Adaptive Hierarchical Kinematics in Modeling Progressive Damage and Global Failure in Fiber-reinforced Composite Laminates

Abstract

This article investigates the feasibility of utilizing adaptive kinematics to reduce the computational effort of finite element modeling of progressive damage and global failure in fiber-reinforced composite laminates. In the present context, adaptive kinematics refers to the selective use of different types of macroscopic laminate models for different regions of the computational domain, based on the solution complexity within each region. Each of these macroscopic laminate models can be distinguished by the manner in which the displacement field is assumed to vary through the thickness of the laminate. In the present study, kinematic adaptivity is made possible through the use of variable kinematic finite elements (VKFE) that are developed by hierarchically combining two or more types of assumed displacement fields in a single finite element domain. The hierarchical data structure of the VKFE greatly simplifies the process of connecting elements that represent different types of laminate theories, thus facilitating adaptive analysis. The adaptive kinematic concept is demonstrated for the bending of simply supported laminates that exhibit diffuse, widespread damage and laminate tensile test specimens that exhibit very intense localized damage due to the free edge effect. The results obtained in this study clearly demonstrate that the use of adaptive kinematics can significantly reduce the overall computational effort of progressive damage solutions without compromising solution accuracy.