Dissertations / Theses on the topic 'Thermomechanical behaviour'
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Tan, Geraldine. "Thermomechanical behaviour of NiTi." University of Western Australia. School of Mechanical Engineering, 2005. http://theses.library.uwa.edu.au/adt-WU2005.0111.
Full textTan, Geraldine. "Thermomechanical behaviour of NiTi /." Connect to this title, 2004. http://theses.library.uwa.edu.au/adt-WU2005.0111.
Full textMathew, J. "Thermomechanical behaviour of modified asphalts." Thesis(M.Sc.), CSIR-National Chemical Laboratory, Poona, 1987. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/3294.
Full textGarry, James Robert Creighton. "Coring planetary ices : their thermomechanical behaviour." Thesis, Open University, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.531067.
Full textLe, Thi Hong Nhan. "Self organising polymers : thermomechanical and electromechanical behaviour." Thesis, University of Sheffield, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.500216.
Full textThompson, Joseph Andrew. "Thermomechanical behaviour of plasma-sprayed thermal barrier coatings." Thesis, University of Cambridge, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.621757.
Full textAhmer, Zeeshan. "An investigation on thermomechanical behaviour of a tool steel X38CrMoV5." Paris, ENMP, 2011. http://www.theses.fr/2011ENMP0075.
Full textHot work tool steel X38CrMoV5-47HRC is mainly used in industrial manufacturing processes such as high pressure die casting, hot Forging, stamping and rolling etc. The tools should comprise high fatigue strength as well as high toughness to defy thermal and mechanical shocks. The tool's Surface is principally ruined by the cyclic and progressive process under ephemeral temperature i. E. The process of non-isothermal fatigue. The appropriate constitutive laws are therefore required to predict the behaviour of material under non-isothermal conditions. This thesis depicts a contribution to predict the mechanical behaviour of X38CrMoV5-47HRC by numerical simulations using constitutive behaviour models. Assessment of the robustness and limitations of a Chaboche type thermoelastoviscoplastic model is carried out under several different test conditions starting from several uniaxial tests (LCF and TMF) to complex loading conditions with variable transient temperature range and variable amplitude of mechanical strain. After characterization of the model under the said conditions, its parameters have been re-identified in order to update the model to work under complex loading conditions. Keeping in view the model's limitations, further directions are also discussed in order to improve the model in terms of its application under severe loading conditions
De, Freitas Alves Talita. "Thermomechanical behaviour of bituminous lavers containing rigid inserts for eRoads." Thesis, Ecole centrale de Nantes, 2022. https://tel.archives-ouvertes.fr/tel-03920982.
Full textIn general, four factors need to be accurately and simply accounted for on the design of flexible pavements: traffic and loading, environmental conditions, materials properties and failure criteria (HUANG, 2004). The inclusion of charge-while-drive technologies inside road infrastructures modifies not only the common disposal of layers, but also the overall response of the structure to thermal and mechanical loadings. In order to quantify the impact of these inclusions on the performance of flexible pavements, this study proposes both numerical and experimental methodologies to measure temperature, stress and strain evolutions within electrified roads (eRoads). By means of transient 2-D FEM thermo-viscoelastic simulations, traditional and electrified road profiles were subjected to daily temperature fluctuations and to traffic.The eRoad studied contains electrified rails embedded in the bituminous wearing course, a case of particular interest due to its direct exposure to traffic and climate. The response of the structures was analysed and compared to admissible values commonly assessed to predict distresses. In laboratory, a thermal test was proposed to evaluate eRoad specimens undergoing warm and cold cycles by means of Digital Image Correlation (DIC) technique. The strain fields measured numerically and experimentally lead to the same conclusion: the rigid inserts generate additional strain along the interface of the charging unit and the bituminous layer solely due to daily temperature fluctuations. The thermos-viscoelastic model proposed and the experimental set-up have a great potential to assess innovative pavement profiles (inductive and conductive eRoads)
Nehr, Jonas Christian. "Damping and Thermomechanical behaviour of CFRP laminates modified with rubbery nanofibers." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2020. http://amslaurea.unibo.it/21702/.
Full textNogales, Tenorio Sergio. "Numerical simulation of the thermal and thermomechanical behaviour of metal matrix composites /." Düsseldorf : VDI-Verl, 2008. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=017035682&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
Full textTsoi, Kelly Ann. "Thermomechanical and Transformational Behaviour and Applications of Shape Memory Alloys and their Composites." University of Sydney. Aerospace, Mechanical and Mechatronic Engineering, 2003. http://hdl.handle.net/2123/496.
Full textDelhelay, Davinder Singh. "Nonlinear finite element analysis of the coupled thermomechanical behaviour of turbine disc assemblies." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0001/MQ46072.pdf.
Full textTsoi, Kelly Ann. "Thermomechanical and Transformational Behaviour and Applications of Shape Memory Alloys and their Composites." Thesis, The University of Sydney, 2002. http://hdl.handle.net/2123/496.
