Shear Stress Concentration Research Articles

Finite element optimization of sample geometry for measuring the torsional shear strength of glass/metal joints

Assessment of mechanical properties of glass/metal joints is a challenging process, especially when the application relevant conditions of the joints have to be considered in the test design. In this study, a finite element method (FEM) is implemented to analyze a torsional shear strength test designed for glass-ceramic/steel joints aiming towards solid oxide fuel/electrolysis cells application. Deviations from axial symmetry of the square flanges (ends) of respective hourglass-shaped specimens and also supporting and loading sockets of the test set-up are included in the model to simulate conditions close to reality. Undesirable tensile stress and also shear stress concentration appear at the outer edge of glass-ceramic layers, which are less for the hollow-full specimen. The simulation results show that for a specimen with either 9 mm thick square- or 6 mm thick triangular-flanges, locally enhanced tensile stresses almost disappear, resulting in a symmetric shear stress distribution. The difference between the analytically derived nominal shear strength and the real critical shear stress derived via simulation reduces with decreasing the fracture torque.

Fatigue failure investigation of pultruded GFRP pre-tightened single-tooth connector (PTSTC)

The clamping force perpendicular to the fiber has a significant and complex effect on the fatigue behavior of the composite mechanical joint. In this paper, the pultrusion glass fiber reinforced polymer (GFRP) plate was selected, and the fatigue test (R = 0.1) was conducted to study the effect of clamping stress on the fatigue failure mode of the pre-tightening single tooth connector (PTSTC).The fatigue-test results show that reducing the maximum cyclic stress could increase the life under the same pre-tightening stress. Numerical analysis shown that under the same maximum cyclic stress, the shear stress concentration along the tooth-root plane decreased with the increase of pre-tightening stress. Therefore, the fatigue life corresponding to the interlaminar shear failure also increased. However, above a certain pre-tightening stress level, the life improvement discontinued because the failure mode changed from interlaminar shear failure on the tooth-root plane to fiber failure on the tooth groove. This phenomenon was verified using the Puck's fiber failure criterion. In addition, the numerical analysis results show that the tensile and transverse shear stress concentrations on the cross section in the tooth groove were more severe as the pre-tightening stress increased. Therefore, the fatigue life corresponding to the fiber failure also decreased. In summary, choosing an appropriate pre-tightening stress is critical to the fatigue design of GFRP PTSTCs.

Stress Fields at the Central Point of Arc Crack under Uniaxial Tension

In this study the stress fields under uniaxial tension of the plane with arc cut were calculated. To describe the concentration of normal and shear stresses in the areas of the crack ends, new characteristics based on equilibrium conditions were introduced. The influence of the angle of the crack arc opening and the direction of the plane tension was studied. It was found that those factors changed the value and the stresses sign at the crack ends. The opening angles of arc cracks and tension direction promoting the development of cracks under the influence of tensile strain, tensile stresses or combination of the stresses were determined. The promoting conditions that inhibit the cracks were studied. Copyright © VBRI Press.

Flow-splitting-based computation of outlet boundary conditions for improved cerebrovascular simulation in multiple intracranial aneurysms.

Image-based hemodynamic simulations have great potential for precise blood flow predictions in intracranial aneurysms. Due to model assumptions and simplifications with respect to boundary conditions, clinical acceptance remains limited. Within this study, we analyzed the influence of outflow-splitting approaches on multiple aneurysm studies and present a new outflow-splitting approach that takes the precise morphological vessel cross sections into account. We provide a detailed comparison of five outflow strategies considering eight intracranial aneurysms: zero-pressure configuration (1), a flow splitting inspired by Murray's law with a square (2) and a cubic (3) vessel diameter, a flow splitting incorporating vessel bifurcations based on circular vessel cross sections (4) and our novel flow splitting including vessel bifurcations and anatomical vessel cross sections (5). Other boundary conditions remain constant. For each simulation and each aneurysm, we conducted an evaluation based on common hemodynamic parameters, e.g., normalized wall shear stress and inflow concentration index. The comparison of five outflow strategies for image-based simulations shows a large variability regarding the parameters of interest. Qualitatively, our strategy based on anatomical cross sections yields a more uniform flow rate distribution with increased aneurysm inflow rates. The commonly used zero-pressure approach shows the largest variations, especially for more distal aneurysms. A rank ordering of multiple aneurysms in one patient might still be possible, since the ordering appeared to be independent of the outflow strategy. The results reveal that outlet boundary conditions have a crucial impact on image-based blood flow simulations, especially for multiple aneurysm studies. We could confirm the advantages of the more complex outflow-splitting model (4) including an incremental improvement (5) compared to strategies (1), (2) and (3) for this application scenario. Furthermore, we discourage from using zero-pressure configurations that lack a physiological basis.

