An Adaptive-Based Finite Element Limit Analysis Approach for Geo-mechanics Problems

Abstract

Finite element-based upper bound and lower bound limit analysis are found to be an excellent tool for solving various stability structural problems with less computational cost. The accuracy and efficiency of the obtained solution is highly dependent on the intensity of elements in the high stress or stain gradient region. Therefore, an adaptive meshing procedure is required to reduce the gap between upper and lower bound solutions. The adaptive meshing procedure presented in this paper is based on two basic concepts (a) a posterior error indicator and (b) an unstructured mesh generator. The posterior error estimator is based on intensity of maximum shear strain rate (γmax) has been used. Open-source software TRIANGLE and TETGEN have been used to generate unstructured meshes for 2D and 3D problems, respectively. A plane strain and a 3D foundation problem have been analyzed and steps involve in calculation have been clearly mentioned in the paper. The present analysis method is found to be efficient and accurate.