In this study,a thermo-elasto-viscoplastic model for soft rock is proposed to describe its fundamental mechanical behavior of soft rock such as the influences of overconsolidation,intermediate principal stress,tempera...In this study,a thermo-elasto-viscoplastic model for soft rock is proposed to describe its fundamental mechanical behavior of soft rock such as the influences of overconsolidation,intermediate principal stress,temperature,time dependency and inherent structure with a unified set of parameters.In the model,the concepts of subloading and superloading yielding surfaces are introduced to describe the influence of overconsolidation and structure on the deformation and strength of soft rock.The influence of the intermediate principal stress is also properly considered by adopting a transformed stress tensor t_(ij).To consider the temperature effect,a thermo-induced equivalent stress is introduced to consider its influence on the yielding surfaces,the evolution of the overconsolidation,and the structure when subjected to shearing loading under different conditions.By comparing the calculated results with test results of a manmade rock under different loading and temperature conditions,the availability and accuracy of the proposed model are carefully investigated,and the performance of the proposed model is verified in detail.展开更多
A dynamic contact problem for elastic-viscoplastic materials with thermal effects is investigated. The contact is bilateral, and the friction is modeled with Tresca＇s friction law with heat exchange. A variational fo...A dynamic contact problem for elastic-viscoplastic materials with thermal effects is investigated. The contact is bilateral, and the friction is modeled with Tresca＇s friction law with heat exchange. A variational formulation of the model is derived, and the existence of a unique weak solution is proved. The proofs are based on the classical result of nonlinear first order evolution inequalities, the equations with monotone operators, and the fixed point arguments. Finally, the continuous dependence of the solution on the friction yield limit is studied.展开更多
In this paper,the thermodynamic behavior of soil was observed in well-known heating tests via a simulation,which included THMcoupled finite element analysis as the boundary value problem(BVP).The primary purpose of th...In this paper,the thermodynamic behavior of soil was observed in well-known heating tests via a simulation,which included THMcoupled finite element analysis as the boundary value problem(BVP).The primary purpose of the paper was to identify the necessity to model a phenomenon called‘the volumetric contraction of soft clay due to heating’by introducing some extra parameters in the thermoelastoplastic model in which the THM analyses were conducted.Based on the simulation,it was determined that the heating test is only a BVP,and the phenomenon is simply an average behavior of the BVP,not an inherent property of soil.Based on the universal rule that any material will expand when heated,it is not necessary to introduce an extra parameter into a properly organized thermo-elastoplastic model to describe the phenomenon.The results may provide a useful insight for researchers who are interested in modeling the thermodynamic behavior of soils.展开更多
基金the National Nature Science Foundation of China(Grant No.51608385)Nature Science Foundation of Ningbo(Grant No.2018A610230)is appreciated.Financial support from Grant-in-Aid Scientific Research(B),No.17H03304Japan Society for the Promotion of Science,is also appreciated.
文摘In this study,a thermo-elasto-viscoplastic model for soft rock is proposed to describe its fundamental mechanical behavior of soft rock such as the influences of overconsolidation,intermediate principal stress,temperature,time dependency and inherent structure with a unified set of parameters.In the model,the concepts of subloading and superloading yielding surfaces are introduced to describe the influence of overconsolidation and structure on the deformation and strength of soft rock.The influence of the intermediate principal stress is also properly considered by adopting a transformed stress tensor t_(ij).To consider the temperature effect,a thermo-induced equivalent stress is introduced to consider its influence on the yielding surfaces,the evolution of the overconsolidation,and the structure when subjected to shearing loading under different conditions.By comparing the calculated results with test results of a manmade rock under different loading and temperature conditions,the availability and accuracy of the proposed model are carefully investigated,and the performance of the proposed model is verified in detail.
文摘A dynamic contact problem for elastic-viscoplastic materials with thermal effects is investigated. The contact is bilateral, and the friction is modeled with Tresca＇s friction law with heat exchange. A variational formulation of the model is derived, and the existence of a unique weak solution is proved. The proofs are based on the classical result of nonlinear first order evolution inequalities, the equations with monotone operators, and the fixed point arguments. Finally, the continuous dependence of the solution on the friction yield limit is studied.
文摘In this paper,the thermodynamic behavior of soil was observed in well-known heating tests via a simulation,which included THMcoupled finite element analysis as the boundary value problem(BVP).The primary purpose of the paper was to identify the necessity to model a phenomenon called‘the volumetric contraction of soft clay due to heating’by introducing some extra parameters in the thermoelastoplastic model in which the THM analyses were conducted.Based on the simulation,it was determined that the heating test is only a BVP,and the phenomenon is simply an average behavior of the BVP,not an inherent property of soil.Based on the universal rule that any material will expand when heated,it is not necessary to introduce an extra parameter into a properly organized thermo-elastoplastic model to describe the phenomenon.The results may provide a useful insight for researchers who are interested in modeling the thermodynamic behavior of soils.
