增量理论有限元是求解弹塑性问题的有效方法.对于每级荷载增量的取法,通常是将总荷载扣除弹性极限荷载后分成 n 级施加.本文介绍的山田法是在每级增量阶段内只让一个单元屈服,据此反推荷载增量,进而进行力学分析的方法.该法的最大特点是可利用电算来模拟加载试验过程.文中以平面问题为例介绍了山田法原理、计算步骤、程序框图及其算例. Incremental theory FEM is an effective method for solving elastoplastic problems. For each stage of load increment, the total load is usually divided into n stages after deducting the elastic limit load. The Yamada method introduced in this paper is at each stage of increment. Only one unit is yielded, and the incremental load is then reversed. Then the method of mechanical analysis is performed. The most important feature of this method is that it can be used to simulate the loading test process. In this paper, the principle of Yamada Law is introduced by taking the plane problem as an example. Calculation steps, block diagrams and their calculations.