Damage Control Measures in Composites: BVID Damage Progression

Abstract

Abstract Damage control in composites is becoming one of the major topics of research as primary structures are transitioning to composites for the benefits of their lightweight, ease of manufacturability, and high strength-to-weight ratio. However, one of the significant challenges with composites is that there is still no accepted standard to define the damage and its propagation compared to well-studied metallic structures. This ongoing research follows the guidelines of national Agencies with the initiative to create an efficient simulation-based approach to predict the potential initiation of damage propagation in a composite structure. The predictive analysis will incorporate the Onset Theory, a physics-based methodology for assessing the Onset of irreversible deformation. The method utilizes the critical dilatation and distortion of the constituent materials of the composite material system following the micromechanical de-homogenization of the deformed composite material system. As a result, there is a limited dependency on parameters extracted from representative experiments. The approach consists of extracting the critical dilatation and distortion values for each constituent material from tested coupons, developing a sequence of low-velocity impacts (LVI) to generate Barely Visible Impact Damage (BVID), establishing the catastrophic load environments for the impaired coupons subject to in-plane uniaxial compression while monitoring the propagation of the damage. Then, numerically simulate the initiation of damage propagation using the critical dilatation and distortion of the constituent materials, and finally, compare the numerically derived critical in-plane compression loads to the critical values obtained from the sample’s Compression After Impact (CAI) testing.