Academic literature on the topic 'Interface direct shear'
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Journal articles on the topic "Interface direct shear"
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Lee, K. M., and V. R. Manjunath. "Soil-geotextile interface friction by direct shear tests." Canadian Geotechnical Journal 37, no. 1 (February 1, 2000): 238–52. http://dx.doi.org/10.1139/t99-124.
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This paper describes large-size direct shear tests on soil-geotextile interfaces. Medium-grained, uniform sand and three varieties of woven and nonwoven geotextiles manufactured with different techniques are utilized to investigate the soil-geotextile interface friction coefficient (f*). Tests were carried out using an apparatus specifically designed for interface testing, and results were compared with those obtained from the conventional direct shear equipment. The results obtained from this study indicated that the determination of peak interface behaviour was not a trivial matter, as the results were significantly affected by the boundary and testing conditions of the testing apparatus. The residual interface behaviour was investigated by multiple reversal direct shear tests. Since the use of multiple reversal direct shear tests on the proposed apparatus can impose a high degree of shear displacement and stress uniformity on the soil-geotextile interface, a more reliable definition of the residual interface friction can be obtained. The results indicate that woven-nonwoven geotextile interfaces exhibit a significant postpeak strength loss after a number of shear cycles. In the case of woven geotextiles, this is attributed to the opening up of the filaments associated with the physical damage caused during shear, whereas for nonwoven geotextiles it is due to the pulling out or tearing of filaments.Key words: geotextile, direct shear test, interface friction coefficient, peak shear strength, residual shear strength.
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Chen, Xiaobin, Jiasheng Zhang, Yuanjie Xiao, and Jian Li. "Effect of roughness on shear behavior of red clay – concrete interface in large-scale direct shear tests." Canadian Geotechnical Journal 52, no. 8 (August 2015): 1122–35. http://dx.doi.org/10.1139/cgj-2014-0399.
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Few studies have focused on evaluating regular surface roughness and its effect on interfacial shear behavior of the red clay – concrete interface. This paper presents the results of a series of laboratory large-scale direct shear tests conducted using different types of red clay – concrete interfaces. The objective is to examine the effect of surface roughness on these types of soil–concrete interfaces. In the smooth-interface tests, the measured peak and residual shear strength values are very close to each other, with no observed shear dilation. The surface roughness is found to have a remarkable effect on the interfacial shear strength and shear behavior, with the shear strength increasing with increased surface roughness level. The shear dilation is likely to occur on rougher interfaces under lower confining pressure due to the behavior of compressed clay matrices. Owing to the clay matrix’s cohesion and friction, the interfacial shear strength on rough interfaces consists of cohesive and frictional forces between the clay and concrete surfaces. The friction angle value is observed to fluctuate between the clay’s friction angle and the smooth interface’s friction angle. This can be related to the position change of the shear failure slip plane. The confining pressure and surface roughness could change the shear failure plane’s position on the interface. Furthermore, the red clay – structure interface is usually known as the weakest part in the mechanical safety assessment.
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Wang, Jun, Meng-Jie Ying, Fei-Yu Liu, Hong-Tao Fu, Jun-Feng Ni, and Jing Shi. "Effect of Particle-Size Gradation on Coarse Sand-Geotextile Interface Response in Cyclic and Postcyclic Direct Shear Test." Advances in Civil Engineering 2020 (September 3, 2020): 1–11. http://dx.doi.org/10.1155/2020/1323296.
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In order to investigate the influence of sand particle-size gradation on cyclic and postcyclic shear strength behaviour on sand-geotextile interfaces, a series of monotonic direct shear (MDS), cyclic direct shear (CDS), and postcyclic direct shear (PCDS) tests were performed using a large-scale direct shear apparatus. The influence of cyclic shear history on the direct shear behaviour of the interface was studied. The results indicated that cyclic shear stress degradation occurred at the sand-geotextile interface. Shear volumetric contraction induced by the cyclic direct shear increased with the increase in cycle number. The lowest final contraction value was observed in discontinuously graded sand. In the MDS tests, there were great differences in interface shear strength due to the different particle-size gradations, whereas the differences between shear volumes were negligible. In the PCDS tests, the shear stress-displacement curves exhibited postpeak stress hardening behaviour for different particle-size gradations, and differences in shear volumes were detected. The well-graded sand-geotextile interface had a higher value of shear stiffness and a higher damping ratio relative to the other interfaces. Postcyclic shear stress degradation was observed for the discontinuously graded sand-geotextile interface.
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Hamid, Tariq B., and Gerald A. Miller. "Shear strength of unsaturated soil interfaces." Canadian Geotechnical Journal 46, no. 5 (May 2009): 595–606. http://dx.doi.org/10.1139/t09-002.
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Unsaturated soil interfaces exist where unsaturated soil is in contact with structures such as foundations, retaining walls, and buried pipes. The unsaturated soil interface can be defined as a layer of unsaturated soil through which stresses are transferred from soil to structure and vice versa. In this paper, the shearing behavior of unsaturated soil interfaces is examined using results of interface direct shear tests conducted on a low-plasticity fine-grained soil. A conventional direct shear test device was modified to conduct direct shear interface tests using matric suction control. Further, the results were used to define failure envelopes for unsaturated soil interfaces having smooth and rough counterfaces. Results of this study indicate that matric suction contributes to the peak shear strength of unsaturated interfaces; however, postpeak shear strength did not appear to vary with changes in matric suction. Variations in net normal stress affected both peak and postpeak shear strength. Failure envelopes developed using the soil-water characteristic curve (SWCC) appeared to capture the nonlinear influence of matric suction on shear strength of soil and interfaces.
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Mortara, Giuseppe, Antonio Mangiola, and Vito Nicola Ghionna. "Cyclic shear stress degradation and post-cyclic behaviour from sand–steel interface direct shear tests." Canadian Geotechnical Journal 44, no. 7 (July 1, 2007): 739–52. http://dx.doi.org/10.1139/t07-019.