Development of an in vitro media perfusion model of Leishmania major macrophage infection.

BackgroundIn vitro assays are widely used in studies on pathogen infectivity, immune responses, drug and vaccine discovery. However, most in vitro assays display significant differences to the in vivo situation and limited predictive properties. We applied medium perfusion methods to mimic interstitial fluid flow to establish a novel infection model of Leishmania parasites.MethodsLeishmania major infection of mouse peritoneal macrophages was studied within the Quasi Vivo QV900 macro-perfusion system. Under a constant flow of culture media at a rate of 360μl/min, L. major infected macrophages were cultured either at the base of a perfusion chamber or raised on 9mm high inserts. Mathematical and computational modelling was conducted to estimate medium flow speed, shear stress and oxygen concentration. The effects of medium flow on infection rate, intracellular amastigote division, macrophage phagocytosis and macropinocytosis were measured.ResultsMean fluid speeds at the macrophage cell surface were estimated to be 1.45 x 10−9 m/s and 1.23 x 10−7 m/s for cells at the base of the chamber and cells on an insert, respectively. L. major macrophage infection was significantly reduced under both media perfusion conditions compared to cells maintained under static conditions; a 85±3% infection rate of macrophages at 72 hours in static cultures compared to 62±5% for cultures under slow medium flow and 55±3% under fast medium flow. Media perfusion also decreased amastigote replication and both macrophage phagocytosis (by 44±4% under slow flow and 57±5% under fast flow compared with the static condition) and macropinocytosis (by 40±4% under slow flow and 62±5% under fast flow compared with the static condition) as measured by uptake of latex beads and pHrodo Red dextran.ConclusionsPerfusion of culture medium in an in vitro L. major macrophage infection model (simulating in vivo lymphatic flow) reduced the infection rate of macrophages, the replication of the intracellular parasite, macrophage phagocytosis and macropinocytosis with greater reductions achieved under faster flow speeds.

Shear stress concentrations in tramway rails: Results from beam theory-based cross-sectional 2D Finite Element analyses

During their lifetimes, tramway networks become increasingly susceptible to mechanical damage in the form of rail fractures. Understanding the underlying reasons, and initiating appropriate countermeasures may be facilitated by (computational) modeling tools. The development of such tools calls for a sound theoretical foundation. The latter is still largely missing, as the cross-sectional shapes of grooved rails employed in tramway networks differ significantly from those of (in this regard) well-investigated railroad systems. As a first step towards closing this knowledge gap, we here report on a novel beam theory approach allowing to compute typical shear stress distributions throughout the cross sections of grooved rails. Based on classical concepts, such as Bernoulli and Saint-Venant beam kinematics, cross-sectional boundary value problems for the related shear stress distributions are derived, and corresponding solutions are obtained in the form of 2D Finite Element approximations. This way, it is revealed that practically relevant loading scenarios induce distinctive shear stress concentrations. Remarkably, the positions of the latter agree well with fracture patterns observed in situ.

Simulation of failure processes of as-cast Ti-5Al-5Nb-1Mo-1V-1Fe titanium alloy subjected to quasi-static uniaxial tensile testing

A three-dimensional (3D) microscopic structural finite element model reflecting the realistic pore distribution of as-cast Ti-5Al-5Nb-1Mo-1V-1Fe titanium alloy was built through micro-computed tomography (micro-CT). The model was then introduced into ANSYS LS-DYNA software to investigate the 3D spatial evolution process of damage and failure under quasi-static uniaxial tension. To validate the simulation results, we tested the uniaxial tensile responses of Ti-5Al-5Nb-1Mo-1V-1Fe and quantitatively characterized the tensile fracture morphology with a 3D profilometer. To reveal the underlying mechanism of damage and failure, we took the triaxiality of Rσ into consideration. Local principal stress concentration was found to exist around two micro-pores at the initial stage, thus inducing two crack sources; as the load increased, more crack sources were generated and steadily propagated through void growth and coalescence under the influence of multiaxial principal stress concentration, thus leading to the local tensile failure of the model. When cracks reached a critical size, the shear stress concentration became the dominant factor affecting failure, thus inducing severe effective plastic strain between cracks. The cracks rapidly connected through plastic slip and cleavage, thereby resulting in the final shear failure of the model. The simulation results were in good agreement with the observed experimental results.

