中文摘要：

该文引入非线性互补方法来求解边界元法的弹塑性问题，其中方程组由内部点应力方程和反映塑性本构定律的互补函数形成。涉及的域积分采用径向积分法转化为边界积分。通过受内压的厚壁圆筒的应力、位移和荷载．位移情况表明了该算法的精度。

英文摘要：

A nonlinear complementarity approach is presented to solve elastoplastic problems by boundary element method, in which the equations are formulated by stress equations of intemal points and complementarity function obtained from plasticity constitutive law. The domain integrals involved are transformed into boundary integrals by radial integration method. The algorithm＇s precision is demonstrated by stress, displacement and load-displacement results of a thick-walled cylinder subjected to internal pressure.