翻管数值参数分析法研究

采用塑性流动理论，薄壳无力矩理论及幂函数强化模型，对求解轴对称塑性平面应力问题的数值参数法作了进一步的研究，推导出成形力学分析的一阶微分方程组，在此基础上，将该微分方程相应用于薄壁圆管轴压外翻成形的稳态流动分析，计算时采用了四阶龙格库塔法，并获得了应力，应数值解，本文通过大量的计算，分析了边界条件对计算结果的影响，并将理论计算结果与实验作了比较。研究结果表明，轴对称塑性平面应力问题可以转换为一阶常

Research on Numerical Parameter Method and Its Application to Tube Inversion Process

A further study of the numerical method to deal with plane-plastic-stress problems with axial symmetry is made on the ground of plastic flow theory and strain-hardening model of the power function. A set of first-order ordinary differential equations are derived which are suitable for the problems. As an example of application,the equations,together with the so-called Runge-Kutta method,are used to get the numerical solutions of steady flow process in turning the inside-out of a thin circular tube under axial loading.The numerical computation is successful. Stresses and strains are obtained,and the effects of boundary conditions on the process are analyzed. The theoretical results of inversion loads are compared with the results of experiments. The optimum theoretical result of die radius in which the inversion load is minimum is in good accordance with the experimental one.