Full textOrsetti, Rossi Pedro Luis. "Effects of multipass deformation on the recrystallisation behaviour of commercial aluminium alloys during thermomechanical processing." Thesis, University of Sheffield, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.307946.
Full textRangasamy, Mahendren Sharan Raj. "Thermomechanical behaviour of multi-cracked brittle media taking into account unilateral effects : theoretical and numerical approaches." Thesis, Toulouse, INPT, 2020. http://www.theses.fr/2020INPT0070.
Full textMicromechanical and numerical methods are explored to predict the effective thermal and thermoelastic properties of a microcracked media. The effective properties are given in 2D and3D. In this thesis, special attention is paid to the anisotropy, induced by the orientation of the cracks and the unilateral effect related to the opening and closing of the cracks. The cracks aremodelled as ellipsoidal inclusions. The open cracks are considered to have no stiffness and to be thermally insulating, whereas the closed cracks are represented by a fictitious isotropic material.The theoretical approach takes advantage of various homogenization schemes and bounds to derive closed-form expressions of effective properties. The numerical approach considers finiteelement modelling and is based on the same geometry and properties of cracks as in the theory. Finally, results are compared to demonstrate the consistency between the two approaches
Forton, Andrei-Roman. "Thermomechanical behaviour of bituminous materials including RAP and rejuvenator and environmental impact of their fabrication process." Electronic Thesis or Diss., Lyon, 2021. http://www.theses.fr/2021LYSET005.
Full textThe study presented in this thesis has been carried out within a collaboration between Politehnica University Timisoara (UPT) from Romania and Université de Lyon/École Nationale des Travaux Publics de l'État (ENTPE), laboratory LTDS from France. The objectives are, i) the characterization of the thermomechanical performances of binder blends and bituminous mixtures produced with Reclaimed Asphalt Pavement (RAP) and rejuvenator and, ii) the investigation of the potential environmental impact related to the production of a mixture containing different amounts of RAP material and rejuvenator. Therefore, comprehensive experimental investigations were performed on binders and mixtures. All tests on binders and mixtures were performed in the Road Laboratory from UPT, together with the environmental impact assessment. On the other hand, the analyses, estimations and predictions of most parameters/characteristics of binders and mixtures were performed at ENTPE. The study on binders focused on the properties of different binder blends produced by mixing one type of fresh binder (a straight run 50/70 pen. grade), a RAP-extracted binder and a rejuvenator of vegetal origin. The study on mixtures focused on the investigation on 13 bituminous mixtures
Gong, Peng. "The precipitation behaviour and the formation of deformation induced ferrite during a new type of thermomechanical processing." Thesis, University of Sheffield, 2016. http://etheses.whiterose.ac.uk/12677/.
Full textWärner, Hugo. "High-Temperature Fatigue Behaviour of Austenitic Stainless Steel : Influence of Ageing on Thermomechanical Fatigue and Creep-Fatigue Interaction." Licentiate thesis, Linköpings universitet, Konstruktionsmaterial, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-153100.
Full textUrbina, Pons Cristina. "Improvement of the one-way and two-way shape memory effects in ti-ni shape memory alloys by thermomechanical treatments." Doctoral thesis, Universitat Rovira i Virgili, 2011. http://hdl.handle.net/10803/37358.
Full textLas transformaciones de fase en aleaciones de NiTi son altamente dependientes de la composición de la aleación, así como de la historia térmica y mecánica previa al uso de la SMA. El objetivo principal de esta tesis es establecer los vínculos existentes entre los cambios producidos en las transformaciones de fase por procesos termomecánicos y las propiedades funcionales en aleaciones con memoria de forma de Ti-Ni, tal que nos permita hallar los procesos termomecánicos más adecuados que proporcionen una mejora substancial en las propiedades funcionales de estas aleaciones. La determinación de estas relaciones, prestando especial atención a la fase-R, nos debe proporcionar las claves para incrementar las propiedades de memoria de forma y doble memoria de forma. Para la consecución de este objetivo se han usado diferentes técnicas de caracterización experimental: variación de la resistividad eléctrica con la temperatura (ER), difractometría de rayos X (DRX), ensayos de tracción isotérmicos, ciclados térmicos a tensión constante y ciclados térmicos a tensión nula. A través del estudio exhaustivo de las transformaciones de fase, se ha aportado una nueva interpretación de las curvas de resistividad para el cálculo de las temperaturas de transformación, se ha determinado la influencia de la fase-R en las propiedades funcionales de las SMA y se han mejorado substancialmente las propiedades de memoria simple y doble memoria de forma mediante procesos térmicos que evitan deformaciones permanentes antes del uso de la aleación.
