Compared with the traditional rigid plastic/rigid viscoplastic(RP/RVP) FEM(based on iteration solution),RP/RVP FEM based on linear programming (LP) has some remarkable advantages,such as it's free of convergence...Compared with the traditional rigid plastic/rigid viscoplastic(RP/RVP) FEM(based on iteration solution),RP/RVP FEM based on linear programming (LP) has some remarkable advantages,such as it's free of convergence problem and its convenience in contact,rigid zone,and friction force treatment.The numerical model of RP/RVP FEM based on LP for axisymmetrical metal forming simulation is studied,and some related key factors and its treatment methods in formulation of constraint condition are proposed.Some solution examples are provided to validate its accuracy and efficiency.展开更多
By using the energy criterion in [3], the impact torsional buckling for the rigid plastic cylindrical shell is studied. The linear dynamic torsional buckling equations for the rigid plastic shell is drived, and the cr...By using the energy criterion in [3], the impact torsional buckling for the rigid plastic cylindrical shell is studied. The linear dynamic torsional buckling equations for the rigid plastic shell is drived, and the critical impact velocity is given.展开更多
Based on synthetically considering the coupled thermo mechanical relations between temperature and deforming, a numerical simulation of the forging process for the special long cone shaped workpiece of Al 5.44Mg 2...Based on synthetically considering the coupled thermo mechanical relations between temperature and deforming, a numerical simulation of the forging process for the special long cone shaped workpiece of Al 5.44Mg 2.15Li 0.12Zr alloy at high temperature was conducted by using the rigid visco plastic finite element method. The relations between the total load and the displacement during the forging, and the distributions of stress, strain, temperature and strain rate, which can provide useful information for the process design, are obtained.展开更多
The classical problem of a round metal tube collapsing in concertina mode when subjected to axial compressive loading has been reexamined both theoretically and experimentally. The model including an eccentricity fa...The classical problem of a round metal tube collapsing in concertina mode when subjected to axial compressive loading has been reexamined both theoretically and experimentally. The model including an eccentricity factor proposed by Wierzbicki et al. and modified by Singace et al. has been taken one step further to obtain the real load-displacement history and to investigate eccentricity effects. The influence of the eccentricity parameter m on the mean crushing load was discussed according to the present analysis. Experiments were carried out to verify the eccentricity effects. The results show that experimental and theo- retical load-displacement curves match perfectly, especially in terms of half wavelength. Unlike previous re- searchs, the results suggest that m is not a fixed value and may affect energy absorption.展开更多
文摘Compared with the traditional rigid plastic/rigid viscoplastic(RP/RVP) FEM(based on iteration solution),RP/RVP FEM based on linear programming (LP) has some remarkable advantages,such as it's free of convergence problem and its convenience in contact,rigid zone,and friction force treatment.The numerical model of RP/RVP FEM based on LP for axisymmetrical metal forming simulation is studied,and some related key factors and its treatment methods in formulation of constraint condition are proposed.Some solution examples are provided to validate its accuracy and efficiency.
基金Project supported by the National Natural Science Foundation of China
文摘By using the energy criterion in [3], the impact torsional buckling for the rigid plastic cylindrical shell is studied. The linear dynamic torsional buckling equations for the rigid plastic shell is drived, and the critical impact velocity is given.
文摘Based on synthetically considering the coupled thermo mechanical relations between temperature and deforming, a numerical simulation of the forging process for the special long cone shaped workpiece of Al 5.44Mg 2.15Li 0.12Zr alloy at high temperature was conducted by using the rigid visco plastic finite element method. The relations between the total load and the displacement during the forging, and the distributions of stress, strain, temperature and strain rate, which can provide useful information for the process design, are obtained.
基金Supportedby the National Postdoctoral Science Foundation (No.2002-17) and the National Natural Science Foundation of China(No. 50275077)
文摘The classical problem of a round metal tube collapsing in concertina mode when subjected to axial compressive loading has been reexamined both theoretically and experimentally. The model including an eccentricity factor proposed by Wierzbicki et al. and modified by Singace et al. has been taken one step further to obtain the real load-displacement history and to investigate eccentricity effects. The influence of the eccentricity parameter m on the mean crushing load was discussed according to the present analysis. Experiments were carried out to verify the eccentricity effects. The results show that experimental and theo- retical load-displacement curves match perfectly, especially in terms of half wavelength. Unlike previous re- searchs, the results suggest that m is not a fixed value and may affect energy absorption.
