In this paper,we study a porous thermoelastic problem with microtemperatures assuming parabolic higher order in time derivatives for the thermal variables.The model is derived and written as a coupled linear system.Th...In this paper,we study a porous thermoelastic problem with microtemperatures assuming parabolic higher order in time derivatives for the thermal variables.The model is derived and written as a coupled linear system.Then,a uniqueness result is proved by using the logarithmic convexity method in the case that we do not assume that the mechanical energy is positive definite.Finally,the existence of the solution is obtained by introducing an energy function and applying the theory of linear semigroups.展开更多
In the paper, we study the global existence of weak solution of the fully nonlinear parabolic problem (1.1)-(1.3) with nonlinear boundary conditions for the situation without strong absorption terms. Also, we consider...In the paper, we study the global existence of weak solution of the fully nonlinear parabolic problem (1.1)-(1.3) with nonlinear boundary conditions for the situation without strong absorption terms. Also, we consider the blow up of global solution of the problem (1.1)-(1.3) by using the convexity method.展开更多
Multi-sphere clumps are commonly used to simulate non-spherical particles in discrete element method simulations.It is of interest whether the degree of local non-convexity λ affects the mechanical behaviour of granu...Multi-sphere clumps are commonly used to simulate non-spherical particles in discrete element method simulations.It is of interest whether the degree of local non-convexity λ affects the mechanical behaviour of granular materials with the same non-convexity η.A series of discrete-element-method biaxial shear tests are conducted on rough particle packings with rη=0.075 and different λ values(ranging from 0.134 to 0.770).The microscale results show that the contact type changes with an increase in λ.However,the critical strength is independent of λ.The evaluation of the contributions of different contact types to the critical shear strength and a detailed analysis of the anisotropies help clarify the microscopic mechanisms that result in the independence of the critical shear strength from λ.展开更多
In this paper we present some results concerning the optimal shape design problem governed by the fourth-order variational inequalities. The problem can be considered as a model example for the design of the shapes fo...In this paper we present some results concerning the optimal shape design problem governed by the fourth-order variational inequalities. The problem can be considered as a model example for the design of the shapes for elastic-plastic problem. The computations are done by finite element method, and the performance criterion is minimized by the material derivative method. We also discuss the error estimates in the appropriate norm and present some numerical results. An example is used to clearly illustrate the essential elements of shape design problems.展开更多
基金part of the project(No.PID2019-105118GB-I00),funded by the Spanish Ministry of Science,Innovation and Universities and FEDER“A way to make Europe”。
文摘In this paper,we study a porous thermoelastic problem with microtemperatures assuming parabolic higher order in time derivatives for the thermal variables.The model is derived and written as a coupled linear system.Then,a uniqueness result is proved by using the logarithmic convexity method in the case that we do not assume that the mechanical energy is positive definite.Finally,the existence of the solution is obtained by introducing an energy function and applying the theory of linear semigroups.
文摘In the paper, we study the global existence of weak solution of the fully nonlinear parabolic problem (1.1)-(1.3) with nonlinear boundary conditions for the situation without strong absorption terms. Also, we consider the blow up of global solution of the problem (1.1)-(1.3) by using the convexity method.
基金financially supported by the National Natural Science Foundation of China,China(No.51809292,51478481 and 51508141)Postdoctoral Fund of Central South University,China(No.205455)Beijing Municipal Science and Technology Project:Research and Application of Design and Construction Technology of Railway Engineering Traveling the Rift Valley,China(No.Z181100003918005).
文摘Multi-sphere clumps are commonly used to simulate non-spherical particles in discrete element method simulations.It is of interest whether the degree of local non-convexity λ affects the mechanical behaviour of granular materials with the same non-convexity η.A series of discrete-element-method biaxial shear tests are conducted on rough particle packings with rη=0.075 and different λ values(ranging from 0.134 to 0.770).The microscale results show that the contact type changes with an increase in λ.However,the critical strength is independent of λ.The evaluation of the contributions of different contact types to the critical shear strength and a detailed analysis of the anisotropies help clarify the microscopic mechanisms that result in the independence of the critical shear strength from λ.
文摘In this paper we present some results concerning the optimal shape design problem governed by the fourth-order variational inequalities. The problem can be considered as a model example for the design of the shapes for elastic-plastic problem. The computations are done by finite element method, and the performance criterion is minimized by the material derivative method. We also discuss the error estimates in the appropriate norm and present some numerical results. An example is used to clearly illustrate the essential elements of shape design problems.
