CRACK ANALYSIS IN ORTHOTROPIC MEDIA USING COMBINATION OF ISOGEOMETRIC ANALYSIS AND EXTENDED FINITE ELEMENT

The main contribution of this paper is to propose an IGA formulation to model stationary cracks within orthotropic media by combination of XFEM enrichment functions and level set functions. For modeling cracks in solution field crack face and crack tips are considered separately and the control points that are related to each part are enriched with different approaches. The control points related with the crack face are enriched using the Heaviside enrichment functions. Level set functions are used to distinguish the control points correspond to crack tips and crack face. Stress intensity factors are employed to compare the results of XIGA with other methods. Several numerical examples considering crack inclination angle and material orientation axis are solved to verify the XIGA formulation. The results fairly conform to available methods, however less DOFs are used in XIGA.