Analysis of the stress state at the double-step joint in heavy timber structures

The double-step joint is among the most frequently used layouts, within carpentry joints, for transmitting higher forces that would allow a single notch. They are especially effective in heavy timber structures. Nowadays, computer-aided manufacturing is being used more often, demanding further progress in its understanding. The conventional design of these joints is conducted by using simplifying assumptions, in particular regarding the shear stress distribution. This is overcome by the use of strength reduction coefficient, which is currently under study. Numerical simulation and experimental tests were carried out with heavy timber cross-sections for rafter to tie-beam truss joint. They were manufactured in glue-laminated timber owing to the large cross-sections tested. Experimental load-strain and load-displacement diagrams were compared with numerical results. This allowed observing the great shear stress concentration produced in the failure by shear crack, which suggests the application of conservative shear strength reduction coefficients.

Erosion control of hedgerows under soils affected by disturbed soil accumulation in the slopes of loess plateau, China

Soil erosion on disturbed soil accumulations severely threatens the ecological stability of construction sites and their surrounding areas. This study aims to quantify the effects of hedgerows on the hydraulic characteristics of runoff and understand the mechanism of runoff and sediment reduction of hedgerow slopes. A field scouring-erosion experiment was conducted on a typical spoiled ground in “Changwu Agricultural Ecological Experimental Station” of the Loess Plateau in China to explore the effects of hedgerows on erosion control in slopes of disturbed soil accumulation. In experiments, 6 plots, which consisted of three hedgerow plots (H) and three control plots of bare slope (C), with a uniform size of 20 m, 5 m width, and 0.5 m height were constructed with excavated soil. By using three different flow discharges (35, 45, and 55 L/min) on the slope with three different gradients (24°, 28° and 32°), some essential parameters, rate of sediment yield, sediment concentration of runoff, sediment reduction, shear stress, denudation rate, and runoff power, were measured for mechanism analysis. The hedgerows could delay runoff, which meant the initial runoff time of hedgerows obviously lagged behind the control plot about 1–8 min. The capability of runoff generating control by the hedgerows depended on the duration of discharge, which grew first and reduced later. At the later stage, the sediment concentration in the runoff of the hedgerow plots exceeded the control plots, which could be related to transformation of hedgerows between source and sink. The accumulated sediment yields of the hedgerow plots were reduced by 10–45% compared to the control plots. The relationship of the reduction of accumulated sediment yield and duration of discharge could be stated with quadratic function (P < 0.01), which indicated critical runoff time was advanced with increase of slope and flow discharge. Based on the runoff power, the soil erodibility parameter of the hedgerow slopes (3.58 g∙N−1∙m−1) was larger than that of the control slopes (2.83 g∙N−1∙m−1). Hedgerows could hinder soil transport, which not only reduced soil peeling, increased critical shear stress, and critical runoff power but also curbed rill evolution in the lower slope erosion process. The important parameters from this study would be helpful for optimal allocation of hedgerow measures, erosion control and erosion prediction model establishment on disturbed soil accumulation.

The effects of the rock bridge ligament angle and the confinement on crack coalescence in rock bridges: An experimental study and discrete element method

The present article investigates the influences of the rock bridge ligament angle, β, and the confinement on crack coalescence patterns by conducting laboratory and numerical tests on rock-like specimens. Laboratory tests show that no coalescence in the rock bridge occurred for low β. With an increase of β, tensile-shear coalescence and tensile coalescences subsequently occurred. In addition, the increase in the confinement first promoted shear coalescence and then restrained crack coalescence for low β, whereas the tensile coalescence was restrained by the increase in confinement for high β. The numerical results corroborate the laboratory tests in the coalescence patterns. In addition, the numerical study shows that tensile and shear cracks subsequently initiated near crack tips because of the concentrated tensile and shear stresses, respectively. Regarding the influence of β on crack coalescence, tensile or shear stress failed to concentrate in rock bridges for low β. Therefore, the cracks failed to coalesce, whereas with the increase in β, tensile and shear stress concentrations occurred in the bridge and led to either tensile shear or tensile coalescence. Regarding the influence of confinement on crack coalescence, the increase in confinement restrained the tensile stress concentrations and further hindered tensile crack coalescence in rock bridges for high values of β.

