Abstract

The numerical prediction of impact induced damage to composite materials and the subsequent residual strength under compression loading continues to be a challenging task. The current study proposes an innovative material model calibration procedure to approximate the optimal combination of material model parameters that represent the experimental response of Cycom 977-2 material.

The optimization algorithm is based on the comparison of the numerical force-strain or force-displacement curves with the corresponding experimental ones and includes the most common quasi-static material characterization tests. For minimizing the parameters combinations, the calibration process was divided into two stages. The first stage includes the in-plane characterization tests (Tension 0o & 90o, Compression 0o & 90o, Shear and Open-Hole Tension test) for calibration of orthotropic damage material model.

Whereas the second one consists of the mode I and mode II interlaminar fracture tests as well as the short beam shear test and targets to cohesive model calibration.

For validation of proposed methodology, low and high velocity impact tests at the energy level of 30 J were carried-out and simulated. Afterwards, the damaged specimens were tested to compression loading according to AITM 1-0010 standard.

The numerical contact force-time curve, the time history of projectile kinetic energy as well as the compression after impact maximum force are correlated with the experimentally derived results. Finally, proposals are provided for further enhancement of numerical results.