A COMPUTATIONAL FRAMEWORK FOR PREDICTING ONSET AND CRACK PROPAGATION IN COMPOSITE STRUCTURES VIA EXTENDED FINITE ELEMENT METHOD (XFEM)

Abstract

THE METHOD OF EXTENDED FINITE ELEMENTS (XFEM) HAS BEEN RELIABLY USED FOR ANALYZING COMPLEX STRUCTURES WITH GEOMETRIC NONLINEARITIES DUE TO ITS INTRINSIC CAPABILITY OF DISCONNECTING MESH FROM GEOMETRY. NEVERTHELESS, EVENTHOUG MANY RESEARCHERS HAVE WORKED IN THIS FIELD, IT IS RARELY FOUND IN LITERATURE 3D XFEM MODELS APPLIED TO NON-STANDARD COMPOSITE PARTS, SUCH AS TAPERED STRUCTURES OR JOINTS. IN THE PRESENT WORK, A FRAMEWORK FOR EVALUATING STRUCTURAL BEHAVIOR OF COMPOSITE STRUCTURES BY USING EXTENDED FINITE ELEMENT METHOD HAS BEEN DEVEL-OPED AND IMPLEMENTED. A NEW CRITERION FOR INITIATION AND CRACK PROPA-GATING DIRECTION DEFINITION BASED ON PUCK’S THEORY IS PRESENTED IN DE-TAILS. THE PROPOSED THREE-DIMENSIONAL MODEL FOR COMPOSITES BASED ON EXTENDED FINITE METHOD IS IMPLEMENTED THROUGH ABAQUS’ SUBROUTINES, USING OPTIMIZATION ALGORITHMS FOR COMPUTATIONAL EFFICIENCY. TO VERIFY THE PERFORMANCE OF THE MODEL TO DIFFERENT STACKING SEQUENCES AND GEOMETRY, A SENSIBILITY STUDY FOR THE MOST IMPORTANT PARAMETERS OF THE MODEL IS ALSO PROVIDED. FINALLY, EXPERIMENTAL RESULTS FROM THE LITERA-TURE ARE SHOWN AND USED TO VERIFY THE EFFICIENCY OF THE PROPOSED AP-PROACH