Areas of Research

Potential-Based Cohesive Zone Model

In the cohesive zone model, the fundamental issue for simulation of failure mechanisms is the characterization of cohesive interactions along the fracture surface. A generalized potential-based constitutive model (PPR: Park-Paulino-Roesler) for mixed-mode cohesive fracture is developed in conjunction with physical parameters such as fracture energy, cohesive strength and shape of cohesive interactions. It characterizes different fracture energies in each fracture mode, and can be applied to various material failure behavior (e.g. quasi-brittle). The unified potential leads to both intrinsic (with initial slope indicators to control elastic behavior) and extrinsic cohesive zone models.

PPR model


Dynamic Cohesive Fracture




ABAQUS UEL for the PPR potential-based cohesive model

The PPR potential-based cohesive zone model is implemented in a commercial software, i.e. ABAQUS, as a user-defined element (UEL) subroutine. The source code of the UEL subroutine is provided for a two-dimensional linear cohesive element for educational purposes.

Integration of singular enrichment functions

A mapping method is developed to integrate weak singularities, which result from enrichment functions in the generalized/extended finite element method. The integration scheme is applicable to 2D and 3D problems including arbitrarily shaped triangles and tetrahedra. Implementation of the proposed scheme in existing codes is straightforward. Numerical examples for 2D and 3D problems demonstrate the accuracy and convergence properties of the technique.

© Kyoungsoo Park
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