Elasto-plastic cell-based smoothed finite element method solving geotechnical problems

Abstract

This work develops an elasto-plastic cell-based smoothed finite element method (CSFEM) for geotechnical analysis. The formulation incorporates a smoothed strain field into the standard elasto-plastic framework based on the Mohr-Coulomb criterion and is implemented in ABAQUS through a user-defined element (UEL). A UEL-UMAT data-transfer strategy is introduced to enable post-processing of stress and strain in ABAQUS. The method is assessed using several benchmark problems, including three classical examples, a tunnel excavation, and a slope stability analysis. The results show that the CSFEM achieves accuracy comparable to or slightly better than the conventional FEM and matches analytical or reference solutions for the examined cases. These findings indicate that the proposed CSFEM provides a practical and robust alternative for routine elasto-plastic analyses in geotechnical engineering.

Figures (20)

• Figure 1: Construction of a cell-based smoothing domain.
• Figure 2: Framework of implementing the elasto-plastic CSFEM in ABAQUS using UEL and UMAT subroutines.
• Figure 3: Data-linking scheme for transferring stress, strain, and other state variables from the UEL to UMAT-based visualization elements in ABAQUS.
• Figure 4: Quarter model of a thick-walled cylinder subjected to internal pressure at the inner surface.
• Figure 5: Four levels of mesh refinement; (a) 0.125 m mesh size; (b) 0.0625 m mesh size; (c) 0.03 m mesh size; (d) 0.015 m mesh size.