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Littérature scientifique sur le sujet « Mechanical constitutive law »

Auteur : Grafiati

Publié le 12 avril 2025

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Articles de revues sur le sujet "Mechanical constitutive law"

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May-Newman, K., et F. C. P. Yin. « A Constitutive Law for Mitral Valve Tissue ». Journal of Biomechanical Engineering 120, n^o 1 (1 février 1998) : 38–47. http://dx.doi.org/10.1115/1.2834305.

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Biaxial mechanical testing and theoretical continuum mechanics analysis are employed to formulate a constitutive law for cardiac mitral valve anterior and posterior leaflets. A strain energy description is formulated based on the fibrous architecture of the tissue, accurately describing the large deformation, highly nonlinear transversely isotropic material behavior. The results show that a simple three-coefficient exponential constitutive law provides an accurate prediction of stress–stretch behavior over a wide range of deformations. Regional heterogeneity may be accommodated by spatially varying a single coefficient and incorporating collagen fiber angle. The application of this quantitative information to mechanical models and bioprosthetic development could provide substantial improvement in the evaluation and treatment of valvular disease, surgery, and replacement.

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Mahajan, Puneet, et Robert L. Brown. « A microstructure-based constitutive law for snow ». Annals of Glaciology 18 (1993) : 287–94. http://dx.doi.org/10.3189/s0260305500011666.

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A constitutive theory of snow is developed to describe the mechanical properties of snow in terms of the properties of the ice grains and the necks that interconnect them. The principle of virtual work is used to calculate the stresses in the particles and necks. A number of different deformation mechanisms are investigated and, depending upon the deformation mechanism which is dominant for given load conditions, different equations are used to calculate the strains in the grains and necks. These strains around a representative ice grain are then averaged and scaled to obtain the global strains in the snow. The theory is then compared with experimental data to determine if the mechanical properties of snow can be adequately represented. Results show that the constitutive theory does work, but that it is cumbersome to implement, and that for practical use substantial computational capability is needed.

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Mahajan, Puneet, et Robert L. Brown. « A microstructure-based constitutive law for snow ». Annals of Glaciology 18 (1993) : 287–94. http://dx.doi.org/10.1017/s0260305500011666.

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A constitutive theory of snow is developed to describe the mechanical properties of snow in terms of the properties of the ice grains and the necks that interconnect them. The principle of virtual work is used to calculate the stresses in the particles and necks. A number of different deformation mechanisms are investigated and, depending upon the deformation mechanism which is dominant for given load conditions, different equations are used to calculate the strains in the grains and necks. These strains around a representative ice grain are then averaged and scaled to obtain the global strains in the snow. The theory is then compared with experimental data to determine if the mechanical properties of snow can be adequately represented. Results show that the constitutive theory does work, but that it is cumbersome to implement, and that for practical use substantial computational capability is needed.

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Bacca, Mattia, et Robert M. McMeeking. « A viscoelastic constitutive law for hydrogels ». Meccanica 52, n^o 14 (8 février 2017) : 3345–55. http://dx.doi.org/10.1007/s11012-017-0636-y.

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Liu, Qing Feng, Ning Chang Wang, Lan Yan, Feng Jiang et Hui Huang. « The Dynamic Mechanical Properties of Oxygen Free Copper under the Impact Load ». Advanced Materials Research 1136 (janvier 2016) : 543–48. http://dx.doi.org/10.4028/www.scientific.net/amr.1136.543.

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The dynamic mechanical properties of oxygen free copper has been tested under the different strain rate (4700s-1~21000s-1) at the room temperature by split Hopkinson pressure bar (SHPB), the true stress-true strain curves has been obtained. Power-Law constitutive model and Johnson-Cook constitutive model have been built to fit the experimental result from SHPB test of oxygen free copper, meanwhile, the constitutive model can be applied to the simulation analysis of cutting process. The results show that the oxygen free copper is sensitive to the strain rate. In addition, the Johnson-Cook constitutive model predicts the plastic flow stress of the oxygen free copper more accurately than the Power-Law constitutive model at the high strain rate.

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Horowitz, A., Y. Lanir, F. C. P. Yin, M. Perl, I. Sheinman et R. K. Strumpf. « Structural Three-Dimensional Constitutive Law for the Passive Myocardium ». Journal of Biomechanical Engineering 110, n^o 3 (1 août 1988) : 200–207. http://dx.doi.org/10.1115/1.3108431.

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A three-dimensional constitutive law is proposed for the myocardium. Its formulation is based on a structural approach in which the total strain energy of the tissue is the sum of the strain energies of its constituents: the muscle fibers, the collagen fibers and the fluid matrix which embeds them. The ensuing material law expresses the specific structural and mechanical properties of the tissue, namely, the spatial orientation of the comprising fibers, their waviness in the unstressed state and their stress-strain behavior when stretched. Having assumed specific functional forms for the distribution of the fibers spatial orientation and waviness, the results of biaxial mechanical tests serve for the estimation of the material constants appearing in the constitutive equations. A very good fit is obtained between the measured and the calculated stresses, indicating the suitability of the proposed model for describing the mechanical behavior of the passive myocardium. Moreover, the results provide general conclusions concerning the structural basis for the tissue overall mechanical properties, the main of which is that the collagen matrix, though comprising a relatively small fraction of the whole tissue volume, is the dominant component accounting for its stiffness.

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Bischoff, J. E., E. A. Arruda et K. Grosh. « A Microstructurally Based Orthotropic Hyperelastic Constitutive Law ». Journal of Applied Mechanics 69, n^o 5 (16 août 2002) : 570–79. http://dx.doi.org/10.1115/1.1485754.

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A constitutive model is developed to characterize a general class of polymer and polymer-like materials that displays hyperelastic orthotropic mechanical behavior. The strain energy function is derived from the entropy change associated with the deformation of constituent macromolecules and the strain energy change associated with the deformation of a representative orthotropic unit cell. The ability of this model to predict nonlinear, orthotropic elastic behavior is examined by comparing the theory to experimental results in the literature. Simulations of more complicated boundary value problems are performed using the finite element method.

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Naderi, A., et AR Saidi. « Common nonlocal elastic constitutive relation and material-behavior modeling of nanostructures ». Proceedings of the Institution of Mechanical Engineers, Part N : Journal of Nanomaterials, Nanoengineering and Nanosystems 231, n^o 2 (juin 2017) : 83–87. http://dx.doi.org/10.1177/2397791417712870.