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The sliding interaction between sand and structural materials is involved in many geotechnical applications and is particularly important for the derivation of the shaft capacity of piles. Such interaction develops principally at the interface between the sand mass and the structural surface, and the comprehension of such interaction can be analysed through soil–structure interface tests. In particular, by using a modified version of the interface direct shear apparatus, that is, the constant normal stiffness direct shear apparatus, the friction characteristics of the interface and the role of the soil deformability on the experimental results can be studied. This paper focuses on the stress degradation occurring in these types of tests when cyclic loading is applied on sand–steel interfaces. Also, the post-cyclic response is analysed and compared to the response under monotonic conditions.Key words: interface, sand, shear stress, cyclic loading, stress degradation.
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Yin, Kexin, Jiangxin Liu, Jiaxing Lin, Andreea-Roxana Vasilescu, Khaoula Othmani, and Eugenia Di Filippo. "Interface Direct Shear Tests on JEZ-1 Mars Regolith Simulant." Applied Sciences 11, no. 15 (July 30, 2021): 7052. http://dx.doi.org/10.3390/app11157052.
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The mechanical behaviors of Martian regolith-structure interfaces are of great significance for the design of rover, development of excavation tools, and construction of infrastructure in Mars exploration. This paper presents an experimental investigation on the properties of a Martian regolith simulant (JEZ-1) through one-dimensional oedometer test, direct shear test, and interface direct shear tests between JEZ-1 and steel plates with different roughness. Oedometer result reveals that the compression and swelling indexes of the JEZ-1 are quite low, thus it is a less compressible and lower swelling soil. The cohesion and adhesion of JEZ-1 are lower than 5 kPa. The values of the internal friction angle range from 39.7° to 40.6°, and the interface friction angles are 16.7° to 36.2° for the smooth and rough interface. Furthermore, the direct shear and interface direct shear results indicate that the interface friction angles are lower than the internal friction angles of JEZ-1 and increase close to the internal friction angles with increasing interface roughness.
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Salama, Imane, and Christophe Dano. "Direct interface shear tests on Dunkirk sand." E3S Web of Conferences 92 (2019): 13003. http://dx.doi.org/10.1051/e3sconf/20199213003.
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After a field test campaign conducted in Dunkirk (north of France) on open-ended steel piles aiming to study the ageing phenomenon, laboratory scale shear tests were designed to study the behaviour of the sand-steel interface. In order to carry out this laboratory investigation, the direct interface shear apparatus was used for characterizing Dunkirk sand (in dry or unsaturated conditions with about 6% water content as in the field) consolidated on initially smooth mild steel plates at different consolidation time intervals (0, 1 and 7 days) and different consolidation stresses (50, 100, 200 and 300 kPa). The test program also included two normal boundary conditions (Constant normal load CNL and constant volume CV) so that they can be compared to the field results and determine the most approaching configuration. More, the unsaturated condition induced a corrosion of the mild steel plates, causing a layer of sand remaining glued to the plate after removing the shear box. Traces of corrosion were also observed on the lower part of the sand samples (in contact with the plate). These observations lead to the interpretation of an increase of the mechanical properties (local cohesion and increase of the friction angle). In order to follow the evolution of the corrosion for each plate, thickness measurements of the sand layer stuck on the plates were carried out.
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Suits, L. D., T. C. Sheahan, GA Miller, and TB Hamid. "Interface Direct Shear Testing of Unsaturated Soil." Geotechnical Testing Journal 30, no. 3 (2007): 13301. http://dx.doi.org/10.1520/gtj13301.
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Wang, Dong, Jian Xin Zhang, Bin Tian, and Jia Cao. "The Contrastive Research of Direct Shear Test on Different Pile-Soil Interface." Applied Mechanics and Materials 90-93 (September 2011): 1743–47. http://dx.doi.org/10.4028/www.scientific.net/amm.90-93.1743.
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In order to discuss the friction resistance properties between pile and soil, three groups of shear laboratory tests of pile-soil interface are adopted among concrete-soil , steel-soil and plastic(HDPE)-soil, and each test applies six normal stresses. The result indicates that with the growth of normal stress, the shear strength of pile-soil are increased; under the same normal stress, there is little change in frontal parts of curve with shear stress and displacement, but the rest of curve have a striking change along with the increase of normal stress; when the normal stress is less, the shear stress of different interfaces have little change; when the normal stress is greater, it shows that the shear strength of HDPE-soil interface is the greatest.
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Li, Lihua, Han Yan, Henglin Xiao, Wentao Li, and Zhangshuai Geng. "Sand- and Clay-Photocured-Geomembrane Interface Shear Characteristics Using Direct Shear Test." Sustainability 13, no. 15 (July 22, 2021): 8201. http://dx.doi.org/10.3390/su13158201.
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It is well known that geomembranes frequently and easily fail at the seams, which has been a ubiquitous problem in various applications. To avoid the failure of geomembrane at the seams, photocuring was carried out with 1~5% photoinitiator and 2% carbon black powder. This geomembrane can be sprayed and cured on the soil surface. The obtained geomembrane was then used as a barrier, separator, or reinforcement. In this study, the direct shear tests were carried out with the aim to investigate the interfacial characteristics of photocured geomembrane–clay/sand. The results show that a 2% photoinitiator has a significant effect on the impermeable layer for the photocured geomembrane–clay interface. As for the photocured geomembrane–sand interface, it is reasonable to choose a geomembrane made from a 4% photoinitiator at the boundary of the drainage layer and the impermeable layer in the landfill. In the cover system, it is reasonable to choose a 5% photoinitiator geomembrane. Moreover, as for the interface between the photocurable geomembrane and clay/sand, the friction coefficient increases initially and decreases afterward with the increase of normal stress. Furthermore, the friction angle of the interface between photocurable geomembrane and sand is larger than that of the photocurable geomembrane–clay interface. In other words, the interface between photocurable geomembrane and sand has better shear and tensile crack resistance.
Dissertations / Theses on the topic "Interface direct shear"
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Dietz, Matthew S. "Developing an holistic understanding of interface friction using sand with direct shear apparatus." Thesis, University of Bristol, 2000. http://hdl.handle.net/1983/55218bdd-b641-4365-a921-5a7ca0d475bc.
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Ross, Jason D. "Static and Dynamic Shear Strength of a Geomembrane/Geosynthetic Clay Liner Interface." The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1243545173.
