Comparison of Various Criteria Determining the Direction of Crack Propagation Using the UDMGINI User Procedure Implemented in Abaqus

Abstract

This paper describes a method of predicting the direction of crack propagation implemented by user subroutines in the Simulia-Abaqus FEA system with the use of the extended finite element method (X-FEM). This method is based on displacements and stresses according to Westergaard’s solution of Griffith’s crack problem. During the calculations, in each crack increment, the algorithm reads the stresses and displacements in the model around the crack tip, calculates the criterion values at the read points, reduces them to a unit distance from the crack tip, fits a polynomial to these points, and finds the minimum of the function closest to the last propagation angle. The algorithm also decides when the crack grows, depending on a chosen criterion. Four criteria have been implemented to predict the direction of failure propagation: the maximum principal stress criterion, the Ottosen–Podgórski criterion, the new criterion described here based on the minimum component values of the displacement vector, and the maximum circumferential tensile stress (MTS). These criteria were verified in two tests: the three-point bending test of the notched beam and the anchor pull-out test. For these tests, the criterion built into Simulia Abaqus does not correctly define the crack path, which causes the crack propagation direction to “rotate” when simulating the fracture. The criteria developed here, in most cases, determine the crack path and the maximum force very well compared to real laboratory tests.

Influence of the Undercut Anchor Head Angle on the Propagation of the Failure Zone of the Rock Medium—Part II

“…A linear model of the rock medium was assumed in the numerical analysis. This was due to the fact that the algorithm for determining the direction of crack propagation, which is implemented in the ABAQUS program, in the case of the occurrence of I and II failure models, does not cope with solving this type of problem very correctly, e.g., [ 45 ]. As a result, the analysis of crack propagation can be carried out responsibly only in the range prior to the failure of the continuity of the rock medium.…”

Study on the influence of shot peening strengthening before shot peen forming on 2024-T351 aluminum alloy fatigue crack growth rate

“…In ABAQUS, the crack state can be described by PHILSM (Initial Crack Orientation) and PSILSM (Specify Crack Plane Position) 46 , 47 . The crack length output is not directly provided, so this paper develops a plug-in for the variation of crack length with cycle.…”

The Computational Method of Predicting the Crack Path in Confrontation with Laboratory Tests

“…So far, the authors of the paper have checked the effectiveness of the described method in the three-point bending test of a notched beam and the pull-out test of a self-undercutting anchor [6], a four-point bending test of a notched beam [4] and the simulation of the Griffith's crack [5]. The main goal of this paper is to check how the developed method deals with the determination of the crack path in the task presented below.…”

“…The operation of these subroutines will not be described in detail in this paper. More about them can be read in the author's previous publications [4,6].…”