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This article reviews conventional nonlocal elasticity constitutive relation which is frequently used for mechanical analyses of nanostructures. It is shown here that since this constitutive relation has been essentially derived based on infinite-body assumption, it cannot consider the nonlocal effects at all points of a nanoscale body accurately. Also, it is shown that although the nonlocal constitutive relations can potentially consider the surface effects, that constitutive relation has been obtained substantially by ignoring those effects. So, it cannot also consider the surface effects accurately. Therefore, the conventional nonlocal constitutive relation generally is not accurate for material-behavior modeling and consequently mechanical analysis of nanostructures. Furthermore, common nonlocal constitutive law is examined in buckling problem of Timoshenko beam-columns to show another limitation of that constitutive law. Finally, some special cases for which that constitutive relation can be used more accurately are proposed.

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Lin, D. H. S., et F. C. P. Yin. « A Multiaxial Constitutive Law for Mammalian Left Ventricular Myocardium in Steady-State Barium Contracture or Tetanus ». Journal of Biomechanical Engineering 120, n^o 4 (1 août 1998) : 504–17. http://dx.doi.org/10.1115/1.2798021.

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The constitutive law of the material comprising any structure is essential for mechanical analysis since this law enables calculation of the stresses from the deformations and vice versa. To date, there is no constitutive law for actively contracting myocardial tissue. Using 2,3-butanedione monoxime to protect the myocardium from mechanical trauma, we subjected thin midwall slices of rabbit myocardium to multiaxial stretching first in the passive state and then during steady-state barium contracture or during tetani in ryanodine-loaded tissue. Assuming transverse isotropy in both the passive and active conditions, we used our previously described methods (Humphrey et al., 1990a) to obtain both passive and active constitutive laws. The major results of this study are: (1) This is the first multiaxial constitutive law for actively contracting mammalian myocardium. (2) The functional forms of the constitutive law for barium contracture and ryanodine-induced tetani are the same but differ from those in the passive state. Hence, one cannot simply substitute differing values for the coefficients of the passive law to describe the active tissue properties. (3) There are significant stresses developed in the cross-fiber direction (more than 40 percent of those in the fiber direction) that cannot be attributed to either deformation effects or nonparallel muscle fibers. These results provide the foundation for future mechanical analyses of the heart.

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Francillette, H., A. Gavrus et R. A. Lebensohn. « A constitutive law for the mechanical behavior of Zr 702α ». Journal of Materials Processing Technology 142, n^o 1 (novembre 2003) : 43–51. http://dx.doi.org/10.1016/s0924-0136(03)00439-4.

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Thèses sur le sujet "Mechanical constitutive law"

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Wang, Shun-Sheng. « Development of constitutive model for Al-2011 alloy in mushy state ». Ohio University / OhioLINK, 1994. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1174224280.

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Stang, Eric Thomas. « Constitutive Modeling of Creep in Leaded and Lead-Free Solder Alloys Using Constant Strain Rate Tensile Testing ». Wright State University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=wright1548338008633472.

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Kuykendall, Katherine Lynn. « An Evaluation of Constitutive Laws and their Ability to Predict Flow Stress over Large Variations in Temperature, Strain, and Strain Rate Characteristic of Friction Stir Welding ». BYU ScholarsArchive, 2011. https://scholarsarchive.byu.edu/etd/2768.

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Constitutive laws commonly used to model friction stir welding have been evaluated, both qualitatively and quantitatively, and a new application of a constitutive law which can be extended to materials commonly used in FSW is presented. Existing constitutive laws have been classified as path-dependent or path-independent. Path-independent laws have been further classified according to the physical phenomena they capture: strain hardening, strain rate hardening, and/or thermal softening. Path-dependent laws can track gradients in temperature and strain rate characteristic to friction stir welding; however, path-independent laws cannot. None of the path-independent constitutive laws evaluated has been validated over the full range of strain, strain rate, and temperature in friction stir welding. Holding all parameters other than constitutive law constant in a friction stir weld model resulted in temperature differences of up to 21%. Varying locations for maximum temperature difference indicate that the constitutive laws resulted in different temperature profiles. The Sheppard and Wright law is capable of capturing saturation but incapable of capturing strain hardening with errors as large as 57% near yield. The Johnson-Cook law is capable of capturing strain hardening; however, its inability to capture saturation causes over-predictions of stress at large strains with errors as large as 37% near saturation. The Kocks and Mecking model is capable of capturing strain hardening and saturation with errors less than 5% over the entire range of plastic strain. The Sheppard and Wright and Johnson-Cook laws are incapable of capturing transients characteristic of material behavior under interrupted temperature or strain rate. The use of a state variable in the Kocks and Mecking law allows it to predict such transients. Constants for the Kocks and Mecking model for AA 5083, AA 3004, and Inconel 600 were determined from Atlas of Formability data. Constants for AA 5083 and AA 3004 were determined with the traditional Kocks and Mecking model; however, constants for Inconel 600 could not be determined without modification to the model. The temperature and strain rate combinations for Inconel 600 fell into two hardening domains: low temperatures and high strain rates exhibited twinning while high temperatures and low strain rates exhibited slip. An additional master curve was added to the Kocks and Mecking model to account for two hardening mechanisms. The errors for the Kocks and Mecking model predictions are generally within 10% for all materials analyzed.

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Hrubanová, Anna. « Vliv mechanických vlastností tkání na napětí v patologické krční tepně ». Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2021. http://www.nusl.cz/ntk/nusl-443719.

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This thesis deals with determination of representative constitutive model for describing atherosclerotic carotid artery behavior. The first part of the thesis provides brief summary of medical knowledge needed as well as detailed describtion of current experimental methods for determination of mechanical properties of atherosclerotic arteries. The main part is focused on mechanical testing of atheroslecotic carotid arteries. The description of sample preparation, testing device and the experiment itself is involved. Statistical analysis of measured data is done, focusing on comparison of factors potentially influencing mechanical behavior. In conclusion, the FEA analysis on simplified geometry of carotid artery with atheroma is performed. Emphasis is placed on the impact of material model obtained from experiments on equivalent stress in fibrous cap.

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Wu, Xijia. « Constitutive laws of plastic deformation and fracture ». Thesis, University of Ottawa (Canada), 1992. http://hdl.handle.net/10393/7821.

