Isogeometric micromechanical damage analysis of fiber- reinforced composites by presenting a single- patch framework

Implementing isogeometric methodology in micromechanical analysis of composite materials has been recently investigated in some research studies. These research studies are based on multi-patch modeling which requires coupling constraints among the NURBS patches, and the domain decomposition effort in model preparation stage. This approach has been employed for small representative volume elements (RVE). However, small RVE neglects some characteristics of microstructure and larger one increases the number of required NURBS patches in multi-patch framework. As a step forward, this research presents a framework which simulates the RVE using a single NURBS patch. the presented framework has been used to include the effects of fiber distribution and porosities in simulated RVEs. In this regard, heterogeneity and 2D/3D voids within RVE are modeled only by inserting knots and modifying the control points. In addition to beneficial advantages of isogeometric methodology for RVE-based models, this framework simplifies isogeometric modeling of more complicated RVEs by eliminating the domain decomposition stage and avoiding coupling constraints between non-matching patches. The performance of the presented model has been verified by performing micromechanical damage analysis on several generated RVEs of unidirectional fiber-reinforced composites, in which matrix and fiber/matrix interfaces experience damage. The predicted damage evolutions under different loading conditions are in excellent agreement with prior experimental and numerical studies that demonstrate the veracity of the presented model.