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Iscimen, Mehmet. "Shearing Behavior Of Curved Interfaces." Thesis, Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/7256.
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The frictional behavior of soil-construction material interfaces is of significant importance in geotechnical engineering applications such as retaining structures, pile foundations, geosynthetic liners, and trenchless technologies. Since most failures initiate and develop on the interfaces, special attention is required to predict the capacity of these weak planes in the particular application.
Pipe-jacking and microtunneling technologies are being more widely used over the past decade and there is significant interest to predict the jacking forces and jacking distances achievable in order to achieve more efficient design and construction. This study focuses on the evaluation of the frictional characteristics and factors affecting the shear strength of pipe-soil interfaces. Eight different pipes made from fiber reinforced polymer (FRP), polycrete, steel, concrete, and vitrified clay were tested in the experimental program.
For this purpose, a new apparatus was designed to conduct conventional interface direct shear testing on pipes of different curvature. This device allows coupons cut from actual conduits and pipes to be tested in the laboratory under controlled conditions. The apparatus includes a double-wall shear box, the inner wall of which is interchangeable to allow for testing against surfaces of different curvatures. By considering a narrow width section, the circular interface of pipes was approximated with a surface along the axial direction and the boundary is defined by the inner box.
Roughness tests were performed using a stylus profilometer to quantify the surface characteristics of the individual pipes and relate these to the interface shear behavior. The surface topography showed different degrees of variability for the different pipes. To extend the range of roughness values tested and force the failure to occur in the particulate media adjacent to the interface, two artificial pipe surfaces were created using rough sandpapers.
Interface shear tests were performed using the new apparatus with air-pluviated dense specimens of Ottawa 20/30 sand. Additional tests were performed using Atlanta blasting sand to evaluate the effect of particle angularity. The effect of normal stress and relative density were also examined. The interface strength was shown to increase with surface roughness and finally reach a constant value above a certain critical roughness value, which corresponded to the internal strength of the soil itself. This represented the failure location moving from the interface into the soil adjacent to the interface. Both the strength and the shearing mechanism were thus affected by the surface topography. It was also shown that the interface shear strength was affected by particle angularity, relative density and normal stress.
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Orebowale, Patience B. "Investigating the stability of geosynthetic landfill capping systems." Thesis, Loughborough University, 2006. https://dspace.lboro.ac.uk/2134/7786.
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The use of geosynthetics in landfill construction introduces potential planes of weakness. As a result, there is a requirement to assess the stability along the soil/geosynthetic and geosynthetic/geosynthetic interfaces. Stability is governed by the shear strength along the weakest interface in the system. Repeatability interface shear strength testing of a geomembrane/geotextile interface at low normal stresses suitable for capping systems showed considerable variability of measured geosynthetic interface shear strengths, suggesting that minor factors can have a significant influence on the measured shear strength. This study demonstrates that more than one test per normal stress is necessary if a more accurate and reliable interface shear strength value is to be obtained. Carefully controlled inter-laboratory geosynthetic interface shear strength comparison tests undertaken on large direct shear devices that differ in the kinematic degrees of freedom of the top box, showed the fixed top box design to consistently over estimate the available interface shear strength compared to the vertically movable top box design. Results obtained from measurement of the normal stress on the interface during shear with use of load cells in the lower box of the fixed top box design, raise key questions on the accuracy, reliability and proper interpretation of the interface shear strength data used in landfill design calculations. Tests on the geocomposite/sand interface have shown the interface friction angle to vary with the orientation of the geocomposite's main core, in relation to the direction of shearing. Close attention needs to be paid to the onsite geocomposite placement in confined spaces and capping slope corners, as grid orientation on the slope becomes particularly important when sliding is initiated. Attempts to measure the pore water pressure during staged consolidation and shear along a clay/geomembrane interface in the large direct shear device suggest that this interface is a partial drainage path.
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Toufigh, Vahid. "Testing and Evaluation of Confined Polymer Concrete Pile with Carbon Fiber Sleeve." Diss., The University of Arizona, 2013. http://hdl.handle.net/10150/293492.
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The goal of this research is to investigate the behavior of polymer concrete confined with a carbon fiber sleeve used as a pile foundation. To evaluate the behavior of a confined polymer concrete pile in this research, four steps was considered. The first step of this investigation considered the mix design of polymer concrete, polymer concrete is a new material which is a combination of epoxy resin and aggregate. Instead of using a traditional mix of cement and water to make concrete, epoxy resin is used. Three dissimilar varieties of aggregate are mixed with different ratios in order to reach the maximum bulk density to obtain the maximum strength. After discovering the optimum ratio which gives the maximum bulk density, several samples of the aggregate are mixed with different ratios of epoxy resin. Next, the samples are investigated in a compression test to observe which ratios have the maximum strength and this ratio is used for a polymer concrete mix design to create a pile foundation. The pile is a built using a cast in place method and confined with a sleeve of carbon fiber. The second part of this investigation determined the structural mechanical properties of confined polymer concrete pile material. The unconfined and confined polymer concrete was tested in compression to determine compressive strength and stress-strain behavior. Similar tests were conducted on unconfined and confined cement concrete for comparison between these materials. Additional tension tests were conducted on unconfined polymer concrete. Then, a carbon fiber sleeve was tested in compression test to determine tensile strength and tension stress-strain behavior. After these tests, the confined polymer concrete is modeled in the computer program MATTCAD which is used to calculate the theoretical bending moment capacity and load-displacement curve. Finally, the confined polymer concrete is tested with the MTS 311 Load Frame in three point load flexure test to determine the experimentally bending moment capacity, load-displacement curve and compare with theoretical results. Confined polymer concrete was tested in one and two way cyclic loading to observe the ductility behavior of this material as laterally loaded piles and compared with cement concrete results in cyclic loading. The third part of this investigation determined the geotechnical mechanical properties of confined polymer concrete pile material. Cyclic Multi Degree of Freedom (CYMDOF) device was used to determine interface reaction and friction angle between confined polymer concrete and soil with interface shear test theory method. Furthermore, the same device was used to determine the friction angle of soil with direct shear test theory, and compare the friction angle results together. The last part of this investigation considered the behavior of different sized confined polymer concrete pile in different types of soil. A confined polymer concrete pile was modeled into PLAXIS and OPENSEES PL computer software to analysis pile in axial load and lateral load respectively. Furthermore, a cement concrete pile was modeled with similar software and conditions to compare these two materials.