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Environment assisted fatigue involves plastic deformation and degrading chemical reactions, which occur in a localized region ahead of the crack tip. Basically, transgranular crack growth proceeds by alternating slip processes. In this study, a transgranular fatigue crack growth rate model is developed on the basis of restricted slip reversibility (RSR), where transgranular fatigue crack growth rate is related to plastic deformation accommodation ahead of the crack tip (the product of the cyclic plastic strain range and the plastic zone size). The model is shown to take the form of the Paris equation with a power law exponent of 3 at positive R values. Fatigue crack growth behavior of a 8090 aluminum-lithium alloy has been examined by a series of tests using compact tension (C(T)) specimens with the load axis (a) parallel to the rolling direction (LT specimen), (b) inclined at 15$\sp\circ$ (L + 15$\sp\circ$), (c) inclined at 30$\sp\circ$ (L + 30$\sp\circ$), (d) inclined at 45$\sp\circ$ (L + 45$\sp\circ$) to the rolling direction. It has been found that in the LT, L + 15$\sp\circ$ and L + 30$\sp\circ$ specimens macroscopic cracks propagate along the plane normal to the rolling direction regardless of the deviation of loading directions and the fatigue crack in the L + 45$\sp\circ$ specimen propagates along the plane of specimen symmetry. Fatigue crack growth rate has been found to vary with the specimen orientation with the LT direction exhibiting the best fatigue crack growth resistance. These phenomena are discussed in terms of the crystallographic texture and the highly planar slip behavior of this ally. A revised RSR model is developed for the description of transgranular fatigue crack growth in aluminum-lithium alloys, where the effect of texture is related to a geometric factor for the favorable slip planes. Extension of the RSR model to environment assisted fatigue is also discussed. It is recognized that environmental effects contribute to crack propagation by the formation and rupture of an embrittlement zone in front of the crack tip. By incorporating a corrosion damage zone into the RSR model, fatigue crack growth rate in a deleterious environment is shown to be consists of two components: (i) mechanical fatigue which occurs by partially reversible slip and (ii) environmental enhancement of crack growth that results from the rupture of the embrittlement zone and is directly related to the characteristic dimension of this corrosion damage zone. In addition, fracture kinetics analysis is extended to crack growth behavior which exhibits the positive-negative temperature dependence. A constitutive law is derived from the general rate equation for a two-barrier consecutive system which represents stress corrosion cracking. The transition condition of the positive-negative temperature dependence is discussed and defined in terms of microstructural characteristic quantities (activation energy and work factor) and loading constraints (stress intensity factor and temperature). For the description of plastic deformation, a set of evolutionary rate equations is developed from deformation kinetics theory. Corresponding constitutive equations are derived for the dislocation glide mechanism, glide-plus-climb mechanism and diffusional flow. The operational equations are solved from the governing differential rate equation to determine deformation responses under different loading constraints.

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Miller, Matthew P. « Improved constitutive laws for finite strain inelastic deformation ». Diss., Georgia Institute of Technology, 1993. http://hdl.handle.net/1853/16098.

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De, Vittorio Giancarlo. « Crack measurements in structural concrete with D.I.C. system and validation of a tensile constitutive law ». Master's thesis, Alma Mater Studiorum - Università di Bologna, 2011. http://amslaurea.unibo.it/2048/.

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Compared with other mature engineering disciplines, fracture mechanics of concrete is still a developing field and very important for structures like bridges subject to dynamic loading. An historical point of view of what done in the field is provided and then the project is presented. The project presents an application of the Digital Image Correlation (DIC) technique for the detection of cracks at the surface of concrete prisms (500mmx100mmx100mm) subject to flexural loading conditions (Four Point Bending test). The technique provide displacement measurements of the region of interest and from this displacement field information about crack mouth opening (CMOD) are obtained and related to the applied load. The evolution of the fracture process is shown through graphs and graphical maps of the displacement at some step of the loading process. The study shows that it is possible with the DIC system to detect the appearance and evolution of cracks, even before the cracks become visually detectable.

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Günther, Ralf-Michael. « Erweiterter Dehnungs-Verfestigungs-Ansatz ». Doctoral thesis, Technische Universitaet Bergakademie Freiberg Universitaetsbibliothek "Georgius Agricola", 2010. http://nbn-resolving.de/urn:nbn:de:bsz:105-qucosa-27196.

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Gegenstand der Dissertation ist die Entwicklung eines Stoffmodells für duktile Salzgesteine, mit dem alle drei Kriechphasen, abhängig von einem inneren Zustandsparameter, beschrieben werden können. Die Modellierung der Schädigungs- bzw. Dilatanzentwicklung und deren Rückkopplung auf das Kriechverhalten ist das Kernstück der Stoffmodellentwicklung. Es wird eine Beziehung abgeleitet, die die Dilatanzentwicklung abhängig vom Manteldruck und der spezifischen Formänderungsarbeit beschreibt. Durch diese Formulierung und deren Verknüpfung mit dem o. g. Zustandsparameter lassen sich tertiäres Kriechen, Kriechbruch, Nachbruchverhalten und Restfestigkeit geschwindigkeitsabhängig beschreiben. Es erfolgte eine Validierung des Modells anhand von Laboruntersuchungen. Weiter wurden Parametersätze für zwei unterschiedliche Steinsalztypen abgeleitet. Anhand von drei realen Problemstellungen konnte gezeigt werden, dass das gemessene In-situ-Verhalten mit dem Modell berechnet werden kann und Prognoseberechnungen zu plausiblen Ergebnissen führen.

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Günther, Ralf-Michael. « Erweiterter Dehnungs-Verfestigungs-Ansatz : Phänomenologisches Stoffmodell für duktile Salzgesteine zur Beschreibung primären, sekundären und tertiären Kriechens ». Doctoral thesis, TU Bergakademie Freiberg, 2009. https://tubaf.qucosa.de/id/qucosa%3A22710.

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Gegenstand der Dissertation ist die Entwicklung eines Stoffmodells für duktile Salzgesteine, mit dem alle drei Kriechphasen, abhängig von einem inneren Zustandsparameter, beschrieben werden können. Die Modellierung der Schädigungs- bzw. Dilatanzentwicklung und deren Rückkopplung auf das Kriechverhalten ist das Kernstück der Stoffmodellentwicklung. Es wird eine Beziehung abgeleitet, die die Dilatanzentwicklung abhängig vom Manteldruck und der spezifischen Formänderungsarbeit beschreibt. Durch diese Formulierung und deren Verknüpfung mit dem o. g. Zustandsparameter lassen sich tertiäres Kriechen, Kriechbruch, Nachbruchverhalten und Restfestigkeit geschwindigkeitsabhängig beschreiben. Es erfolgte eine Validierung des Modells anhand von Laboruntersuchungen. Weiter wurden Parametersätze für zwei unterschiedliche Steinsalztypen abgeleitet. Anhand von drei realen Problemstellungen konnte gezeigt werden, dass das gemessene In-situ-Verhalten mit dem Modell berechnet werden kann und Prognoseberechnungen zu plausiblen Ergebnissen führen.