The effects of fluid shear stress and O2 concentration on the phosphorylation of eNOS at Ser635 in endothelial cells

Abstract Under hypoxic conditions, NO plays an important role in regulating O2 delivery by controlling local blood vessel relaxation. NO is primarily produced by endothelial NO synthase (eNOS), which is reportedly phosphorylated at Ser635 and thereby activated under conditions of fluid shear stress and O2 concentration. The aim of this work was to investigate the effects of fluid shear stress and O2 concentration on the phosphorylation of eNOS at Ser635. Bovine aortic endothelial cells were exposed to hypoxia only, a combination of shear stress and hyperoxia, and a combination of shear stress and hypoxia at various time points. Hypoxia did not increase phosphorylation significantly at 15 min but induced a gradual increase to 1.94-fold over 180 min. Under simultaneous exposures to shear stress and hyperoxia, eNOS phosphorylation was detected after 15-min and was 2.75-fold higher than the initial condition at the 60-min time point. In contrast, under a combination of shear stress and hypoxia, eNOS phosphorylation was increased to 2.44-fold at 60 min. However, although phosphorylation levels under these conditions were higher than those after hypoxia only at all time points, they were lower than those after a combination of shear stress and hyperoxia. Our results indicate that hyperoxia and shear stress additively stimulate phosphorylation of eNOS at Ser635 and suggest a moderating role of hypoxia.

DESIGN CALCULATION TECHNIQUE FOR THICK-WALLED COMPOSITE CONSTRUCTIONS OPERATING UNDER HIGH-SPEED LOADING

The scientific paper presents a technique for calculating a thick-walled axially symmetrical construction consisting of a steel rod (reinforcing component) and an external thick-walled shell made of carbon fiber. The construction is loaded with linear load distributed along its length, associated with the operating external pressure, and inertial forces. The technique is based on a one-dimensional model of a composite rod of variable cross-section, roughly taking into account transverse deformations, which is necessary when analyzing a thickwalled construction operating under pressure. In the proposed approach, the geometry of the product is divided into sections and approximated by fragments in the form of truncated cones and, in the particular case, in the form of cylinders. As a result of calculations, the distribution of normal tensile/compression stresses in the shell and in the reinforcing rod, as well as tangential stresses at the boundary of their contact, are determined. As a result of test calculations, a fairly good consistency of the considered one-dimensional model with refined finiteelement modeling is shown. It has been established that the concentration of shear stresses is realised due to the presence of substantially inhomogeneous deformations in the areas of sharp changes in geometry, a reduction in the radius of the shell (the appearance of edge effects), and in the area of a sharp increase in the radius of the bevel of the shell where external pressure is in place.

Реологические свойства композитов на основе гидроксида алюминия и смесей полиэтилена низкой и высокой плотности

The results of the study of the rheological characteristics of low- and high-density polyethylene blend in the ratio of 50 : 50 and its composites filled with aluminum hydroxide are presented. The influence of the concentration of aluminum hydroxide, temperature, and shear stress on the regularity of changes in the effective viscosity and shear rate has been established. Rheograms of low- and high-density polyethylene blend in the ratio of 50 : 50 and composites based on it are presented. The dependence of viscosity on temperature in Arrhenius coordinates is determined, according to which the “apparent” activation energy of viscous flow for the initial low- and high-density polyethylene blend and its composites filled with aluminum hydroxide varies in the range of 6–19 and 11–31 kJ/mol, respectively. A universal temperature-invariant characteristic of the viscosity properties of low-and high- density polyethylene blend in the ratio of 50 : 50 and its composites filled with aluminum hydroxide, which makes it possible to predict the change in the melt viscosity of composites in a wide range of shear rates and stresses, is drawn. It is shown that, with an increase in the concentration of aluminum hydroxide in the polymer mixture to 5 wt %, the value of the shear rate remains almost unchanged relative to the initial low- and high-density polyethylene blend (50/50). Rheological studies of the melt of polymer materials have been carried out in accordance with the standard ASTM D1238 on a CEAST MF50 capillary rheometer (INSTRON, Italy) in the temperature range of 190–250°C and in the load range of 3.8–21.6 kg.