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Yin, Kexin. "Influence of clay fraction on the mechanical behavior of a soil-concrete interface." Thesis, Ecole centrale de Nantes, 2021. http://www.theses.fr/2021ECDN0015.
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L’interface sol-structure est un aspect important des intéractions entre le sol et la structure car elle permet d’assurer en grande partie la stabilité de la structure concernée. Le comportement mécanique de l’interface joue un rôle significatif dans le dimensionnement des structures de génie civil et dans la prédiction de leur comportement dans le temps. L’interface entre le sol et la structure est une fine couche de sol en contact avec la structure, dans laquelle des contraintes et des déformations se développent. A notre connaissance, les travaux précédents de la littérature qui caractérisent le comportement mécanique de cette interface concernent principalement des sols types tels que sable et argile ou des matériaux naturels, en contact avec des matériaux structurels tels que le béton, le bois ou l’acier. Cependant, les sols naturels sont très complexes, en partie dû aux hétérogénéités qu’ils contiennent et à leur histoire géologique, et la réponse mécanique des sols type ne permet pas toujours de représenter celles des sols naturels, ni celle de sols intermédiaires. Le comportement mécanique de sols intermédiaires entre sable et argile a été largement étudié, cependant celui de l’interface entre ces sols et un matériau structurel n’est que peu représenté, alors que la réponse de l’interface soumise à un chargement mécanique est bien différente de celui du sol seul. De plus, à l’échelle de l’ingénieur, il y a clairement un manque d’informations sur le comportement de cette interface le long d’une fondation chargée dans ces sols intermédiaires, numériquement et expérimentalement, ceci étant en partie lié aux difficultés d’instrumentations in-situ le long des foundations. L’objectif de cette thèse est de caractériser le comportement mécanique de l’interface entre le sol et la structure pour des sols intermédiaires entre le sable et l’argile. Des mélanges artificiels de sable de silice et d’argile riche en kaolinite ont été choisis pour représenter les sols intermédiaires. La thèse est d’abord composée d’une campagne expérimentale d’essais de cisaillement direct d’interface en laboratoire, afin d’identifier le rôle de la fraction massique d’argile sur le comportement mécanique d’une interface sol-béton. Une attention particulière a été apportée sur le montage expérimental et sur la préparation optimisée des échantillons de sol. Les résultats ont ensuite été utilisés dans une campagne de modélisation à l’échelle de l’ingénieur, visant à réprésenter le comportement mécanique de l’interface autour d’un pieu chargé latéralement. Une nouvelle routine MATLAB en éléments finis a été implémentée pour modéliser le comportement de cette interface par des courbes p y. La caractérisation du comportement mécanique de l’interface sol structure pour des sols à fraction massique d’argile variable a permis de mieux mettre en lumière le rôle de la microstructure de l’interface, sur la stabilité des structures de génie civilIn geotechnical engineering, the soil-structure interface is an important aspect to take into account in soil structure interactions because it relates to the stability of the supported structure. In particular, the mechanical behaviour of the interface plays a key role in the design of civil engineering structures and their analysis over time. The interface is a thin zone of soil in contact with the structure where major stresses and strains develop in. To our knowledge, previous works on the characterization of the mechanical behaviour of the soil-structure interface mainly include typical soils (sand or clay) or natural soils, in contact with variable structural materials (concrete, steel, wood). However, natural soils are very complex, partly due to geological heterogeneities, and the mechanical response of typical soils do not always represent accurately intermediate soils between sand and clay. Previous studies on the mechanical behavior of those soils are significantly represented in the literature, especially in experimental research, however it is rather poorly documented on the interface between these soils and structural materials, whereas their response to mechanical loadings is different. Moreover, at the engineering scale, there is still a lack of understanding on how this interface behave along loaded pile within soils between sand and clay, numerically, and experimentally due to instrumentation restrictions along the pile. The objective of this thesis is to characterize the mechanical behaviour of the soil-structure interface for intermediate soils between sand and clay, both by experiments at the laboratory scale and by models at the engineering scale. Artificial mixtures of silica sand and kaolinite-rich clay are chosen to represent intermediate soils in this study. For this propose, the research is organized in a first and main experimental campaign that aims to investigate the effect of the clay content, from 0% (sand) to 100% (clay) on the mechanical behavior of a soil-concrete interface by a new interface direct shear device in the laboratory. A particular attention is given to the design of the setup, and to the investigation of four sample preparations to insure an optimize sample homogeneity. A second and numerical campaign is performed to input the results from the experimental campaign, to model the mechanical response of the interface between sand-clay soils and a lateral concrete loaded pile at the engineering scale. A new subroutine of a MATLAB finite element code is implemented to perform the numerical modelling of the interface’s response via the p-y curves. The characterization of the mechanical behaviour of the soil-structure interface at different clay and sand fractions allows to enlighten the role of soil microstructure at the soil-structure interface on the stability of civil engineering structures
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Reis, Jeselay Hemetério Cordeiro dos. "Modelo de atrito estático em interfaces de contato entre concreto e areia." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/18/18132/tde-17072006-111343/.
