Numerical Assessment of a Modified Hypoplastic Model with Enhanced Stability in Finite Element Simulations

Abstract

This study presents a comprehensive numerical investigation of a modified stress integration scheme applied to a simple hypoplastic constitutive model originally proposed by Wu Wei (1992). The modification aims to improve numerical stability, enhance convergence behavior, and eliminate spurious inhomogeneous deformation that frequently occurs in finite element simulations using conventional hypoplastic formulations. A fully implicit stress update algorithm incorporating a stability-controlled interpolation parameter is developed and implemented within the finite element framework. The proposed approach is evaluated through a series of numerical simulations, including oedometer compression, plane strain compression, and footing penetration tests conducted using Abaqus software. The simulation results indicate that the modified algorithm significantly improves computational robustness by reducing numerical oscillations and suppressing artificial shear stress evolution during loading. Furthermore, the method ensures homogeneous deformation at the element level, resulting in more reliable and physically consistent predictions. A comparative assessment with the elastoplastic Drucker–Prager model demonstrates that the modified hypoplastic formulation provides a more realistic representation of stress evolution, volumetric behavior, and dilatancy characteristics in granular materials. Overall, the proposed framework offers a stable, efficient, and accurate approach for finite element modeling of hypoplastic materials and has strong potential for application in advanced geotechnical engineering analyses.