of the composite films while not inducing a crystalline phase transformation on the 𝛾 phase PVDF composites. Composite films obtained from hydrated cellulose nanofibrils remain in a majority 𝛾 phase, but also exhibit a small, yet detectable fraction of 𝛼 and ß PVDF phases.
3
Okuniewski, Maria, Vikas Tomar, Xianming Bai, Chaitanya Deo, Benjamin Beeler, and Yongfeng Zhang. Microstructure, Thermal, and Mechanical Properties Relationships in U and UZr Alloys. Office of Scientific and Technical Information (OSTI), June 2020. http://dx.doi.org/10.2172/1632268.
4
Tanrikulu, Ahmet. Microstructure and Mechanical Properties of Additive Manufacturing Titanium Alloys After Thermal Processing. Portland State University Library, January 2000. http://dx.doi.org/10.15760/etd.5972.
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Ramos, Nuno M. M., Joana Maia, Rita Carvalho Veloso, Andrea Resende Souza, Catarina Dias, and João Ventura. Envelope systems with high solar reflectance by the inclusion of nanoparticles – an overview of the EnReflect Project. Department of the Built Environment, 2023. http://dx.doi.org/10.54337/aau541621982.
Abstract:
High reflectance materials constitute an attractive idea to reduce cooling loads, which is crucial for attaining the Nearly Zero Energy Buildings goal, also presenting the benefit of broadening the range of colours applicable in building facades. The EnReflect project intended to re-design envelope systems by increasing their solar reflectance through nanotechnology. The main idea was to produce novel nanomaterial-based coatings with high near-infrared (NIR) reflectance by tuning their optical properties and testing their compatibility with typical insulation technologies such as ETICS. As such, this project focused on the synthesis of nanoparticles with improved NIR reflectance, the evaluation of the hygrothermal-mechanical behaviour of thermal insulation systems with the application of the improved coating solutions, the characterization of the more relevant material properties and the durability assessment. One of the main achievements was the development of a facile synthesis of a nanocomposite with improved performance in the NIR region that allowed the reflectance improvement of a dark-finishing coating. Also, the incorporation of such nanoparticles had a positive effect on keeping their optical properties after accelerated ageing cycles. The development of numerical simulations allowed the estimation of the maximum surface temperature in Mediterranean climates under different optical parameters. The study of the hygrothermal behaviour of thermal enhanced façades led to the development of a new durability assessment methodology which contributed to closing a standardization gap.
6
Chopra, O. K. Estimation of mechanical properties of cast stainless steels during thermal aging in LWR systems. Office of Scientific and Technical Information (OSTI), October 1991. http://dx.doi.org/10.2172/142528.
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Jackson, T. B., S. Y. Limaye, and W. D. Porter. The effects of thermal cycling on the physical and mechanical properties of [NZP] ceramics. Office of Scientific and Technical Information (OSTI), December 1994. http://dx.doi.org/10.2172/102179.
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Simon, N. J., E. S. Drexler, and R. P. Reed. Review of cryogenic mechanical and thermal properties of Al-Li alloys and Alloy 2219. Gaithersburg, MD: National Institute of Standards and Technology, 1991. http://dx.doi.org/10.6028/nist.ir.3971.
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Gill. L51675 Effects of Weldment Property Variations on the Behavior of Line Pipe. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), January 1993. http://dx.doi.org/10.55274/r0010133.
Abstract:
A steel weldment is a composite of zones or layers of different microstructures that possess different material properties. The zones include the base metal (or the sections of pipe), the weld metal, and a complex heat-affected zone (HAZ) of base metal that has been exposed to a variety of thermal cycles resulting in varying microstructures. The material properties of primary concern with respect to the mechanical behavior of the pipe are the stress-strain response (the constitutive properties) and the resistance to initiation and propagation of cracks or tears in the presence of a crack, notch, or other stress concentrator (the fracture toughness properties). Most of the experimental data on the behavior of welds with significant discontinuities were obtained from test specimens with surface or through-thickness notches or cracks. These data typically show an increase in load or nominal ductility for overmatched welds and a decrease in load or nominal ductility for undermatched welds. However, there are cases where the presence of a soft zone may enhance the nominal ductility and cases where overmatched welds will decrease the nominal ductility. The latter is especially likely in a girth weld with a circumferential crack in the HAZ.
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Veer, J. van der, and J. van Wortel. L51758 Non-Destructive Assurance of Quality of Heat-Treated Fittings. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), March 1997. http://dx.doi.org/10.55274/r0010338.
Abstract:
Sometimes heat treated components fail to pass the specified minimum mechanical requirements (yield strength, Charpy V-notch toughness). The influence of the complete heat cycle on the end results is not well understood and without a N.D.T. method for determining these properties the pipeline companies have difficulty in determining acceptable and non-acceptable individual components. In the quality control process for heat treated components, it is important to have a non-destructive testing technique available for predicting the yield strength and, if necessary, Charpy V-notch properties. In order to quantify the influence of the thermal cycle on the essential mechanical properties of plate material FeE355 and evaluate a promising N.D.T method for predicting yield strength and toughness, five heats of plate material FeE355 received ten different normalizing heat treatments (combinations of three different austenitizing temperatures and 4 heating/cooling rates). The heat treatment conditions were chosen to obtain a wide range of ferrite grain sizes/yield strengths. Together with the as-delivered conditions 55 conditions of plate material FeE355 were examined. Theexamination included:- Ferrite grain size measurements directly on the outer surface of the material (after removal of the decarburized zone) by means of replicas.- Tensile tests at 20�C, in twofold for all 55 conditions.- Charpy V impact tests at three temperatures, each in threefold for all 55 conditions.- Ferrite grain size measurements on cross sections of one of the threaded ends of all 110 tensile specimens.