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Esta tese apresenta os princípios e a formulação de um modelo não-linear de atrito estático em interface de concreto areia. A hipótese básica para desenvolvimento das equações consiste na ocorrência do atrito de deslizamento (atrito verdadeiro), do atrito de rolamento (rearranjo das partículas) e da dilatância (variação de volume durante o cisalhamento). A solução analítica do modelo considera o efeito da rugosidade da superfície de contato, da curva granulométrica da areia e do seu estado de compacidade inicial. Foram realizados ensaios de cisalhamento direto com carga normal constante em interface de contato entre concreto e areia com seção de 500 mm x 500 mm com o objetivo de permitir a calibração do modelo proposto. É discutida e sugerida a incorporação da equação constitutiva desse modelo em análises de interação solo-estrutura via método dos elementos finitos. Sua aplicabilidade é demonstrada através da análise 1D e 2D de estacas de atrito executadas em areia e submetidas a carregamentos de compressãoThis thesis presents the principles and formulation underlying a concrete-sand interface nonlinear static friction model. The basic hypothesis employed in the development of the model equation takes into account the interface sliding friction (true friction), a rolling friction (particle rearrangement) and dilatancy(volume variation during shear). The model analytical solution considers the effect of roughness of the contact surface, the grain size distribution and its initial state of compactness of the sand. To calibrate the proposed model, a direct shear stress test under constant load was carried out along a 500mm x 500mm section concrete-sand interface. Furthermore, a discussion and suggestion of the inclusion of the model constitutive equation applied to the analysis of soil-structure interaction using the finite element method are presented. The applicability of the proposed model is proven through the analysis of 1-D and 2-D skin friction piles made of sand mass subjected to compression load
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CASTRO, ALESSANDRA TAVARES DE. "TILT TESTS AND DIRECT SHEAR ON SOIL-GEOSYNTHETIC INTERFACES." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2008. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=12570@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROCOORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
A aplicação de geossintéticos em obras geotécnicas vem crescendo intensamente nos últimos tempos, tornando cada vez mais importantes e necessários os estudos da resistência de interface para aplicação em projetos e obras. Em particular, tais estudos devem tratar das técnicas de ensaios de campo e de laboratório para a obtenção dos parâmetros de resistência (adesão e ângulo de atrito). Os ensaios de laboratório são utilizados com maior freqüência por serem mais acessíveis e de fácil execução. Os ensaios de campo reproduzem mais diretamente as condições das obras, mas apresentam como desvantagem o custo elevado e a dificuldade de execução. Este trabalho tem como finalidades apresentar o equipamento de ensaio utilizado e analisar os resultados de um programa em interfaces solo- geossintético. O programa experimental envolveu ensaios de rampa, cisalhamento direto convencional e cisalhamento direto inclinado em solo com granulação grosseira (brita), em contacto com as geomembranas e as geogrelhas. Os resultados foram analisados avaliando-se as influências da tensão confinante e da inserção dos geossintéticos, e comparandose os diferentes tipos de materiais e de técnicas de ensaio. A influência da tensão confinante foi estudada com base em três tensões confinantes distintas, de baixa magnitude (1,0; 1,7 e 2,4kPa). O aumento da tensão confinante implicou em um aumento, tanto do deslocamento até a ruptura quanto da resistência da interface. Este comportamento deve-se à possibilidade de rearranjo e imbricamento entre os grãos da brita. Em relação ao tipo de geossintético, a interface brita-geogrelha apresentou maior resistência do que a interface brita-geomembrana. Isto pode ser explicado em função da estrutura do geossintético, pois a geomembrana perde possui uma superfície lisa, o que favorece o deslizamento, ao contrário da geogrelha, que conta com o efeito do imbricamento do solo nas aberturas da malha.
The use of geosynthetics in geotechnical construction is growing up intensively on the last years, which make the study on interface strength more important and necessary to its application on projects and construction. Particularly, these studies should watch out field and laboratory tests in order to obtain strength parameters (adhesion and friction angle). Laboratory tests are more frequently used, due to their accessibility and easy execution. Field tests reproduce construction condition in a directly way, but have as disadvantages high cost and hard execution condition. The current research have as objectives present the test equipment used and analyze software results obtained for soil and geosynthetic interfaces. The experimental program involved ramp tests, conventional direct shear test and inclined direct shear test. This program was carried out on gravel soil in contact with two different types of geosynthetics (geomembrane and geogrids). Results were analyzed based on the influence of confining pressure and the introduction of geosynthetics, and comparing the different materials and test techniques. The confining pressure influence/importance was studied based on three different low magnitude confining pressures (1,0; 1,7 e 2,4kPa). The confining pressure increases resulted in an increase of both displacements until the failure and interface strength. This behavior could be explained due to the possibility of interlocking e between the gravel grains. Considering the geosynthetic type, gravel-geogrid interface presented higher strength than gravel- geomembrane interface. This could be explained by the structure of the geosynthetic; geomembrane has low strength due to its smooth surface, which benefits the slide. Geogrid instead, counts with the soil interlocking; effects in the mesh holes.
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Saffari-Shooshtari, Nader. "Constant normal stiffness direct shear testing of chalk-concrete interfaces." Thesis, University of Surrey, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.328819.
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Pra-ai, Suriyavut. "Essais et modélisation du cisaillement cyclique sol-struture à grand nombre de cycles. Application aux pieux." Phd thesis, Université de Grenoble, 2013. http://tel.archives-ouvertes.fr/tel-00809729.
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On présente tout d'abord une série d'essais de cisaillement direct 2D monotones et cycliques sur l'interface sable de Fontainebleau-plaque rugueuse et lisse, 'a contrainte normale constante (CNL) et à rigidité normale imposée (CNS). Le but de ces essais est de simuler la situation mécanique le long de pieux soumis à un grand nombre de cycles d'origine environnementale ou anthropique. Ces cycles (typiquement 10000) de faible amplitude (10'a 40 kPa en terme de contrainte de cisaillement) ne sont pas cens'es produire de rupture prématurée. Ces tests incluent une série de cycles d'amplitudes (successives) variées. Le problème de la perte de sable entre la boite et la plaque est trait'e avec attention. Nous avons interprété l'effet de la position du "centre des cycles" dans le plan de contraintes (variables cycliques moyennes) et de la densité initiale. Plusieurs facteurs tels que l'indice initial de densité (ID0), la contrainte normale cyclique moyenne (_n cm0), le niveau initial moyen de contrainte de cisaillement (_cm0), l'amplitude cyclique réduite (__) et la rigidité normale imposée (k qui dans cette thèse, va de 1000 'a 5000 kPa/mm), influencent les déplacements relatifs cycliques moyens normal ([u]cm) et tangentiel [w]cm) et sont pris en considération.On observe soit de la dilatance, soit de la contractance en accord avec l'état caractéristique développé par Luong. L'influence du chemin de contrainte (CNL ou CNS) est également analysée. Un modèle phénoménologique et analytique de comportement d'interface sur chemins cycliques CNL est propos'e. C'est également le cas pour le comportement monotone sur chemins oedométrique et CNL, la variable de mémoire unique étant la densité d'interface (sous contrainte) ou le déplacement relatif normal. Cette formulation permet de traiter, par incréments analytiques finis, les chemins comportant une variation d'amplitude cyclique, et les chemins CNS, ce qui introduit la notion de nombre de cycles équivalent. On notera que les chemins CNS sont toujours contractants. Ces essais sont utilisés pour aborder la simulation par éléments finis, avec le logiciel Plaxis, selon une approche de pseudo-viscoplasticité, le nombre de cycles tenant lieu de temps fictif. L'essai de cisaillement monotone'a la boite est modélisé en densités faible et forte, ainsi que deux essais de pieux modèles centrifugés, l'un en traction, l'autre en compression. Des recommandations sont proposées pour le calcul courant des pieux sous sollicitations cycliques. Cette thèse a été soutenue par l'ANR SOLCYP et le programme national " recherches sur le comportement des pieux soumis à des sollicitations cycliques".