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Jelvehpour, Ali. « Development of a transient gradient enhanced non local continuum damage mechanics model for masonry ». Thesis, Queensland University of Technology, 2016. https://eprints.qut.edu.au/93365/1/Ali_Jelvehpour_Thesis.pdf.

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Due to the advent of varied types of masonry systems a comprehensive failure mechanism of masonry essential for the understanding of its behaviour is impossible to be determined from experimental testing. As masonry is predominantly used in wall structures a biaxial stress state dominates its failure mechanism. Biaxial testing will therefore be necessary for each type of masonry, which is expensive and time consuming. A computational method would be advantageous; however masonry is complex to model which requires advanced computational modelling methods. This thesis has formulated a damage mechanics inspired modelling method and has shown that the method effectively determines the failure mechanisms and deformation characteristics of masonry under biaxial states of loading.

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Livres sur le sujet "Mechanical constitutive law"

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Whyatt, J. K. Numerical exploration of shear-fracture-related rock bursts using a strain-softening constitutive law. Washington : U.S. Dept. of the Interior, Bureau of Mines, 1991.

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Carlo, Pedretti, Melani Margherita et Basilique nationale du Sacré-Coeur (Belgium), dir. Leonardo da Vinci : The European genius : paintings and drawings : exhibition in the Basilica of Koekelberg, Brussels, in celebration of the 50th anniversary of the Treaty of Rome for the constitution of the European Community (1957-2007). Foligno (PG) [i.e. Perugia, Italy] : Cartei & Bianchi, 2007.

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Schupmann, Benjamin A. The Absolute Constitution. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198791614.003.0005.

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Chapter 4 analyzes Schmitt’s constitutional theory and how it complements his state theory. It begins with Schmitt’s criticism of the predominant positivist conception of the constitution. Schmitt argued that the positivists’ “relativized” conception of the constitution was committed above all to the equal chance of any belief to be enacted into law. This chapter then analyzes Schmitt’s counterargument that, without a prior and “absolute” commitment to some substantive value, a constitution could not fulfill its basic purpose of providing a clearly defined and stable public order. Schmitt’s typology of Relative and Absolute Constitution maps onto his state theoretical distinction between mechanical state and absolute state. This chapter concludes by discussing Schmitt’s later analysis of the concept nomos and how his analysis builds on and develops his earlier work on the concept of the absolute constitution.

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James A, Green. Part I The Origin and Legal Source of the Persistent Objector Rule, 2 The Persistent Objector Rule in Case Law and State Practice Post-1945. Oxford University Press, 2016. http://dx.doi.org/10.1093/law/9780198704218.003.0003.

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This chapter continues to assess the legal status of the persistent objector rule by examining its basis in post-1945 case law and post-1945 state practice and opinio juris. The support for the existence of the persistent objector rule in the academic world, while being relavant to, and perhaps indicative of, the emergence of the rule, cannot be viewed as enough to constitute the rule as a matter of international law in itself. Investigation in this chapter reveals a relatively small but cumulatively convincing degree of support for the persistent objector rule. Further investigation into this body of practice will allow for the analyse of the mechanics of the rule: it is one thing to conclude that it exists, but how does it function?

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Glennan, Stuart. Mechanisms. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780198779711.003.0002.

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This chapter introduces the account of minimal mechanism, according to which a mechanism consists of a set of parts or entities whose activities and interactions are organized so as to be responsible for some phenomenon. The concepts appealed to in this account—phenomena, entities, activities, organization—are elaborated, and the relation of minimal mechanism to other accounts is explored. Mechanisms are shown to be compounds that are organized in two dimensions, the horizontal dimension of causal dependence and a vertical or part-whole dimension called mechanistic constitution. I argue that almost all natural and social phenomena depend upon mechanisms so characterized, and that this fact leads to a new mechanical ontology, which alters the way we should think about traditional metaphysical categories like substances, processes, properties, dispositions, causes, and laws of nature.

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Kerr, Orin. The Digital Fourth Amendment. Oxford University PressNew York, NY, 2024. http://dx.doi.org/10.1093/9780190627102.001.0001.

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Abstract When can the government read your email or monitor your web surfing? When can the police search your phone or copy your computer files? In the United States, the answers come from the Fourth Amendment to the Constitution and its ban on “unreasonable searches and seizures.” The Digital Fourth Amendment: Privacy and Policing in Our Online World takes the reader inside the legal world of how courts are interpreting the Fourth Amendment in the digital age. Computers, smartphones, and the Internet have transformed criminal investigations, and even a routine crime is likely to lead to digital evidence. But courts are struggling to apply old Fourth Amendment concepts to the new digital world. Mechanically applying old rules from physical investigations doesn’t make sense, often leading to dramatic expansions of government power based only on coincidences of computer design. Written by a prominent law professor whose scholarship has often been relied on by courts in the field, The Digital Fourth Amendment shows how judges must craft new rules for the new world of digital evidence. It explains the challenges courts confront as they translate old protections to a new technological world, bringing the reader up to date on the latest cases and rulings. Informed by legal history and the latest technology, this book gives courts a blueprint for legal change with clear rules for courts to adopt to restore our constitutional rights in the computer age.

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Zydroń, Tymoteusz. Wpływ systemów korzeniowych wybranych gatunków drzew na przyrost wytrzymałości gruntu na ścinanie. Publishing House of the University of Agriculture in Krakow, 2019. http://dx.doi.org/10.15576/978-83-66602-46-5.