Les transformacions de fase en aliatges de NiTi són altament dependents de la composició de l'aliatge, així com de la història tèrmica i mecànica prèvia a l'ús de la SMA. L'objectiu principal d'aquesta tesi és establir els vincles existents entre els canvis produïts en les transformacions de fase per processos termomecànics i les propietats funcionals en aliatges amb memòria de forma de Ti-Ni, tal que ens permeti trobar els processos termomecànics més adequats que proporcionin una millora substancial en les propietats funcionals d'aquests aliatges. La determinació d'aquestes relacions, prestant especial atenció a la fase-R, ens ha de proporcionar les claus per incrementar les propietats de memòria de forma i doble memòria de forma. Per a la consecució d'aquest objectiu s'han usat diferents tècniques de caracterització experimental: variació de la resistivitat elèctrica amb la temperatura (ER), difractometria de raigs X (DRX), assaigs de tracció isotèrmics, ciclats tèrmics a tensió constant i ciclats tèrmics a tensió nula. A través de l'estudi exhaustiu de les transformacions de fase, s'ha aportat una nova interpretació de les corbes de resistivitat per al càlcul de les temperatures de transformació, s'ha determinat la influència de la fase-R en les propietats funcionals de les SMA i s'han millorat substancialment les propietats de memòria simple i doble memòria de forma mitjançant processos tèrmics que eviten deformacions permanents abans de l'ús de l'aliatge.
Zivelonghi, Alessandro Verfasser], Hans-Harald [Akademischer Betreuer] [Bolt, Horst [Akademischer Betreuer] Baier, and Jeong-Ha [Akademischer Betreuer] You. "Thermomechanical Behaviour of Two Heterogeneous Tungsten Materials via 2D and 3D Image-Based FEM / Alessandro Zivelonghi. Gutachter: Hans-Harald Bolt ; Horst Baier. Betreuer: Jeong-Ha You." München : Universitätsbibliothek der TU München, 2011. http://d-nb.info/101580473X/34.
Full textAl-Sibahy, Adnan Flayih Hassan. "Thermo-mechanical behaviour of a novel lightweight concrete and its application in masonry walls." Thesis, University of Manchester, 2012. https://www.research.manchester.ac.uk/portal/en/theses/thermomechanical-behaviour-of-a-novel-lightweight-concrete-and-its-applicationin-masonry-walls(a803fcb4-a33c-4594-8622-87e565a7ceb4).html.
Full textBaumard, Théo. "Modelling the influence of infrared preheating and temperature uniformity in forming of powder-impregnated thermoplastic composites Experimental characterization and modeling of the temperature and rate-dependent shear behaviour of powder-impregnated glass fiber/PA66 woven semipregs." Thesis, Ecole nationale des Mines d'Albi-Carmaux, 2019. http://www.theses.fr/2019EMAC0010.
Full textNon-isothermal thermoforming of thermoplastic composites, in which a preconsolidated blank is heated above the melting temperature of the matrix before being formed in a press, is a process well adapted to the high production rates of automotive structural parts, allowing for cycle times < 1 min. Numerical tools to predict the apparition of manufacturing-induced defects based on the process parameters used are of an obvious industrial interest to avoid relying on a cost and time intensive trial-and-error approach. This thesis focused on the development of a comprehensive simulation of the forming of powder-impregnated PA66/glass composites, modelling explicitly the infrared preheating step to investigate the effect of temperature homogeneity on shape defects. The thermophysical and optical properties of the material were characterized experimentally at two levels of consolidation, and as a function of temperature when relevant. The structure of the non-consolidated material leads to a less uniform heating, compared to preconsolidated blanks. A finite element model based on the radiosity method to compute the radiative heat transfer was used to simulate the preheating step; this approach was validated against experimental results from a custom-built infrared oven. The model has been used to investigate the effect of blank sag on temperature distribution, and an optimization method to determine the oven parameters based on a desired temperature field has been presented. The mechanical behaviour of the woven composite during forming was modelled with a hypoelastic continuum approach, implemented in Abaqus/Explicit. The model parameters were determined from experimental tensile tests and in-plane shear tests at various temperatures and shear rates. Non-isothermal simulations of the forming of hemispherical parts were conducted, using the temperature field predicted from the preheating simulation as an input, and showed good agreement with that observed on parts formed on a lab-scale thermoforming setup
Julien, Renaud. "Comportement thermomécanique et évolution microstructurale d'un alliage Ti-6Al-4V forgé α+β, durant la trempe : expérimentations, analyses et modélisation." Thesis, Ecole nationale des Mines d'Albi-Carmaux, 2017. http://www.theses.fr/2017EMAC0001/document.
