Failure mechanism of 3D structures cannot always be produced by the low-order finite elements due to the so-called volumetric locking effect. In this paper, dual numerical approaches based on the bubble face-based smoothed finite element method (bFS-FEM) are developed, ensuring that the locking problem is prevented and accurate load factors of elastic-perfectly plastic structures under cyclic actions are achieved. The failure mechanisms, in terms of plastic dissipation, are realized as incremental or alternative plastic failure modes, enabling different treatments in engineering practices. Moreover, the pseudo-static approach is capable of providing three-dimensional stress fields at the failure state, which is crucial for structural design. Interaction diagrams associated with various load-types and-ranges are illustrated in numerical experiments, showing that the bearing capacity envelopes of structures under cyclic loads are evidently smaller than that of proportional loads.

中文翻译：

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使用基于 bFS-FEM 的数值方法对 3D 结构进行循环载荷下的双重失效分析


由于所谓的体积锁定效应，3D 结构的失效机制并不总是由低阶有限元产生。本文开发了基于气泡面的平滑有限元方法 （bFS-FEM），确保了防止锁定问题，并实现了在循环作用下弹性完美塑性结构的精确载荷因子。就塑性耗散而言，失效机制被实现为增量或替代塑性失效模式，从而在工程实践中实现不同的处理。此外，伪静力方法能够在失效状态下提供三维应力场，这对于结构设计至关重要。数值实验说明了与各种载荷类型和范围相关的相互作用图，表明结构在循环载荷下的承载力包络线明显小于比例载荷的承载力包络线。