Books on the topic "Interface direct shear"
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United States. Bureau of Reclamation. Denver Office. Materials Engineering Branch., ed. Direct shear tests used in soil-geomembrane interface friction studies. Denver, Colo: Materials Engineering Branch, Research and Laboratory Services Division, Denver Office, U.S. Bureau of Reclamation, 1994.
Find full textBook chapters on the topic "Interface direct shear"
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Jin, Zihao, Qi Yang, Junzhe Liu, and Chen Chen. "Concrete-Sand Interface in Direct Shear Tests." In Springer Series in Geomechanics and Geoengineering, 542–45. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-97112-4_121.
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An, Feng-Chen, Shuang-Yin Cao, Jin-Long Pan, and Qian Ge. "Investigation on Fracture Behavior of FRP-Concrete Interface under Direct Shear." In Advances in FRP Composites in Civil Engineering, 499–503. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-17487-2_107.
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Ebrahimian, B., and E. Bauer. "Investigation of Direct Shear Interface Test Using Micro-polar Continuum Approach." In Springer Series in Geomechanics and Geoengineering, 143–48. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-13506-9_21.
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Bilke, Lars, Thomas Fischer, Dmitri Naumov, Daniel Pötschke, Karsten Rink, Amir Shoarian Sattari, Patrick Schmidt, Wenqing Wang, and Keita Yoshioka. "Code Descriptions." In GeomInt–Mechanical Integrity of Host Rocks, 243–54. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-61909-1_7.
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AbstractThe FFS method (see Sect. 10.1007/978-3-030-61909-1_3) was developed to simulate direct shear tests. To provide a tool for the project work and get things easier done a graphical user interface (GUI) was also created. The GUI simply calls all necessary functions by letting the user either fill form fields or choose input files from the working folder. The rock parameters and the conditions of the direct shear test with the normal stress levels and shear displacements have to be selected. If an experiment is simulated the lab results can be selected as a text file so a visual comparison is possible. The geometry has to be loaded as a point cloud or an artificial surface can be generated. With small modifications the code can do multiple executions using artificial surfaces.
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Mouzannar, Hussein, M. Bost, P. Joffrin, C. Pruvost, F. Rojat, J. Blache, A. Houel, et al. "Instrumentation of Large Scale Direct Shear Test to Study the Progressive Failure of Concrete/Rock Interface." In RILEM Bookseries, 649–55. Dordrecht: Springer Netherlands, 2016. http://dx.doi.org/10.1007/978-94-024-0867-6_91.
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Markou, Ioannis N. "Direct Shear Testing of Sand – Geotextile Interfaces." In Sustainable Civil Infrastructures, 1–12. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-63570-5_1.
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Meyer, V., R. Dyvik, and D. White. "Direct shear interface tests for pipe-soil interaction assessment." In Frontiers in Offshore Geotechnics III, 423–28. CRC Press, 2015. http://dx.doi.org/10.1201/b18442-48.
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Nicola Ghionna, Vito, Giuseppe Mortara, and Giovanni Paolo Vita. "Sand–structure interface behaviour under cyclic loading from constant normal stiffness direct shear tests." In Deformation Characteristics of Geomaterials / Comportement Des Sols Et Des Roches Tendres. Taylor & Francis, 2003. http://dx.doi.org/10.1201/noe9058096043.ch29.
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Nishiyama, T., and T. Hasegawa. "A practical use of the finite element with an embedded interface for simulating the direct shear on brittle materials." In Computer Methods and Recent Advances in Geomechanics, 323–27. CRC Press, 2014. http://dx.doi.org/10.1201/b17435-53.
Full textConference papers on the topic "Interface direct shear"
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Amarasinghe, Ruslan S., Dharma Wijewickreme, and Hisham T. Eid. "Some Observations on Soil-Pipe Interface Shear Strength in Direct Shear Under Low Effective Normal Stresses and Large Displacements." In 2016 11th International Pipeline Conference. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/ipc2016-64100.
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Experimental work is undertaken at the University of British Columbia (UBC) to study the soil-pipe interface shear strength at levels of shear displacements and effective normal stresses typically encountered in offshore soil-pipe interaction problems. A macro-scale interface direct shear apparatus having a test specimen footprint of 1.72 m × 1.75 m was designed and built for this purpose. The apparatus is capable of testing various soil-pipe interfaces under effective normal stresses in the range of 3 kPa to 6 kPa. A maximum shear displacement of 1.2 m is achievable at rates ranging from 0.1 μm/s to 1 mm/s. Sensors mounted at the interface enable the accurate determination of the effective normal stress at the interface when fully saturated fine-grained soils are tested. This paper presents some observations arising from a series of interface direct shear tests involving fine-grained soils of different plasticity against bare and epoxy coated steel surfaces.
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Rubinstein, Shmuel M., Gil Cohen, and Jay Fineberg. "Direct Observation of Frictional Contacts on a Sliding Interface." In ASME 2008 9th Biennial Conference on Engineering Systems Design and Analysis. ASMEDC, 2008. http://dx.doi.org/10.1115/esda2008-59211.