Full textThis research is part of the TiMaS project (Titanium Machining and Simulation). The main goal of this project is to develop an analysis and optimization tool of the global production process to control and assess the generation of residual stresses for titanium alloys structures parts. Residual stresses can be generated during thermal and mechanical treatment quenching steps. The main goal of this work is to study the mechanical behaviour and the microstructural evolution of Ti-6Al-4V alloy, induce by quenching from the α+β phase field, and incorporate these results in a modelling approach. For this purpose, a new experimental facility, using conventional hydraulic testing machine and induction heating, was developed to investigate the mechanical behaviour of Ti-6Al-4V alloy under different thermal and mechanical loads. This experiment has permitted to realise tensile/relaxation/tensile tests. Furthermore, an image analysis protocol was developed to study fraction of α and β phases and αII lamellae thickness. Microstructural observations can explain some aspects of the material hardening during quenching. Two mechanical behaviour models were proposed to assess the mechanical behaviour of the Ti-6Al-4V alloy. The first one is an elasto-visco-plastic model with isotropic hardening that taking account of the static recovery. It can predict the mechanical behaviour under different quenching rates. The second one is a non-unified model based on a phases mixing law. It permits a better assessment of the mechanical behaviour and allows the modelling of the yield point phenomenon by using mobile dislocations motion
Michel, Claire. "Etude des comportements thermomécaniques et à l'oxydation de réfractaires à base de SiC et à liaison nitrurée employés dans les Unités de Valorisation Energétique d'Ordures Ménagères (U.V.E.O.M.)." Thesis, Toulouse, INPT, 2011. http://www.theses.fr/2011INPT0013/document.
Full textIn this work, the microstructure and the thermomechanical behaviour of two SiC-based refractories are studied.In waste-to-energy plants, these materials are subjected to severe sollicitations such as thermal gradients, chemical composition gradients and corrosion. SiC-Si3N4 and SiC-SiAlON refractories are composed by SiC agregates bonded with silicon nitride based phases. A complex porosity network characterises the bonding phase. Its microstructure is analysed with Scanning Electron Microscopy (SEM). The thermomechanical behaviour of each refractory is characterised with 4-points bending tests and ultrasonic pulse echo measurement of the Young's modulus. During the running of waste-to-energy plants, refractories are exposed to oxidation phenomenons. They are more critical with an increase of a water content in the air. Thus, the oxidation behaviour is studied between 800°C and 1200°C under dry air, ambiant air and humid air. The microstructural evolutions due to oxidation are influenced by the porosity network, which leads to two oxidation stages depending on temperature level and environnemental conditions. Thermomechanical behaviour is also determined for each oxidation stage. This characterisation approach permits to establish relationships between the thermomechanical behaviour and the microstructural evolutions during oxidation. Phenomenological modellings are presented. Finally, thermal treatments are proposed in order to improve the durability of SiC-Si3N4 and SiC-SiAlON refractories in waste-toenergy plants
Sahli, Mehdi. "Simulation and modelling of thermal and mechanical behaviour of silicon photovoltaic panels under nominal and real-time conditions." Thesis, Strasbourg, 2019. http://www.theses.fr/2019STRAD036.
Full textThe work presented in this thesis deals with the development of a numerical multi-physics model, designed to study the optical, electrical and thermal behaviour of a photovoltaic module. The optical behaviour was evaluated using stochastic modelling based on Markov chains, whereas the electrical behaviour was drawn specifically for Silicon based photovoltaic panels using numerical optimization methods. The thermal behaviour was developed in 1D over the thickness of the module, and the multi-physics module was weakly coupled in MATLAB. The behaviour of commercial panels under nominal operation conditions was validated using data declared by the manufacturers. This model was used to perform a parametric study on the effect of solar irradiances in steady state. It was also validated for real use conditions by comparing it to experimental temperature and electrical power output. A thermomechanical study in 2D in ABAQUS/CAE based in the multi-physics model was carried out in nominal operating conditions, as well as in fatigue thermal cycling according to the IEC 61215 Standard to predict the stresses that are imposed on the panel
Yu, Kai. "Thermomechanical behaviors of active network polymers." Diss., Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/53896.
Full textWang, Yunning. "Etude et modélisation de l'effet du revenu sur les évolutions des microstructures, du comportement thermomécanique et des contraintes résiduelles de trempe." Thesis, Vandoeuvre-les-Nancy, INPL, 2006. http://www.theses.fr/2006INPL047N/document.
Full textThe relaxation of the residual stress during the tempering process is strongly related to the evolutions of the microstructure and thermomechanical properties. Thus, the simulation of the evolution of residual stresses requests the coupling of the temperature field, the phase transformations and the stress and strain evolutions all along the process. In this work, firstly, a metallurgical model has been developed to describe the tempering kinetics: nucleation, growth (or dissolution) and coarsening of the epsilon carbide and the cementite. This model allows to predict the evolutions of the matrix composition, the type, size and distribution of the precipitates during the tempering of martensite for low and middle alloyed steels. Secondly, based on the microstructure parameters calculated by the metallurgical model, a thermomechanical model has been also developed to predict the evolution of the flow stress of tempered martensite. The thermomechanical model not only takes into account the different hardening mechanisms (solution hardening, precipitate hardening and the dislocation hardening), but also the effect of deformation temperature. An experimental validation of the two models has been performed for a 80MnCr5 steel using the results obtained by electron transmission microscopy and thermomechanical dilatometry. Finally, the metallurgical model and the thermomechanical model have been implemented into the finite element calculation software ZeBuLoN to simulate the evolution of internal stress during the quenching and tempering process. A first analysis of the stress relaxation during tempering has been performed
Raude, Simon. "Prise en compte des sollicitations thermiques sur les comportements instantané et différé des géomatériaux." Thesis, Université de Lorraine, 2015. http://www.theses.fr/2015LORR0028/document.