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The aim of the paper was to determine the influence of root systems of chosen tree species found in the Polish Flysch Carpathians on the increase of soil shear strength (root cohesion) in terms of slope stability. The paper's goal was achieved through comprehensive tests on root systems of eight relatively common in the Polish Flysch Carpathians tree species. The tests that were carried out included field work, laboratory work and analytical calculations. As part of the field work, the root area ratio (A IA) of the roots was determined using the method of profiling the walls of the trench at a distance of about 1.0 m from the tree trunk. The width of the. trenches was about 1.0 m, and their depth depended on the ground conditions and ranged from 0.6 to 1.0 m below the ground level. After preparing the walls of the trench, the profile was divided into vertical layers with a height of 0.1 m, within which root diameters were measured. Roots with diameters from 1 to 10 mm were taken into consideration in root area ratio calculations in accordance with the generally accepted methodology for this type of tests. These measurements were made in Biegnik (silver fir), Ropica Polska (silver birch, black locust) and Szymbark (silver birch, European beech, European hornbeam, silver fir, sycamore maple, Scots pine, European spruce) located near Gorlice (The Low Beskids) in areas with unplanned forest management. In case of each tested tree species the samples of roots were taken, transported to the laboratory and then saturated with water for at least one day. Before testing the samples were obtained from the water and stretched in a. tensile testing machine in order to determine their tensile strength and flexibility. In general, over 2200 root samples were tested. The results of tests on root area ratio of root systems and their tensile strength were used to determine the value of increase in shear strength of the soils, called root cohesion. To this purpose a classic Wu-Waldron calculation model was used as well as two types of bundle models, the so called static model (Fiber Bundle Model — FIRM, FBM2, FBM3) and the deformation model (Root Bundle Model— RBM1, RBM2, mRBM1) that differ in terms of the assumptions concerning the way the tensile force is distributed to the roots as well as the range of parameters taken into account during calculations. The stability analysis of 8 landslides in forest areas of Cicikowicleie and Wignickie Foothills was a form of verification of relevance of the obtained calculation results. The results of tests on root area ratio in the profile showed that, as expected, the number of roots in the soil profile and their ApIA values are very variable. It was shown that the values of the root area ratio of the tested tree species with a diameter 1-10 ram are a maximum of 0.8% close to the surface of the ground and they decrease along with the depth reaching the values at least one order of magnitude lower than close to the surface at the depth 0.5-1.0 m below the ground level. Average values of the root area ratio within the soil profile were from 0.05 to 0.13% adequately for Scots pine and European beech. The measured values of the root area ratio are relatively low in relation to the values of this parameter given in literature, which is probably connected with great cohesiveness of the soils and the fact that there were a lot of rock fragments in the soil, where the tests were carried out. Calculation results of the Gale-Grigal function indicate that a distribution of roots in the soil profile is similar for the tested species, apart from the silver fir from Bie§nik and European hornbeam. Considering the number of roots, their distribution in the soil profile and the root area ratio it appears that — considering slope stability — the root systems of European beech and black locust are the most optimal, which coincides with tests results given in literature. The results of tensile strength tests showed that the roots of the tested tree species have different tensile strength. The roots of European beech and European hornbeam had high tensile strength, whereas the roots of conifers and silver birch in deciduous trees — low. The analysis of test results also showed that the roots of the studied tree species are characterized by high variability of mechanical properties. The values Of shear strength increase are mainly related to the number and size (diameter) of the roots in the soil profile as well as their tensile strength and pullout resistance, although they can also result from the used calculation method (calculation model). The tests showed that the distribution of roots in the soil and their tensile strength are characterized by large variability, which allows the conclusion that using typical geotechnical calculations, which take into consideration the role of root systems is exposed to a high risk of overestimating their influence on the soil reinforcement. hence, while determining or assuming the increase in shear strength of soil reinforced with roots (root cohesion) for design calculations, a conservative (careful) approach that includes the most unfavourable values of this parameter should be used. Tests showed that the values of shear strength increase of the soil reinforced with roots calculated using Wu-Waldron model in extreme cases are three times higher than the values calculated using bundle models. In general, the most conservative calculation results of the shear strength increase were obtained using deformation bundle models: RBM2 (RBMw) or mRBM1. RBM2 model considers the variability of strength characteristics of soils described by Weibull survival function and in most cases gives the lowest values of the shear strength increase, which usually constitute 50% of the values of shear strength increase determined using classic Wu-Waldron model. Whereas the second model (mRBM1.) considers averaged values of roots strength parameters as well as the possibility that two main mechanism of destruction of a root bundle - rupture and pulling out - can occur at the same. time. The values of shear strength increase calculated using this model were the lowest in case of beech and hornbeam roots, which had high tensile strength. It indicates that in the surface part of the profile (down to 0.2 m below the ground level), primarily in case of deciduous trees, the main mechanism of failure of the root bundle will be pulling out. However, this model requires the knowledge of a much greater number of geometrical parameters of roots and geotechnical parameters of soil, and additionally it is very sensitive to input data. Therefore, it seems practical to use the RBM2 model to assess the influence of roots on the soil shear strength increase, and in order to obtain safe results of calculations in the surface part of the profile, the Weibull shape coefficient equal to 1.0 can be assumed. On the other hand, the Wu-Waldron model can be used for the initial assessment of the shear strength increase of soil reinforced with roots in the situation, where the deformation properties of the root system and its interaction with the soil are not considered, although the values of the shear strength increase calculated using this model should be corrected and reduced by half. Test results indicate that in terms of slope stability the root systems of beech and hornbeam have the most favourable properties - their maximum effect of soil reinforcement in the profile to the depth of 0.5 m does not usually exceed 30 kPa, and to the depth of 1 m - 20 kPa. The root systems of conifers have the least impact on the slope reinforcement, usually increasing the soil shear strength by less than 5 kPa. These values coincide to a large extent with the range of shear strength increase obtained from the direct shear test as well as results of stability analysis given in literature and carried out as part of this work. The analysis of the literature indicates that the methods of measuring tree's root systems as well as their interpretation are very different, which often limits the possibilities of comparing test results. This indicates the need to systematize this type of tests and for this purpose a root distribution model (RDM) can be used, which can be integrated with any deformation bundle model (RBM). A combination of these two calculation models allows the range of soil reinforcement around trees to be determined and this information might be used in practice, while planning bioengineering procedures in areas exposed to surface mass movements. The functionality of this solution can be increased by considering the dynamics of plant develop¬ment in the calculations. This, however, requires conducting this type of research in order to obtain more data.

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Chapitres de livres sur le sujet "Mechanical constitutive law"

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Tsai, C. T., V. K. Mathews, T. S. Gross, O. W. Dillon et R. J. De Angelis. « Constitutive Law for Calculating Plastic Deformations During CZ Silicon Crystal Growth ». Dans Mechanical Behavior of Materials, 349–55. Dordrecht : Springer Netherlands, 1990. http://dx.doi.org/10.1007/978-94-009-1968-6_40.