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Two blocks in frictional contact, are supported by a multitude of microscopic contacts whose real contact area, A, is much smaller than the nominal one. We measure the spatial and temporal behavior of A along a rough spatially extended interface. Using high speed imaging we record, both slow nucleation processes as well as rapid, crack like events that eventually lead to overall sliding of an entire frictional interface. We report that a discrete sequence of crack-like precursors propagating within the interface is excited by a slowly increasing shear force applied to the blocks, when the shear force is applied to a single edge of the sample. The precursors are triggered at shear stresses well bellow those usually associated with the static friction coefficient. They increase systematically in length and significantly redistribute the real area of contact. Thus when the critical shear force for sliding is reached, the initially uniform contact area along the interface has already evolved to one that is highly non-uniform in space. These results suggest a fundamentally new view of the processes leading to frictional motion with ramifications to earthquake dynamics and material failure.
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Kwon, Soonwook, Yuri Lee, and Bongtae Han. "Advanced Micro Shear Testing for Solder Alloy Using Direct Local Measurement." In ASME 2003 International Electronic Packaging Technical Conference and Exhibition. ASMEDC, 2003. http://dx.doi.org/10.1115/ipack2003-35325.
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A modified single lap shear test configuration, based on the Iosipescu geometry, is proposed for determination of the constitutive properties of solder alloys. An auxiliary device (extension unit) is introduced to improve the accuracy of measurement. The extension unit is attached directly to the specimen and it converts shear displacements to axial displacements, which are subsequently captured by a high-resolution extensometer. With aid of the extension unit, shear deformations are measured without compensating machine and grip compliance. The specimen configuration includes geometrical constraints at the solder/substrate interfaces in most electronic assemblies. Consequently, the results represent pseudo-continuum properties that take account for grain constraints at the solder/pad interface. They are properties that are more realistic for continuum mechanics based stress studies such as an FEM analysis.
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Xiao, Suguang, Muhannad T. Suleiman, Rehab Elzeiny, Huan Xie, and Mohammed Al-Khawaja. "Soil-Concrete Interface Properties Subjected to Temperature Changes and Cycles Using Direct Shear Tests." In Geotechnical Frontiers 2017. Reston, VA: American Society of Civil Engineers, 2017. http://dx.doi.org/10.1061/9780784480472.018.
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Houhou, Roba, Rayan Bou Mjahed, Salah Sadek, and Shadi Najjar. "Drained Interface Strength between Pipelines and Clays Using Tilt Table and Direct Shear Tests." In Geo-Congress 2020. Reston, VA: American Society of Civil Engineers, 2020. http://dx.doi.org/10.1061/9780784482827.002.
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Westgate, Zack, Ricardo Argiolas, Regis Wallerand, and Jean-Christophe Ballard. "Experience with Interface Shear Box Testing for Pipe-Soil Interaction Assessment on Sand." In Offshore Technology Conference. OTC, 2021. http://dx.doi.org/10.4043/31268-ms.
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Abstract This paper is a companion paper to OTC 28671, titled "Experience with Interface Shear Box Testing for Axial Pipe-Soil Interaction Assessment on Soft Clay", and presents a similar range of experience and best practice recommendations for geotechnical laboratory testing to determine soil properties relevant to pipeline-seabed friction on sandy seabeds. The paper is underpinned by a new database that demonstrates the driving parameters that influence interface friction in granular materials. By accurately quantifying shear resistance along the pipe-soil interface under low normal stresses imposed by subsea pipelines, design ranges in friction can be narrowed and/or tailored to specific pipeline conditions. These improved geotechnical inputs to pipe-soil interaction can alleviate unnecessary axial expansion mitigation and lateral stabilization measures, unlocking cost savings otherwise unavailable through conventional testing. A large database is presented, compiled from both previously published research and unpublished recent industry experience with low normal stress interface shear testing using various modified direct shear box devices. The test database comprises several coarse-grained soil types of both silica and carbonate minerology tested against pipeline coatings of various material, hardness and roughness. The database populates a framework for assessing frictional pipe-soil interaction response, illuminating key trends from normal stress, interface roughness and hardness, and particle angularity, which otherwise remain elusive when examined through individual test datasets. This database and the populated framework provides guidance to pipeline and geotechnical engineers in the form of a basis for initial estimates of axial and lateral friction of pipelines on sand and an approach for improving these estimates via focused site-specific testing. The test database includes previously unreleased project data collected over the past few years for offshore oil and gas projects. Similar to its predecessor paper on soft clays (OTC 28671), this paper shares the authors’ collective experience providing guidance on the planning, execution and interpretation of low stress interface shear tests in sands. The combined databases across both papers provide a significant improvement in early stage guidance for characterization of geotechnical soil properties for subsea pipeline design.
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Baykal, Go¨khan, and Ays¸e Edinc¸liler. "Clay-Concrete Pile Interface in Various Marine Environments." In ASME 2009 28th International Conference on Ocean, Offshore and Arctic Engineering. ASMEDC, 2009. http://dx.doi.org/10.1115/omae2009-80033.
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The interface shear strength between soil and concrete is an important design parameter for the calculation of the capacity of a pile. Due to small displacements required for the mobilization of the friction capacity of piles, the interface shear strength is a reliable parameter for the determination of axial pile capacity. For bored piles the end bearing capacity development requires large displacements for full mobilization. In the coastal regions piles are frequently used as deep foundation systems for several near shore and marine structures. The effect of different salt contents of various marine environments on the interface shear strength of pile soil interface is investigated. The objective of this study is to evaluate the interface properties between kaolinite clay sedimented at different salt contents and concrete to model the piles constructed in various marine environments ranging from Black Sea with the lowest salt content to Red Sea with the highest salt content. Kaolinite clay is mixed with marine salt and water at salt percentages of 0, 0.1, 0.2, 0.3, and 0.4 per cent by weight and the samples are placed in a consolidation cell. The mixtures are prepared at a water content of two times the liquid limit of kaolinite. The samples are consolidated at over consolidation ratios of 1, 2 and 4 to study the effect of stress history. Split samples are prepared having one half concrete and the other half clay. The direct shear test results revealed that the interface friction angle increased by increasing salt contents upto 20 per cent when compared to that of fresh water sedimented samples. The overconsolidation ratio did not cause a significant change in the interface properties for the case studied. The results of this preliminary study may help to understand better any change in salt content on the capacity of piles constructed at saline environments. Fresh water leaching of sediments formed at saline environments may be a concern when the capacity of piles is considered under such conditions.