Full textThe effect of temperature on the behaviour of geomaterials is a crucial issue in geotechnical and underground engineering. The thermo-mechanical behaviour of rocks and soils contains many applications in the fields of high-level nuclear waste disposal, heat storage, geothermal structures, petroleum drilling, zones around buried high-voltage cables, bituminous materials, and geological research. In the context of nuclear waste disposal at great depths, the thermo-mechanical behaviour of Boom clay, Opalinus clay, Callovo-Oxfordian argillite and Äspö diorite has recently received special attention in Europe. Research in these areas has demonstrated that rocks and soils may suffer from changes in their mechanical properties during short-to long-term exposure to an elevated temperature. These changes include effects on the friction angle, permeability/porosity, elastic moduli, shear strength, dilatancy, softening, brittle-to-ductile transition, creep, etc... Since Prager's first works on the modelling of non-isothermal plastic deformation, many constitutive models have been developed to include these phenomena in computational inelasticity. Most models generalize the critical-state model to include the effects of temperature on the short-term behaviour of clays and rocks. However, the effect of time on the thermo-mechanical behaviour is often not coupled to the rate-independent plasticity even if the long-term behaviour appears essential for ensuring the safety and stability during the design and construction analysis in many fields, such as the storage of nuclear waste and more generally underground excavations. Thus, it appears important to combine both instantaneous and delayed thermo-mechanical effects to obtain appropriate constitutive equations to model such problems. In this Ph.D thesis, a unified thermo-plastic/viscoplastic constitutive model has been developed for this purpose. This model is a straightforward extension of the unified elasto-plastic/viscoplastic L&K constitutive model which was developed in previous Ph.D works. The updated thermo-mechanical model includes the evolutions of the two yield limits and the fluidity coefficient with temperature. The model was validated under several thermo-mechanical conditions on clayey rocks. The typical features of the thermo-mechanical behaviour of geomaterials were well reproduced. The numerical predictions of the triaxial compression tests and creep tests clearly indicate that the model can predict the overall behaviour of geomaterials under deviatoric and non-isothermal stress paths
Hadj, kacem Yosra. "Synthèse, caractérisation et propriétés des oligoesters et composites sulfonés biosourcés." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSEI044/document.
Full textThe research conducted in this thesis was achieved in the context of vegetal biomass valorization. It aims to develop a new family of aliphatic oligoesters from biobased monomers and incorporating into their structure sulfonated groups. This choice is justified by the following three considerations. (i) This is a contribution to the valorization of vegetal biomass. (ii) The presence of sulfonated units in the structure of this type of polymers gives them specific physicochemical properties favoring their use in various industrial sectors. (iii) These oligoesters can be subsequently used for the preparation of poly (ester-urethane) networks and ionic liquid-based composites with potentially interesting thermomechanical properties and a great tendency towards hydrolytic degradation
PAIVA, ALBERTO. "MODELING OF THERMOMECHANICAL BEHAVIOR OF SHAPE MEMORY ALLOYS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2004. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=4942@1.
Full textO estudo de materiais inteligentes tem instigado várias aplicações nas mais diversas áreas do conhecimento (da área médica à industria aeroespacial). Os materiais mais utilizados em estruturas inteligentes são as ligas com memória de forma, as cerâmicas piezoelétricas, os materiais magneto-estrictivos e os fluidos eletro- reológicos. Nas últimas décadas, as ligas com memória de forma vêm recebendo atenção especial, sendo utilizadas principalmente como sensores ou atuadores. Existe uma gama de fenômenos associados a estas ligas que podem ser explorados. Visando uma análise mais precisa do comportamento destes materiais, tem se tornado cada vez maior o interesse no desenvolvimento de modelos matemáticos capazes de descrevê-los de maneira adequada, permitindo explorar todo o seu potencial. O objetivo deste trabalho é propor um modelo constitutivo unidimensional que considera quatro variantes de microconstituintes (austenita, martensita induzida por temperatura, martensita induzida por tensão trativa e martensita induzida por tensão compressiva) e diferentes propriedades para cada fase. O efeito das deformações induzidas por temperatura é incluído na formulação. O modelo contempla ainda o efeito das deformações plásticas e o acoplamento entre os fenômenos de plasticidade e transformação de fase. Além disso, são introduzidas modificações na formulação que permitem o alargamento do laço de histerese da curva tensão-deformação, fornecendo resultados mais coerentes com dados experimentais. Por fim, incorpora-se a assimetria no comportamento tração-compressão. A validação do modelo é obtida comparando os resultados numéricos obtidos através do modelo com resultados experimentais encontrados na literatura para ensaios de tração a diferentes temperaturas e para a assimetria no comportamento tração- compressão.
