闭口薄壁截面直杆的塑性解

基于Mises屈服条件和增量理论，在理想弹塑性模型框架下，通过无量纲计算，求解闭口薄壁截面直杆在压、扭组合变形下应力分量解析解.对受压（拉）、扭组合变形的闭口薄壁截面直杆，在其材料屈服进入塑性阶段后，施加不同的变形路径，理论求解导出闭口薄壁截面直杆受压和扭转联合作用对应的2个对偶常微分方程，求解方程得到各应力分量的解析值；为进一步研究闭、开口薄壁截面直杆的屈曲奠定了基础.

Plastic Solution of Thin-Walled Straight Bar with Close Section

Based on Mises yielding condition theory,incremental theory and the assumption that the material is ideal elastoplastic,this paper obtained stress components of thin-walled straight bar with close section under tension,compression and torsion combined deformation by using non-dimensional method.When thin-walled straight bar with close section is subjected to tension,compression and torsion combined deformation,and that the materials get to the plasticity stage,two correlative ordinary differential equations in respect with the compression and torsion subjected on the thin-walled straight bar with close section are obtained based on the theoretical analysis.Stress components can be obtained with analytical solution by solving the ordinary differential equation.Those will lay the foundation for the studies on buckling and stability of thin-walled straight bar with close and open section.