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Duchêne, Laurent, Hélène Morch, Carlos Rojas-Ulloa, Víctor Tuninetti et Anne Marie Habraken. « Efficient Thermo-Mechanical Modelling of Cyclic Loading with Chaboche Type Constitutive Law Coupled with Damage ». Dans Lecture Notes in Mechanical Engineering, 284–94. Cham : Springer Nature Switzerland, 2023. http://dx.doi.org/10.1007/978-3-031-42093-1_28.

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Chen, Yunkai, Peng Deng et Yao Wang. « Experimental and Analyses on the Deterioration of Mechanical Properties of Transport Bridges Based on Hot and Humid Marine Environment ». Dans Lecture Notes in Civil Engineering, 25–38. Singapore : Springer Nature Singapore, 2024. https://doi.org/10.1007/978-981-97-6238-5_3.

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AbstractThe mechanical properties of in-service concrete bridges in the sea are subject to accelerated deterioration due to the harsh environment in which they are located, which poses a serious challenge to bridge transportation work. Therefore, it is necessary to analyse and study the mechanical property evolution of lightweight aggregate concrete in the marine environment and transport engineering design. In order to study the mechanical property degradation law of nano-modified ceramic concrete under the action of dry and wet cycles and temperature, tests were conducted on nano-modified ceramic concrete specimens at different temperatures (30 °C, 40 °C, 50 °C) and different numbers of dry and wet cycles (15, 45, 75), respectively. The test results showed that with the increase of the number of cycles, the change of compressive strength showed a typical three-phase law, while the split tensile strength showed the law of deterioration, strengthening, and then deterioration. With the increase of temperature, the compressive strength increases and then decreases, while the splitting tensile strength decreases continuously, and the decrease is greater. Under the combined effect of the two factors, three damage modes of compressive and split tensile were analysed. Finally, the uniaxial compression constitutive model and the formula for the attenuation change of mechanical properties of nano-modified ceramic concrete were fitted based on the test data under dry and wet cycles and temperature.

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Aydan, Ömer. « Constitutive laws ». Dans Continuum and Computational Mechanics for Geomechanical Engineers, 43–79. Boca Raton : CRC Press, [2021] | Series : ISRM book series, 2326-6872 ; volume 7 : CRC Press, 2021. http://dx.doi.org/10.1201/9781003133995-5.

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Telle, Åshild, Samuel T. Wall et Joakim Sundnes. « Modeling Cardiac Mechanics on a Sub-Cellular Scale ». Dans Modeling Excitable Tissue, 28–43. Cham : Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-61157-6_3.

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Abstract We aim to extend existing models of single-cell mechanics to the EMI framework, to define spatially resolved mechanical models of cardiac myocytes embedded in a passive extracellular space. The models introduced here will be pure mechanics models employing fairly simple constitutive laws for active and passive mechanics. Future extensions of the models may include a coupling to the electrophysiology and electro-diffusion models described in the other chapters, to study the impact of spatially heterogeneous ion concentrations on the cell and tissue mechanics.

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Krausz, A. S., et K. Krausz. « Deterministic fracture kinetics theory and constitutive laws ». Dans Mechanical Behavior of Materials, 23–94. Dordrecht : Springer Netherlands, 1988. http://dx.doi.org/10.1007/978-94-009-1381-3_2.

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Krausz, A. S., et K. Krausz. « Probabilistic fracture kinetics theory and constitutive laws ». Dans Mechanical Behavior of Materials, 95–136. Dordrecht : Springer Netherlands, 1988. http://dx.doi.org/10.1007/978-94-009-1381-3_3.

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Conrad, H., W. D. Cao et A. F. Sprecher. « Constitutive laws pertaining to electroplasticity in Metals ». Dans Mechanical Behavior of Materials, 305–11. Dordrecht : Springer Netherlands, 1990. http://dx.doi.org/10.1007/978-94-009-1968-6_35.

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Eschenauer, H., N. Olhoff et W. Schnell. « Constitutive laws of linearly elastic bodies ». Dans Applied Structural Mechanics, 31–39. Berlin, Heidelberg : Springer Berlin Heidelberg, 1997. http://dx.doi.org/10.1007/978-3-642-59205-8_5.

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Takamizawa, Keiichi, et Kozaburo Hayashi. « Constitutive Law of the Arterial Wall and Stress Distribution ». Dans Computational Mechanics ’86, 829–34. Tokyo : Springer Japan, 1986. http://dx.doi.org/10.1007/978-4-431-68042-0_118.

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Actes de conférences sur le sujet "Mechanical constitutive law"

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Nerilli, Francesca, Sonia Marfia et Elio Sacco. « Tensile constitutive law of FRCM composites : A micro-mechanical modelling approach ». Dans INTERNATIONAL CONFERENCE OF NUMERICAL ANALYSIS AND APPLIED MATHEMATICS ICNAAM 2019. AIP Publishing, 2020. http://dx.doi.org/10.1063/5.0026940.

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Carmai, J., et F. P. E. Dunne. « Analysis of Consolidation of Matrix-Coated Fibre Composite by Power Law Creep ». Dans ASME 2005 International Mechanical Engineering Congress and Exposition. ASMEDC, 2005. http://dx.doi.org/10.1115/imece2005-80691.

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The paper is concerned with the establishment of constitutive modelling approach for analysis of the consolidation processing of matrix-coated fibre composites. The constitutive modeling approach makes use of a repeating unit cell technique and is based on a variational method employing Hill’s minimum principle for velocities. In addition, the existing porous material model is adopted for generalisation of the resulting constitutive equations to make it applicable to practical consolidation process in which the stress states are mutiaxial. The model requires only the creep properties of matrix material. It has been verified by comparing predicted results with those obtained from independently developed micromechanical models. The resulting constitutive model has been used to simulate the uniaxial consolidation experiment. Good comparison has been achieved.

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Di Gennaro, L., F. Daghia, M. Olive, F. Jacquemin et D. Espinassou. « A Mechanism-based Thermo-Viscoelastic Constitutive Law for Fiber Reinforced Polymer Matrix Composites ». Dans VIII Conference on Mechanical Response of Composites. CIMNE, 2021. http://dx.doi.org/10.23967/composites.2021.023.

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Mazilu, N., T. A. Conway et J. Vossoughi. « Tensorial Character of Stress or Strain and the Experimental Constitutive Equation ». Dans ASME 1996 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 1996. http://dx.doi.org/10.1115/imece1996-1136.