The study of intelligent materials has instigated many applications within the various knowledge areas (from medical field to aerospace industry). The most used materials in intelligent structures are the shape memory alloys (SMA), the piezoelectric ceramics, the magnetostrictive materials and the electrorheological fluids. In the last decades, SMAs have received special attention, being mainly used as sensors or actuators. There is a number of phenomena related to these alloys that can be explored. Aiming a more precise analysis of SMA behavior, the interest on the development of mathematical models capable of describing these phenomena properly has grown, allowing to explore all their potential. The aim of this work is to propose a unidimensional constitutive model which considers four microconstituent variants (austenite, martensite induced by temperature, martensite induced by tensile loading and martensite induced by compressive loading) and different material properties for each phase. The effect of thermal strains is included in the formulation. The model considers the effect of plastic strains and the plastic-phase transformation coupling. Besides, some changes are introduced in the formulation in order to enlarge the stress-strain hysteresis loop, resulting in better agreements with experimental data. Eventually, the tensioncompression asymmetry is incorporated. The model validation is obtained through the comparison between the numerical results given by the model and experimental results found in the literature for tensile tests at different temperatures and for tension- compression asymmetry.
Niel, Dimitri. "Etude du comportement thermomécanique de paliers à roulements pour une application hautes vitesses." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSEI007/document.
Full textRolling Element Bearing (REB) is an essential component in mechanical transmission to reduce friction between rotating parts. Now, with the development of electrical motor in mechanical industry, REBs may work at very high rotation speed. It leads to an increase of REB power losses and temperatures. Theses power losses are strongly coupled with the REB thermal behaviour. The oil temperature has a significant impact on the kinematic viscosity which in turn affects the REB power losses. Based on thermal network approach, an intermediate model is developed in this study. This new model allows obtaining lumped information (temperature of rings) with a minimum of input data (REB external geometry and operating condition only) and by using global power loss models. This intermediate model is developed for angular contact ball bearing and deep groove ball bearing under oil jet lubrication for high speed application. Experimental data are required to validate this new approach. That why, a modular test rig is designed to obtain information on the REB thermomechanical behaviour. The new test rig developed in this study is dedicated to a wide range of REB dimensions and for different operating conditions. For the first test, a deep groove ball bearing under oil jet lubrication is studied for high speed application ((N.dm) product is higher than one million.)
Voirin, Thibaut. "Etude du comportement mécanique et de l’endommagement des composites C/C à basses et hautes températures." Thesis, Lyon, 2021. http://www.theses.fr/2021LYSEI008.
Full textCarbon/Carbon composites are used in aeronautics and space industries for their excellent thermomechanical properties, from room temperature to very high temperatures (up to 3000°C). Nevertheless, these properties and their evolution at elevated temperatures are not known well enough, specifically for braking-like solicitations such as plane braking or motorsport braking.The main objectives of this work was to study the mechanical behavior of this composite under mechanical solicitations that may occur during a braking situation. Thereby, compressive and shear behavior were studied in particular, in order to determine the evolution of the damage mechanisms depending on the temperature for these loading modes. In order to lead this study successfully, various experimental aspects have been approached, such as sample geometry, as well as measurements issues due to the mechanical testing at high temperatures. This is how original mechanical testing of the interlaminar shear behavior have been performed. Concurrently with these tests, the material microstructure has been studied in-situ and post-mortem with a multi-scale approach (at ply level, at yarn level and at fiber level inside the strands). The evolution of the mechanical properties has been linked to the microstructure evolution for the different loading modes (Z-compression, XY-compression and interlaminar shear) in order to propose damage scenario of the material as a function of the temperature. This approach allowed us to understand the major role of the thermal differential dilatations of the yarn on the shrinking of the needles for temperatures up to 1500°C. For temperatures higher than 1500°C, plasticity effects have been identified
Lin, Brian E. "Stucture and thermomechanical behavior of nitipt shape memory alloy wires." Thesis, Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/28233.
Full textRittenhouse, Joseph Anderson. "Mechanics and Fracture Behavior of Thermomechanical Bonds in Nonwoven Fabric." Thesis, Virginia Tech, 2016. http://hdl.handle.net/10919/82520.
Full textMaster of Science
Vespa, Geremi. "Hot deformation behavior of magnesium AZ31." Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=99796.
Full textYan, Kun, and 閆琨. "Size effects on the thermo-mechanical behavior on nano-structures/ materials." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B41290513.
Full textZhang, Hongyan. "Numerical and analytical predictions of thermomechanical behavior of metal matrix composites /." The Ohio State University, 1991. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487759436328003.
Full textKupkovits, Robert Anthony. "Thermomechanical fatigue behavior of the directionally-solidified nickel-base superalloy CM247LC." Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/28160.
Full textCommittee Chair: Dr. Richard W. Neu; Committee Member: Dr. David L. McDowell; Committee Member: Dr. W. Steven Johnson.
Kozak, Karolina. "Influence of elaboration conditions on the thermomechanical behavior of MAX phases." Thesis, Limoges, 2019. http://www.theses.fr/2019LIMO0047/document.
