Abstract
This paper presents a novel three-dimensional adaptive kinematic yield design framework based on the bubble-enriched face-based smoothed finite element method (bFS-FEM). The enrichment of face-based smoothing with bubble functions enhances approximation capability and effectively eliminates volumetric locking, a common limitation of conventional low-order FEM in incompressible materials. To further improve accuracy without compromising efficiency, an adaptive mesh refinement strategy is incorporated into the formulation. In addition, a plastic dissipation error estimator based on the three-dimensional displacement fields of bFS-FEM is developed to guide the refinement process. The resulting discretization leads to a second-order cone programming (SOCP) problem, which ensures numerical robustness and scalability to large-scale analyses. Numerical benchmarks demonstrate that the proposed method delivers locking-free, accurate, and physically consistent solutions, highlighting its potential as an efficient and reliable tool for collapse analysis of complex three-dimensional structures.