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Abstract The well known classical approach of tensorial constitutive laws, in the isotropic case, shows a quadratic constitutive law as a possible relation between stress and strain tensors [1]. This law is obtained as a direct consequence of the Hamilton-Cayley theorem for 3 × 3 matrices and the hypothesis of existence of an energy function [2]. Now, from the experimental point of view, the most reliable facts are, undoubtedly, those related to uniaxial loading tests. These experiments only indicate a certain functionality between stress and strain, having usually a representation by integral functions. Such a representation is quadratic only in special cases, and these cases are extremely useful in discerning some special materials.

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Jomaa, Walid, Monzer Daoud, Victor Songmene, Philippe Bocher et Jean-François Châtelain. « Identification and Validation of Marusich’s Constitutive Law for Finite Element Modeling of High Speed Machining ». Dans ASME 2014 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/imece2014-39503.

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This study aims to identify the coefficients of Marusich’s constitutive equation (MCE) for the aluminum AA7075-T651. Material constants were identified inversely form orthogonal machining tests and from dynamic tests. The proposed material model was successfully implemented in a finite element model (FEM) to simulate the high speed machining of the aluminum AA7075-T6. Deform 2D® software was used. A reasonable agreement between predictions and experiments was obtained. The comparison was based on cutting forces, chip morphology, and tool/chip contact length.

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Gray, Jessica, Soheil Fatehiboroujeni et Sachin Goyal. « Robustness Analysis of Algorithms to Estimate Constitutive Laws of Biological Filaments ». Dans ASME 2015 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/imece2015-52113.

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The structure-function relationship of biological filaments is greatly impacted by their mesoscale mechanics that involves twisting and bending deformations. For example, the mechanics of DNA looping is a key driver in gene regulation. The continuum-rod models have emerged as efficient tools for simulating the nonlinear dynamics of such deformations. However, there is no direct way to derive or measure the constitutive law of biological filaments for their continuum modeling. Therefore, it is an active area of research to develop inverse algorithms based on a continuum rod model that can estimate the constitutive law from the atomistic configurations of the filament. This paper presents a set of such algorithms that can use data from the dynamic states of deformation obtained from atomistic simulations or other sources. Depending on the kinematic quantities that are computed from the configuration data, the inverse algorithms differ in their steps to estimate the internal restoring moments and forces. The paper investigates and compares the robustness of these inverse algorithms accounting for the effect of noise in the data.

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Godfrey, Thomas A., et John N. Rossettos. « On a Constitutive Model for Twisted Hybrid Yarns ». Dans ASME 2000 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2000. http://dx.doi.org/10.1115/imece2000-1193.

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Abstract A simple micromechanical model is developed for the interactions in a parallel square-stacked mixed array of elastic fibers representing the microstructure of a hybrid yarn undergoing axial extension. The mixed array consists of a small fraction of relatively high-modulus, low-elongation-to-break (LE) fibers dispersed among high-elongation-to-break (HE) fibers. The LE fibers are assumed to break into fragments, and the LE fiber fragments are assumed to slip relative to neighboring fibers in regions near the fragment tips. The fiber array experiences lateral compression arising from the remote tension on the twisted yarn, and frictional forces acting at slipping fiber-to-fiber contact surfaces are assumed to obey Amontons’ Law. Solutions of a dimensionless boundary value problem for deformations in a unit cell of the fiber array are presented. Dimensionless parameters involving the constituent LE and HE fiber properties are identified and their influence on hybrid yarn tensile behavior is illustrated.

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Mae, Hiroyuki. « Simulation of Fracture Behavior of Elastomer Modified Polypropylene Based on Elastoviscoplastic Constitutive Equation With Craze and Tensile Softening Law ». Dans ASME 2005 International Mechanical Engineering Congress and Exposition. ASMEDC, 2005. http://dx.doi.org/10.1115/imece2005-79161.

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The strong strain-rate dependence, neck propagation and craze evolution characterize the large plastic deformation and fracture behavior of polymer. In the latest study, Kobayashi, Tomii and Shizawa suggested the elastoviscoplastic constitutive equation based on craze evolution and annihilation and then applied it to the plane strain issue of polymer. In the previous study, the author applied their suggested elastoviscoplastic constitutive equation with craze effect to the three dimensional shell issue and then showed that the load displacement history was in good agreement with the experimental result including only microscopic crack such as craze. For the future industrial applications, the macroscopic crack had to be taken into account. For instance, an airbag deployment simulation needed the macroscopic crack prediction. Thus, the main objective of this study was to propose the tensile softening equation and then add it to the elastoviscoplastic constitutive equation with craze effect so that the load displacement history could be roughly simulated during the macroscopic crack propagation. The tested material in this study was the elastomer blended polypropylene used in the interior and exterior of automobiles. First, the material properties were obtained based on the tensile test results at wide range of strain rates: 10−4 – 102 (1/sec). Next, the fast compact tension test was conducted and then the tensile softening parameters were fixed. Then, the fast bending test and the dart impact test were carried out in order to obtain the load displacement history and also observe the macroscopic crack propagation at high strain rate. Finally, the fracture behavior was simulated and then compared with the experimental results. It was shown that the predictions of the constitutive equation with the proposed tensile softening equation were in good agreement with the experimental results.

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Hosseini Farid, Mohammad, Mohammadreza Ramzanpour, Mariusz Ziejewski et Ghodrat Karami. « A Biphasic Viscoelastic Constitutive Model for Brain Tissue ». Dans ASME 2019 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/imece2019-10743.

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Abstract In this study, a rate-dependent biphasic model will be introduced to account for phenomenological behavior of brain tissue. For this purpose, a poro-hyper viscoelastic constitutive model is developed. The tissue is treated as a fluid-saturated porous medium, modeled as biphasic matter constituting of a solid matrix and interstitial liquids fill the porous spaces. The interactions between the two phases are assumed to be governed by Darcy’s law. This suggested model is calibrated with the experimental results of the bovine brain tissue, tested under high deformation rates (10, 100, 1000 mm/sec). The model will successfully take care of the detailed mechanical responses for solid and fluid phases, and their contributions to morphological behavior of this biological tissue. The material parameters of the model have been examined to agree well (R2 ≥ 0.96, where R is the coefficient of determination) with various deformation rates. In addition to representing the complete mechanical response and deformation of the solid phase, this biphasic model demonstrates the flow and diffusion of the liquid through the tissue networks.

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Smith, Joseph L. « Early Introduction of Entropy Concepts in the First Undergraduate Course in Thermodynamics ». Dans ASME 1996 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 1996. http://dx.doi.org/10.1115/imece1996-0285.