High temperature tensile behavior of a thin-walled Ni based single-crystal superalloy with cooling hole: In-situ experiment and finite element calculation

The high temperature tensile behavior for film-hole plates of a Ni based single-crystal superalloy has been investigated. Both the hole and the drill-produced recast layer are detrimental to tensile properties. During yielding, the strain distribution obtained in-situ by digital image correlation technique exhibits an X-like concentration at <101> directions around the hole. The crack initiates on the hole's edge with different crystallographic directions, depending on the recast layer. The fracture mechanism for 980 °C tensile exhibits a necking-dimple process, where plastic deformation is originated from the a/2 [101](11¯1¯) dislocation's by-passing. The Peierls-Nabarro force on [101](11¯1¯) slip system is 258.7 MPa, leading to the yielding of plate-type specimen. The finite-element method results indicate an X-like concentration of the resolved shear stress for such slip system around the hole, where the stress exceeds the Peierls-Nabarro force. This results in an X-like plastic deformation during yield, which explains the in-situ experimental results. The different chemical compositions and phase structures result in the softer nature of recast layer and the special stress/strain concentrated in it. The crack initiation and propagation around the hole also investigated in detail, via combining the experimental and computational results.

A Numerical Study on Unsteady Flow of Herschel–Bulkley Nanofluid Through an Inclined Artery with Body Acceleration and Magnetic Field

The present paper deals with the mathematical model for pulsatile flow of Herschel–Bulkley fluid through an inclined artery with stenosis and tapering. The governing equations of Herschel–Bulkley nanofluid are highly non-linear which are simplified in the case of artery having mild stenosis and slightly tapering. The effects of heat and mass transfer have been considered in the model. The solutions for velocity profile, wall shear stress distribution, flow impedance, temperature and concentration profiles are evaluated numerically using finite difference schemes for different values of the parameters associated with the model. The obtained results are represented graphically and the influences of involved parameters on the flow of nanofluid are discussed in detail. It is observed from the computed numerical results that the velocity profile enhances with increase in Grashof numbers. The magnitude of shear stress at the arterial wall increases with increase in stenotic height and Hartmann number and decreases with increase in Grashof numbers. The value of flow resistance enhances with increase in stenotic height, Hartmann number, time and thermophoresis parameter and decreases with increase in inclination parameters, Grashof numbers, Brownian motion parameter and Prandtl number. The combined effects of rheology of blood and parameters associated with heat and mass transfer on flow resistance have been analysed from which the significance of rheology of blood can be understood.

Diffraction of antiplane shear waves and stress concentration in a cracked couple stress elastic material with micro inertia

We investigate diffraction of reduced traction shear waves applied at the faces of a stationary crack in an elastic solid with microstructure, under antiplane deformation. The material behaviour is described by the indeterminate theory of couple stress elasticity and the crack is rectilinear and semi-infinite. The full-field solution of the crack problem is obtained through integral transforms and the Wiener–Hopf technique. A remarkable wave pattern appears which consists of entrained waves extending away from the crack, reflected Rayleigh waves moving along the crack, localized waves irradiating from the crack-tip with, possibly, super-Rayleigh speed and body waves scattered around the crack-tip. Interestingly, the localized wave solution may be greatly advantageous for defect detection through acoustic emission. Dynamic stress intensity factors are presented, which generalize to Elastodynamics the corresponding results already obtained in the static framework. The correction brings out the important role of wave diffraction on stress concentration.

Development of a novel fatigue test method for cord-rubber composites

Fatigue testing of cord-rubber composites is of significant interest as components manufactured from these materials are typically subjected to repeated loading during service. In this work, initial fatigue tests on a single carbon cord reinforced hydrogenated nitrile butadiene rubber (CC-HNBR) model composite were undertaken using conventional wedge grips which are routinely employed for fatigue testing of cord-rubber composites. Damage evolution was monitored using thermal imaging, while post-failure modes were evaluated using scanning electron microscopy (SEM). Finite element analysis (FEA) was performed to understand the stress state in the gripping region. The observed failure mode in wedge grips based testing was found to be interfacial debonding as a consequence of shear stress concentrations induced by the grips, leading to a significant underestimation of fatigue life. Consequently, an alternative bollard based test methodology was developed for cord-rubber composites. Fatigue data generated using this novel bollard test set-up was compared with data obtained by using conventional wedge grips. Bollard-based testing resulted in tensile fatigue behaviour dominated by cord failure rather than failure by interfacial debonding during accelerated laboratory fatigue testing, making the developed test methodology better suited for the characterisation of intrinsic fatigue behaviour of cord-rubber composites.

