The paper proposes a novel automatic adaptive recovery stress edge-smoothed finite element method (ES-FEM) that determines the maximum load capacity of inelastic structures at plastic collapse. This approach performs solely a series of elastic ES-FEM analyses with systematic modulus variations (considering the influences of stress singularity) to converge the collapse load solutions. The smoothed $C^0$-continuous recovery stress field ensures the satisfaction of static admissible stress and yield conformity conditions underpinning lower-bound limit analysis theorems. A modified modulus error function within the newest node bisection algorithm enables automatic mesh refining and coarsening constructions, and fast convergence to the lower-bound collapse limit.

本文提出了一种新的自动自适应恢复应力边缘平滑有限元方法（ES-FEM），该方法确定了非弹性结构在塑性倒塌时的最大承载能力。该方法仅执行一系列弹性 ES-FEM 分析，系统模量变化（考虑应力奇异性的影响）以收敛坍塌载荷解决方案。平滑的$C^0$- 连续恢复应力场确保满足支持下限分析定理的静态许用应力和屈服一致性条件。最新节点二等分算法中修改的模量误差函数可实现自动网格细化和粗化构造，并快速收敛到下限崩溃极限。