Full textMAX phases are ternary carbide and/or nitride with a great potential in various application. This study concerned two MAX phase compounds, namely Ti3SiC2 and Ti2AlC, which are on the most studied among all known MAX phases. The first part dealt with materials elaboration which includes both synthesis and sintering stages. The objective was to obtain a variety of materials with different microstructural features, i.e. phase composition and grain size. For this purpose, both commercial and SHS-derived powders were densified with two pressure-assisted sintering technique, i.e. SPS and HP. The second part of work was devoted to deeper understanding of the influence of phase composition and grain size to thermomechanical behavior of MAX phases. More information was provided when two experimental techniques, four-point bending and AE monitoring, were coupled together with post-mortem SEM observations. The developed experimental approach based on comparison of mechanical responses of Ti3SiC2 (MAX phase and secondary phases) and Ti2AlC (containing only MAX phases) compounds, is implemented to investigate the induced deformation and damage mechanisms. It was shown that higher quantity of MAX phases in the material improves flexural strength with corresponding more pronounce nonlinear behavior and high dissipated energy. When MAX phase grains are coarser the mechanical strength lowers but the nonlinear part becomes more significative, which results in higher values of dissipated energy. It was also shown that the secondary phases and the grain size impact the way in which the damage is accumulated within the sample. AE data provided more information on possible damage mechanisms and their chronology leading to hysteretic behavior of MAX phases. The last part has shown that the BPTT for Ti3SiC2 is ≈1200˚C and the grain size of MAX phases lowers this BPTT
Khalfallah, Moussa. "Etude expérimentale et modélisation numérique du comportement thermomécanique d’un sandwich agrocomposite à base de fibres longues de lin." Thesis, Reims, 2015. http://www.theses.fr/2015REIMS003.
Full textTo reduce waste and CO2 emissions, car manufacturers use more and more new bio-sourced materials to lighten vehicles and reduce fuel consumption. In this context, this thesis aimed at processing a lightweight sandwich panel reinforced by long flax fibers for automotive semi-structural applications.In addition to the literature state of the art, the work is divided into three parts: the material processing, characterization and modeling of the mechanical behavior of the sandwich panel. The composite skins are reinforced by a new reinforcing material "Flaxtape", which is a veil of long unidirectional flaxfibers withouth any weft spinning. The matrix is an aqueous thermosetting resin with a very short cure time and good processability. The composite skins and derived sandwich panels are processed by a thermocompression technique respecting industrial production cycles. Thermomechanical and physicochemical characterizations are used to understand and optimize the parameters involved in their development (cooking cycle, temperature, drying, densification, fiber volume fraction, degree of crosslinking and stacking sequence). Our results highlight good specific mechanical properties of the sandwich panels at different temperatures.Furthermore, the Flaxpreg sandwich panel has been used for the achievement of a vehicle compartment floor. Numerical modeling of the mechanical behavior of the sandwich panel was used to predict the sandwich panel mechanical response at different positions in the trunk. To simplify the geometry of the sandwich panel and reduce the computation time, an analytical model of the homogenized honeycomb was used in this study
Hassanzadegan, Alireza [Verfasser], and Uwe [Akademischer Betreuer] Tröger. "Thermomechanical and poromechanical behavior of Flechtinger sandstone / Alireza Hassanzadegan. Betreuer: Uwe Tröger." Berlin : Universitätsbibliothek der Technischen Universität Berlin, 2013. http://d-nb.info/1033891371/34.
Full textConley, Jill Anne. "Hygro-thermo-mechanical behavior of fiber optic apparatus." Thesis, Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/17308.
Full textNingre, Corado. "Modélisation du comportement élastoplastique cyclique multiaxial par une approche multisurface dans l'espace des déformations." Thesis, Université Grenoble Alpes, 2020. http://www.theses.fr/2020GRALI053.
Full textThis work deals with the theoretical, numerical and experimental study of the elastoplastic mechanical behavior of metallic materials in complex multiaxial cyclic loadings. The elastoplastic behavior is described by a multisurface model, within the finite strain theory. This model is written in the five-dimensional Ilyushin strain space. The resulting model is capable of describing the multiaxial behavior of metallic materials, in complex cyclic loadings, in particular non-proportional, taking into account finite strain, time-independent irreversibility, cumulative second order effects (Poynting-Swift effect) and cyclic hardening. The model has been implemented in a commercial finite element calculation code, in order to produce an operational tool for calculating structures such as mechanical equipment and internal components of hydroelectric power plants (turbines, alternators, etc.). The proposed model was validated by comparison with combined tensile-torsion biaxial test results obtained on stainless steel. This model has been completed by an energy and thermodynamic analysis that allows the implementation of a relevant energy approach for the monitoring of fatigue damage. As part of this work, this approach was illustrated by the proposal of a fatigue criterion, validated by the comparison of its predictions with those of other classical fatigue criteria proposed in the literature
Sauter, Linda Xenia. "Microstructural and film thickness effects on the thermomechanical behavior of thin Au films." Stuttgart : Max-Planck-Inst. für Metallforschung, 2007. http://d-nb.info/995370753/34.
