Novel strain energy based coupled elastoplastic damage and healing models for geomaterials-part II: Computational aspects

In Part I of this sequel (Ju, J.W., Yuan, K.Y. and Kuo, A.W. (2010). Novel Strain Energy Based Coupled Elastoplastic Damage and Healing Models for Geomaterials-Part I: Formulations, International Journal of Damage Mechanics, DOI: 10.1177/1056789511407359), we have developed innovative strain energy based coupled elastoplastic hybrid isotropic and anisotropic damage-healing formulations for geomaterials under complex 2D earth-moving processes. Emanating from a micromechanics-based brittle (tensile) damage characterization (P+) and a ductile (mixed tension-compression) damage-healing characterization (Pmix+), the proposed hybrid isotropic and anisotropic damage-healing models for soils are implemented. Entirely new computational algorithms are systematically developed based on the two-step operator splitting methodology. The elastic damage-healing predictor and the plastic corrector are consistently implemented within the existing Nonlinear Meshfree Analysis Program at University of California, Los Angeles (Chen, J.S., Wu, C.T., Yoon, S. and You, Y. (2001). A Stabilized Conforming Nodal Integration for Galerkin Meshfree Methods, International Journal for Numerical Methods in Engineering, 50: 435-466). Several numerical simulations featuring sophisticated earth excavation, transport, compaction, and a numerical notched soil bar under cyclic tension-compression loading are presented to illustrate the salient elastoplastic damage and healing features of soils, such as shear band and partial recovery of soil stiffness due to compression (compaction) by the proposed innovative damage-healing models and step-by-step computational algorithms.