Optimizing mechanical properties of bio-inspired composites through functionally graded matrix and microstructure design

Inspired by biological composites, the brick-and-mortar microstructure has been adopted in many synthetic composites to achieve improved material strength and toughness. Recently, introducing gradient in the matrix property is found to be a novel approach to provide additional enhancements in composites’ mechanical performance. In this study, we present a theoretical approach to investigate the mechanical properties of the brick-and-mortar composites in which the shear modulus of the matrix varies periodically. Using the parabolic distribution of the shear modulus as an example, we show that the shear stress concentration along the interface can be greatly suppressed, and the material elastic limit and resilience can be improved. Further, we identified two critical aspect ratios of the brick-and-mortar unit cell that optimize the elastic limit and resilience of composites. From analyses and numerical calculations, formulae for these two critical aspect ratios are obtained and validated by finite element simulations.

Material-tailored adhesively bonded multilayers: A theoretical analysis

Multimaterial multilayered systems such as bonded/welded joints, adhesive anchors, electronic assemblies, coatings and micro- and nano-scale fiber reinforced composites, often exhibit interfacial failure during service as they experience steep stress gradients at the interfaces. In this study, a theoretical framework for the stress analysis of material-tailored adhesively bonded multilayers is presented. Single-lap joints (SLJs) even under tensile loading undergo large lateral defection and rotation as a result of non-collinear load-path, giving rise to stress concentrations near the free edges whereas the resulting stresses in SLJs with compliance-tailored adherends are influenced by the net effect of reduced bending moment and reduction in bending stiffness of the joint. Using Euler-Bernoulli and Timoshenko beam bending theories, shear force (SF) and bending moment (BM) along the overlap length of the adherend-tailored SLJs are evaluated. Subsequently, using SF and BM obtained above as boundary conditions, a force-based sandwich model for an unbalanced joint within the context of 2D elastostatics is formulated to predict adhesive stresses. The model predictions are validated by finite element results and are found to be in good agreement. Reduction in adhesive shear and peel stress concentrations of about 46% and 42%, respectively, was observed for joints with compliance-tailored adherends at sub-critical bondlength (l=0.2lcr) relative to baseline joints, where lcr is the minimum bondlength required for a baseline joint to enable shear-dominated load transfer. At critical bondlength, i.e., l=lcr (250 mm for the parameters considered here), 89% and 68% reduction in adhesive shear and peel stress concentrations, respectively, was observed. Furthermore, the model is extended to evaluate the combined effect of compliance-tailoring of both adhesive and adherend and found reduction in adhesive shear and peel stress concentrations of about 90% and 74% respectively at l=lcr. The results of this study provide guidelines for the design of material-tailored multilayers and can be readily extended to study effect of anisotropic tailoring of adherends as the formulation allows for the variation of adherend’s modulus in both longitudinal and transverse directions.

A coupled thermal–hydraulic–mechanical–chemical (THMC) model for methane hydrate bearing sediments using COMSOL Multiphysics

Methane gas extraction by a deep well installed in methane hydrate bearing sediments (MHBS) found in deep subsea and permafrost regions is a coupled thermal–hydraulic–mechanical–chemical (THMC) process. The key processes include heat convection between layers, local deformation due to compaction, and stress relaxation caused by damage of the bonded structure. As improper production may induce formation compaction, sand production, and wellbore failures, a numerical code is needed to simulate the THMC processes during methane gas production so that geomechanics and production risks can be quantified. In this study, a nonlinear THMC model was implemented in the partial differential equations (PDE) and structural mechanics module of the COMSOL Multiphysics® finite element code. This paper describes the non-linear coupled governing equations of the mechanical behavior during hydrate dissociation. In particular, it introduces a new thermodynamics-based constitutive model to simulate the mechanical behavior of hydrate bearing sediments. The performance of the newly developed code was examined by comparing the computed results with test data and other simulation results. The differences between fully coupled and semi-coupled models were analyzed. For example, heterogeneous turbidite layers observed in the Nankai Trough were modeled, and behaviors such as heat convection between different layers, shear stress and strain concentration were examined.