In this study, an isotropic hardening constitutive model is presented to study the behavior of frozen soil under impact loading. In plasticity, a modified Drucker–Prager yield function is adopted. Based on the experi...In this study, an isotropic hardening constitutive model is presented to study the behavior of frozen soil under impact loading. In plasticity, a modified Drucker–Prager yield function is adopted. Based on the experimental investigations at different strain rates and different temperatures by means of split Hopkinson pressure bar, the Drucker–Prager criterion has been modified with consideration in the effect of strain rate, and the model parameters have been determined. Compared the constitutive model with the experimental results, the predicted tendencies of the model corresponded well to the test curves.展开更多
By taking the frozen soil as a particle-reinforced composite material which consists of clay soil （i.e., the matrix） and ice particles, a micromechanical constitutive model is established to describe the dynamic com...By taking the frozen soil as a particle-reinforced composite material which consists of clay soil （i.e., the matrix） and ice particles, a micromechanical constitutive model is established to describe the dynamic compressive deformation of frozen soil. The proposed model is constructed by referring to the debonding damage theory of composite materials, and addresses the effects of strain rate and temperature on the dynamic compressive deformation of frozen soil. The proposed model is verified through comparison of the predictions with the corresponding dynamic experimental data of frozen soil obtained from the split Hopkinson pressure bar （SHPB） tests at different high strain rates and temperatures. It is shown that the predictions agree well with the experimental results.展开更多
In this study,a series of experiments were carried out on the AZ31B magnesium alloy,including both a macro-experiment(mechanical experiment)and a micro-experiment(dislocation observation).Next,based on the considerati...In this study,a series of experiments were carried out on the AZ31B magnesium alloy,including both a macro-experiment(mechanical experiment)and a micro-experiment(dislocation observation).Next,based on the consideration of the deformation mechanism of magnesium alloys(dislocation slip and twinning),a dynamic constitutive model of the magnesium alloy was established.In the developed model,the strain-rate-sensitivity control and the effect of temperature on the dynamic mechanical performance of the alloy were also investigated.The model parameters were determined by fitting the macroscopic experimental results.Next,the evolution of the micro-deformation mechanism was calculated by the developed model,and the trend of macro-mechanical behavior was also discussed.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.11972028 and 12272328)the Development Project of Original Scientific Research Instrument of Southwest Jiaotong University(Grant No.XJ2021KJZK045)the Natural Science Foundation of Sichuan Province(Grant No.2022NSFSC0420).
基金supported by the National Natural Science Foundation of China (11172251)the Open Fund of State Key Laboratory of Frozen Soil Engineering (SKLFSE201001)the Open Research Project of State Key Laboratory of Explosion Science and Technology in Beijing Institute of Technology (KFJJ1310M)
文摘In this study, an isotropic hardening constitutive model is presented to study the behavior of frozen soil under impact loading. In plasticity, a modified Drucker–Prager yield function is adopted. Based on the experimental investigations at different strain rates and different temperatures by means of split Hopkinson pressure bar, the Drucker–Prager criterion has been modified with consideration in the effect of strain rate, and the model parameters have been determined. Compared the constitutive model with the experimental results, the predicted tendencies of the model corresponded well to the test curves.
基金Project supported by the National Natural Science Foundation of China(No.11172251)the Open Fund of State Key Laboratory of Frozen Soil Engineering(No.SKLFSE201001)+1 种基金the Opening Project of State Key Laboratory of Explosion Science and Technology(Beijing Institute of Technology,No.KFJJ13-10M)the Project of Sichuan Provincial Youth Science and Technology Innovation Team,China(No.2013TD0004)
文摘By taking the frozen soil as a particle-reinforced composite material which consists of clay soil （i.e., the matrix） and ice particles, a micromechanical constitutive model is established to describe the dynamic compressive deformation of frozen soil. The proposed model is constructed by referring to the debonding damage theory of composite materials, and addresses the effects of strain rate and temperature on the dynamic compressive deformation of frozen soil. The proposed model is verified through comparison of the predictions with the corresponding dynamic experimental data of frozen soil obtained from the split Hopkinson pressure bar （SHPB） tests at different high strain rates and temperatures. It is shown that the predictions agree well with the experimental results.
基金This work was supported by the National Key Research and Development Program of China(2016YFB1200505)the National Natural Science Foundation of China(11672253)+1 种基金the Opening Foundation of State Key Laboratory for Strength and Vibration of Mechanical Structures(SV2019-KF-19)the Applied Basic Research Project of Science and Technology Department of Sichuan Province,China(2017JY0221).
文摘In this study,a series of experiments were carried out on the AZ31B magnesium alloy,including both a macro-experiment(mechanical experiment)and a micro-experiment(dislocation observation).Next,based on the consideration of the deformation mechanism of magnesium alloys(dislocation slip and twinning),a dynamic constitutive model of the magnesium alloy was established.In the developed model,the strain-rate-sensitivity control and the effect of temperature on the dynamic mechanical performance of the alloy were also investigated.The model parameters were determined by fitting the macroscopic experimental results.Next,the evolution of the micro-deformation mechanism was calculated by the developed model,and the trend of macro-mechanical behavior was also discussed.
