A new composite structure impact performance assessment program

Abstract While previous researchers have conducted their study on the relative impact performance of composite structures from a force or an energy standpoint only, this proposed Composite Structure Impact Performance Assessment Program (CSIPAP) suggests a multi-parameter methodology to gain further insight in the impact behavior of composite structures. These are peak and critical force; critical and dissipated energy; contact duration and coefficient of restitution (COR), which is direct indication of effective structural stiffness; and residual stiffness (normalized contact duration) which yields a plot that bears a striking resemblance with the normalized Compression After Impact (CAI) strength. Using a determinate impactor/target system as baseline configuration, the program is applied toward the understanding of the role played in an impact event by fundamental impactor and target parameters. The equations previously derived for the prediction of the force–energy and residual stiffness curves are shown to apply to the configurations tested, thus confirming their general validity. A modification to the existing effective structural stiffness formulation, which does not account for impactor characteristics, is proposed, and it comprises the impactor material, size and mass characteristics.