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Abstract A new introductory course in mechanical engineering thermodynamics is described. The course develops the basic concepts as natural extensions of the students previous experience. The first law and the second law are developed simultaneously and with equal emphasis. Entropy, entropy transfer and entropy generation are introduced in a manner analogous to the introduction of energy, energy transfer and generation of heat. Extensive use is made of isolated systems for analysis so that all relevant relations are systematically identified. The PVT, energy and entropy constitutive relations for subsystems are presented separately from the first law and second law relations for a given problem. With the early introduction of entropy, all of the constitutive relations, including entropy, are described at the same time. The concept of mechanical-to-thermal cross coupling within the constitutive relations is introduced and related to the Maxwell-relation partial derivatives. The energy conversion requirement for cross coupling is developed. Control volume and flow system relations are developed from closed system relations in a conventional manner. The course ends with a description of the models for several important energy conversion plants and a discussion of the reason that all practical plants are flow systems.

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Rapports d'organisations sur le sujet "Mechanical constitutive law"

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Soret, Clement, Melissandre Bonnaudet et Mures Zarea. PR-306-143732-R01 Adv Material Charact of Dent and Gouge Samples Imprvd Strain Eval. Chantilly, Virginia : Pipeline Research Council International, Inc. (PRCI), décembre 2018. http://dx.doi.org/10.55274/r0011544.

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This report provides a more accurate micro-hardness vs. strain correlation based on the larger strains achievable with interrupted tensile tests on notched specimens from two modern steels des-ignated as Pipe #1 and Pipe #2 and two vintage steels designated as Pipe #3 and Pipe #4. These pipes were used to evaluate the mechanical strength of dent and gouge defects in PRCI projects MD-4-1, MD-4-6 and DOT #339. Interrupted tensile tests were performed on specimens with dif-ferent geometries, which allowed to identify accurate parameters for a constitutive mechanical be-havior law that represents both pipe materials. Then FE numerical simulation was used to determine plastic strains levels from diameter reduction of the specimens observed during interrupted tensile tests.

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GAO, Yang, Gang SHI, Xun WANG et Yong ZHANG. MECHANICAL PROPERTY AND CONSTITUTIVE MODELING OF LOW YIELD POINT STEELS. The Hong Kong Institute of Steel Construction, décembre 2018. http://dx.doi.org/10.18057/icass2018.p.037.

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Kollegal, M., S. N. Chatterjee et G. Flanagan. Progressive Failure Analysis of Plain Weaves Using Damage Mechanics Based Constitutive Laws. Fort Belvoir, VA : Defense Technical Information Center, janvier 2006. http://dx.doi.org/10.21236/ada449264.

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Lever, James, Emily Asenath-Smith, Susan Taylor et Austin Lines. Assessing the mechanisms thought to govern ice and snow friction and their interplay with substrate brittle behavior. Engineer Research and Development Center (U.S.), décembre 2021. http://dx.doi.org/10.21079/1168142742.

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Sliding friction on ice and snow is characteristically low at temperatures common on Earth’s surface. This slipperiness underlies efficient sleds, winter sports, and the need for specialized tires. Friction can also play micro-mechanical role affecting ice compressive and crushing strengths. Researchers have proposed several mechanisms thought to govern ice and snow friction, but directly validating the underlying mechanics has been difficult. This may be changing, as instruments capable of micro-scale measurements and imaging are now being brought to bear on friction studies. Nevertheless, given the broad regimes of practical interest (interaction length, temperature, speed, pressure, slider properties, etc.), it may be unrealistic to expect that a single mechanism accounts for why ice and snow are slippery. Because bulk ice, and the ice grains that constitute snow, are solids near their melting point at terrestrial temperatures, most research has focused on whether a lubricating water film forms at the interface with a slider. However, ice is extremely brittle, and dry-contact abrasion and wear at the front of sliders could prevent or delay a transition to lubricated contact. Also, water is a poor lubricant, and lubricating films thick enough to separate surface asperities may not form for many systems of interest. This article aims to assess our knowledge of the mechanics underlying ice and snow friction.

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Kinikles, Dellena, et John McCartney. Hyperbolic Hydro-mechanical Model for Seismic Compression Prediction of Unsaturated Soils in the Funicular Regime. Pacific Earthquake Engineering Research Center, University of California, Berkeley, CA, décembre 2022. http://dx.doi.org/10.55461/yunw7668.

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A semi-empirical elasto-plastic constitutive model with a hyperbolic stress-strain curve was developed with the goal of predicting the seismic compression of unsaturated sands in the funicular regime of the soil-water retention curve (SWRC) during undrained cyclic shearing. Using a flow rule derived from energy considerations, the evolution in plastic volumetric strain (seismic compression) was predicted from the plastic shear strains of the hysteretic hyperbolic stress-strain curve. The plastic volumetric strains are used to predict the changes in degree of saturation from phase relationships and changes in pore air pressure from Boyle’s and Henry’s laws. The degree of saturation was used to estimate changes in matric suction from the transient scanning paths of the SWRC. Changes in small-strain shear modulus estimated from changes in mean effective stress computed from the constant total stress and changes in pore air pressure, degree of saturation and matric suction, in turn affect the hyperbolic stress-strain curve’s shape and the evolution in plastic volumetric strain. The model was calibrated using experimental shear stress-strain backbone curves from drained cyclic simple shear tests and transient SWRC scanning path measurements from undrained cyclic simple shear tests. Then the model predictions were validated using experimental data from undrained cyclic simple shear tests on unsaturated sand specimens with different initial degrees of saturation in the funicular regime. While the model captured the coupled evolution in hydro-mechanical variables (pore air pressure, pore water pressure, matric suction, degree of saturation, volumetric strain, effective stress, shear modulus) well over the first 15 cycles of shearing, the predictions were less accurate after continued cyclic shearing up to 200 cycles. After large numbers of cycles of undrained shearing, a linear decreasing trend between seismic compression and initial degree of saturation was predicted from the model while a nonlinear increasing-decreasing trend was observed in the cyclic simple shear experiments. This discrepancy may be due to not considering post shearing reconsolidation in the model, calibration of model parameters, or experimental issues including a drift in the position of the hysteretic shear-stress strain curve. Nonetheless, the trend from the model is consistent with predictions from previously- developed empirical models in the funicular regime of the SWRC. The developments of the new mechanistic model developed in this study will play a key role in the future development of a holistic model for predicting the seismic compression across all regimes of the SWRC.

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