In the structural design of the high pier,in order to analyze the strength and structure stability,the pier was often considered a thin-walled structure.Elastoplastic incremental theory was used to establish the model...In the structural design of the high pier,in order to analyze the strength and structure stability,the pier was often considered a thin-walled structure.Elastoplastic incremental theory was used to establish the model of elastoplastic stability of high pier.By considering the combined action of pile,soil and pier together,the destabilization bearing capacity was calculated by using 3-D finite element method(3-D FEM) for piers with different pile and section height.Meanwhile,the equivalent stress in different sections of pier was computed and the processor of destabilization was discussed.When the pier is lower,the bearing capacity under mutual effect of pile,soil and pier is less than the situation when mutual effect is not considered;when the pier is higher,their differences are not conspicuous.Along with the increase of the cross-sectional height,the direction of destabilization bearing capacity is varied and the ultimate capacity is buildup.The results of a stability analysis example are almost identical with the practice.展开更多
A unified constitutive model is proposed to describe the mechanical behavior of weak sandstone at different time scales.The instantaneous behavior of this material is characterized by the Drucker-Prager elastoplastic ...A unified constitutive model is proposed to describe the mechanical behavior of weak sandstone at different time scales.The instantaneous behavior of this material is characterized by the Drucker-Prager elastoplastic model,while the time-dependent deformation is described in terms of the microstructure evolution.This evolution is numerically simulated by progressive degradation of the elastic modulus and failure strength of the material.The proposed model is used to simulate the instantaneous triaxial compression and the multi-loading creep tests.Generally,good concordance is obtained between numerical simulations and experimental data.The proposed model is capable of describing the main features of these rocks,particularly irreversible deformations,pressure dependency,volumetric transition between compaction and dilatancy,and creep behavior.展开更多
The anomalous nonlinear elastic, perfectly plastic response behaviors of circular plate subjected to short transverse pulse load is studied. The plate is assumed fixed-pin along the boundary. 'Anomalous' here ...The anomalous nonlinear elastic, perfectly plastic response behaviors of circular plate subjected to short transverse pulse load is studied. The plate is assumed fixed-pin along the boundary. 'Anomalous' here means that the final deflection may be in the direction opposite that of the load. It has been found by detailed numerical analyses that there exists anomalous response in some narrow loading ranges, so called slots. By further calculations it is shown that this special dynamic behavior is related to coupling affects of internal forces and large plastic deformation after removal loading. Further plastic dissipation will be lead to anomalous dynamic response. This phenomena could be considered as the coupling of the geometry nonlinearity, material nonlinearity,elastic effects and the irrecoverable of the plastic deformation.展开更多
An exploratory discussion is presented on the application of egg-shaped function in elasto-plastic constitutive analysis for soft clay.Two main tasks of the paper are:1)to propose a complete yield criterion based on e...An exploratory discussion is presented on the application of egg-shaped function in elasto-plastic constitutive analysis for soft clay.Two main tasks of the paper are:1)to propose a complete yield criterion based on egg-shaped function and supplement its definition in the deviatoric section,and then a yield criterion suitable for 3D stress conditions is obtained;2)to elaborate its numerical implementation based on the drained triaxial tests.During the above discussion,a non-associated flow rule is proposed,in which the stress-dilatancy relationship in most classical theory is replaced by a linear dependence between the stress state parameterηand the rotation angleγof the plastic potential surface.Thereafter,isotropic and kinematic hardening behavior is considered by employing the hardening parameter H,which can be expressed as the function of plastic work Wp.Finally,comparisons between numerical results and test data on Taizhou soft clay are made to verify the effectiveness of the proposed model.展开更多
基金Project(06JJ5080) supported by the Hunan Natural Science Foundation of ChinaProject(05026B) supported by the Young Science Foundation of Central South University of Forestry and Technology
文摘In the structural design of the high pier,in order to analyze the strength and structure stability,the pier was often considered a thin-walled structure.Elastoplastic incremental theory was used to establish the model of elastoplastic stability of high pier.By considering the combined action of pile,soil and pier together,the destabilization bearing capacity was calculated by using 3-D finite element method(3-D FEM) for piers with different pile and section height.Meanwhile,the equivalent stress in different sections of pier was computed and the processor of destabilization was discussed.When the pier is lower,the bearing capacity under mutual effect of pile,soil and pier is less than the situation when mutual effect is not considered;when the pier is higher,their differences are not conspicuous.Along with the increase of the cross-sectional height,the direction of destabilization bearing capacity is varied and the ultimate capacity is buildup.The results of a stability analysis example are almost identical with the practice.
基金Project(51409261)supported by the National Natural Science Foundation of ChinaProjects(ZR2014EEQ014)supported by the Natural Science Foundation of Shandong Province,ChinaProjects(16CX05002A,15CX05039A)supported by the Fundamental Research Funds for the Central Universities of China
文摘A unified constitutive model is proposed to describe the mechanical behavior of weak sandstone at different time scales.The instantaneous behavior of this material is characterized by the Drucker-Prager elastoplastic model,while the time-dependent deformation is described in terms of the microstructure evolution.This evolution is numerically simulated by progressive degradation of the elastic modulus and failure strength of the material.The proposed model is used to simulate the instantaneous triaxial compression and the multi-loading creep tests.Generally,good concordance is obtained between numerical simulations and experimental data.The proposed model is capable of describing the main features of these rocks,particularly irreversible deformations,pressure dependency,volumetric transition between compaction and dilatancy,and creep behavior.
基金This project is supported by National Natural Science Foundation(10172063) of China and Shanxi Province Natural Science Foundation(20041004).
文摘The anomalous nonlinear elastic, perfectly plastic response behaviors of circular plate subjected to short transverse pulse load is studied. The plate is assumed fixed-pin along the boundary. 'Anomalous' here means that the final deflection may be in the direction opposite that of the load. It has been found by detailed numerical analyses that there exists anomalous response in some narrow loading ranges, so called slots. By further calculations it is shown that this special dynamic behavior is related to coupling affects of internal forces and large plastic deformation after removal loading. Further plastic dissipation will be lead to anomalous dynamic response. This phenomena could be considered as the coupling of the geometry nonlinearity, material nonlinearity,elastic effects and the irrecoverable of the plastic deformation.
基金Project(41672264)supported by the National Natural Science Foundation of ChinaProject(2019C03103)supported by the Key Research and Development Program of Zhejiang Province,China。
文摘An exploratory discussion is presented on the application of egg-shaped function in elasto-plastic constitutive analysis for soft clay.Two main tasks of the paper are:1)to propose a complete yield criterion based on egg-shaped function and supplement its definition in the deviatoric section,and then a yield criterion suitable for 3D stress conditions is obtained;2)to elaborate its numerical implementation based on the drained triaxial tests.During the above discussion,a non-associated flow rule is proposed,in which the stress-dilatancy relationship in most classical theory is replaced by a linear dependence between the stress state parameterηand the rotation angleγof the plastic potential surface.Thereafter,isotropic and kinematic hardening behavior is considered by employing the hardening parameter H,which can be expressed as the function of plastic work Wp.Finally,comparisons between numerical results and test data on Taizhou soft clay are made to verify the effectiveness of the proposed model.