Full textReuse, Rolando. "Thermomechanical behavior of monolithic Sn-Ag-Cu solder and copper fiber reinforced solders." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2005. http://library.nps.navy.mil/uhtbin/hyperion/05Sep%5FReuse.pdf.
Full textKirka, Michael. "Thermomechanical behavior of a directionally solidified nickel-base superalloys in the aged state." Diss., Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/53458.
Full textNicholson, Douglas E. "Thermomechanical behavior of high-temperature shape memory alloy Ni-Ti-Pd-Pt actuators." Master's thesis, University of Central Florida, 2011. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4814.
Full textID: 030646204; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; Thesis (M.S.A.E.)--University of Central Florida, 2011.; Includes bibliographical references (p. 102-106).
M.S.A.E.
Masters
Mechanical and Aerospace Engineering
Engineering and Computer Science
Aerospace Engineering; Space System Design and Engineering Track
Menezes, Alexandre Jorge Rocha. "Analysis of the behavior of concrete thermomechanical of low resistance in low ages." Universidade Federal do CearÃ, 2015. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=16161.
Full textGreat works of infrastructure such as hydroelectric plants require, in it building, large concrete volumes classified as mass concrete structures. These works of power generation are strategic and fundamental for the development of a nation. However, during construction and throughout its life they may have pathological manifestations that compromise its stability. One of the most common problems in this type of structure is cracking caused by heat generated due to the exothermic reaction of cement hydration. Therefore, we had to analyze the thermal behavior of concrete, concrete with similar consistency and resistance like the concrete utilized in construction dam, and analyze how the type of cement utilized and its contents affects these parameters. In addition, we studied the evolution of compressive strength and dynamic modulus of elasticity as the cement hydrates. Finally, we compared the thermal performance of concretes produced with the results obtained from a commercial software. To carry out the experiment, concrete blocks were produced of 1,5m with cements CP II E 32 RS and CP IV 32 with consumption 241,2 kg/m and 330,0 kg/m for thermal analysis, besides cylindrical specimens for the remaining analyzes. The results showed that the thermal behavior of concrete has a small dependence on the type of cement, however the cement content affects too much this behavior, and the cement CP IV 32 showed higher thermal variations. It was also observed that the development of compressive strength is strongly dependent on the cement content, but it has low dependency on the type of cement. Computer modeling presented satisfactory results when it was compared to results of the thermal evolution blocks.
As grandes obras de infraestrutura como as centrais hidroelÃtricas requerem na sua construÃÃo grandes volumes de concreto, sendo classificadas como estruturas de concreto massa. Essas obras de geraÃÃo de energia sÃo estratÃgicas e fundamentais para o desenvolvimento de uma naÃÃo. Entretanto, durante sua construÃÃo e ao longo de sua vida Ãtil estas podem apresentar manifestaÃÃes patolÃgicas que comprometem sua estabilidade. Um dos problemas mais comuns nesse tipo de estrutura à a fissuraÃÃo causada pela energia tÃrmica gerada devido à reaÃÃo exotÃrmica de hidrataÃÃo do cimento. Diante disso, buscou-se analisar como se dà o comportamento tÃrmico de concretos utilizados para a construÃÃo de corpo de barragem, alÃm de analisar como o tipo de cimento utilizado e o seu teor afetam a variaÃÃo de temperatura da massa de concreto e os problemas causados por essa variaÃÃo. Buscou-se ainda analisar a evoluÃÃo da resistÃncia à compressÃo e do mÃdulo de elasticidade dinÃmico à medida que o cimento se hidratava. Por fim, comparou-se o comportamento tÃrmico dos concretos produzidos com os resultados obtidos por meio de um software comercial. Para a realizaÃÃo da parte experimental produziu-se blocos de concretos de 1,5 metros cÃbicos com cimentos CP II-E 32 RS e CP IV 32 com consumo de 241,2 kg/m e 330,0 kg/m para anÃlise tÃrmica, alÃm da moldagem de corpos de prova cilÃndricos para as demais anÃlises. Os resultados apontaram que o comportamento tÃrmico do concreto apresenta uma pequena dependÃncia do tipo de cimento. Entretanto, o teor de cimento afeta fortemente esse comportamento, sendo o cimento CP IV 32 o que apresentou maiores variaÃÃes tÃrmicas. Observou-se tambÃm que a evoluÃÃo da resistÃncia à compressÃo à fortemente dependente da quantidade de cimento, mas apresenta baixa dependÃncia do tipo de cimento. A modelagem computacional apresentou resultados satisfatÃrios quando comparado aos resultados da evoluÃÃo tÃrmica dos blocos produzidos.
Sauter, Linda Xenia. "Microstructural and film thickness effects on the thermomechanical behavior of thin Au films." [S.l. : s.n.], 2006. http://nbn-resolving.de/urn:nbn:de:bsz:93-opus-31632.
Full textTeng, Chong. "Variational Asymptotic Method for Unit Cell Homogenization of Thermomechanical Behavior of Composite Materials." DigitalCommons@USU, 2013. https://digitalcommons.usu.edu/etd/2048.
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