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Bohach, Garrett, Md Minal Nahin, Eric Severson, and James D. Van de Ven. "Impact of Dynamics on the Losses at Radial Ball Piston Pump Interfaces." In BATH/ASME 2020 Symposium on Fluid Power and Motion Control. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/fpmc2020-2769.
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Abstract This paper presents a mathematical model of a radial ball piston pump/motor. The specific application of the pump is for direct integration with a high speed electric motor for use in off highway vehicles. The pump/motor must operate across all four quadrants with high flow rates at a low pressure differential. The model captures the major mechanical and volumetric losses within the hydraulic machine with specific attention given to the ball-cylinder interface and the pintle-rotor interface. The leakage and shear at the ball piston interface are dependent on the position of the ball piston in the cylinder; therefore, the dynamics of the ball piston are calculated. The pintle-rotor model includes the port geometry, which influences the flow rates into and out of the pump/motor. Leakage and shear at the interface are dependent on the gap height between the two surfaces; consequently, the model calculates the radial forces acting on the rotor and uses journal bearing theory to predict the eccentricity. This eccentricity balances the other forces and is necessary to determine the interface losses. Lastly, the importance of these dynamics is evaluated to determine which are needed in a future optimization framework. It is shown that considering the dynamics of both interfaces captures significantly more losses and results in a more accurate model than an earlier simplified one.
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Cezo, James D., Virginia L. Ferguson, Kenneth D. Taylor, and Mark E. Rentschler. "Measurement of Bond Strength of Direct Heat Tissue Fusion in Arteries." In ASME 2012 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/sbc2012-80138.
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Tissue fusion is a method of joining tissue using heat and pressure. Several surgical tool companies have developed devices which perform tissue fusion on blood vessels in order to perform ligation of the vessel [1]. The success or failure of these devices is contingent upon the strength of the bond it creates between opposing sides of the blood vessel lumen, yet little characterization has been done to measure the strength of this interface. Previous studies have examined the strength of tissue fusion using clinically relevant metrics such as burst pressure or tearing strength, but none have explored metrics more appropriate for determining the mechanics of the actual bond, such as peel strength or shear strength [2–3]. These clinical metrics are susceptible to large variations due to tissue composition and geometry. The goal of this study is to measure the bond’s modulus and strength using standard engineering methods. The motivation of the present work is to develop a method for quantitatively measuring the strength of the bond made during tissue fusion. This method can then be applied to quantify the strength of the fusion interface between arterial tissue using other devices and aid in future evaluation and development of tissue fusion devices to maximize the bond strength.
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Ahmadi, Eisa, and M. M. Aghdam. "A Truly Generalized Plane Strain Meshless Model for Combined Normal and Shear Loading of Fiber Reinforced Materials." In ASME 2010 International Mechanical Engineering Congress and Exposition. ASMEDC, 2010. http://dx.doi.org/10.1115/imece2010-40580.
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A truly meshless method based on the integral form of equilibrium equations is formulated. A micromechanical model is developed to study micro-stresses in normal and shear loading of unidirectional fiber reinforced composites. A small repeating area of composite including a fiber surrounded by matrix called representative volume element (RVE) is considered as solution domain. A direct method is proposed for enforcement of the appropriate periodic boundary conditions for shear and normal loading. Especially transverse shear loading is considered in this analysis. Fully bonded interface condition is investigated and the continuity of displacements and traction is imposed to the fiber-matrix interface. Comparison of the predicted results shows excellent agreement with results in available literature. Results of this study also revealed that the presented model can provide highly accurate predictions with respectively small number of nodes and small computation time without the complexity of mesh generation.
Reports on the topic "Interface direct shear"
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Rahman, Shahedur, Rodrigo Salgado, Monica Prezzi, and Peter J. Becker. Improvement of Stiffness and Strength of Backfill Soils Through Optimization of Compaction Procedures and Specifications. Purdue University, 2020. http://dx.doi.org/10.5703/1288284317134.
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Vibration compaction is the most effective way of compacting coarse-grained materials. The effects of vibration frequency and amplitude on the compaction density of different backfill materials commonly used by INDOT (No. 4 natural sand, No. 24 stone sand, and No. 5, No. 8, No. 43 aggregates) were studied in this research. The test materials were characterized based on the particle sizes and morphology parameters using digital image analysis technique. Small-scale laboratory compaction tests were carried out with variable frequency and amplitude of vibrations using vibratory hammer and vibratory table. The results show an increase in density with the increase in amplitude and frequency of vibration. However, the increase in density with the increase in amplitude of vibration is more pronounced for the coarse aggregates than for the sands. A comparison of the maximum dry densities of different test materials shows that the dry densities obtained after compaction using the vibratory hammer are greater than those obtained after compaction using the vibratory table when both tools were used at the highest amplitude and frequency of vibration available. Large-scale vibratory roller compaction tests were performed in the field for No. 30 backfill soil to observe the effect of vibration frequency and number of passes on the compaction density. Accelerometer sensors were attached to the roller drum (Caterpillar, model CS56B) to measure the frequency of vibration for the two different vibration settings available to the roller. For this roller and soil tested, the results show that the higher vibration setting is more effective. Direct shear tests and direct interface shear tests were performed to study the impact of particle characteristics of the coarse-grained backfill materials on interface shear resistance. The more angular the particles, the greater the shear resistance measured in the direct shear tests. A unique relationship was found between the normalized surface roughness and the ratio of critical-state interface friction angle between sand-gravel mixture with steel to the internal critical-state friction angle of the sand-gravel mixture.
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Sobolik, Steven R., and Benjamin Reedlunn. Shear Behavior of Bedded Salt Interfaces under Direct Shear Loading. Office of Scientific and Technical Information (OSTI), October 2019. http://dx.doi.org/10.2172/1569654.
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