Crushing of carbon-fiber reinforced thermoplastic energy absorbers under axial impact: Numerical modeling and experimental tests

This study presents a numerical and experimental investigation aimed at assessing the impact behavior, energy absorption characteristics, and failure modes of thermoplastic composite energy absorbers subjected to axial impact loads. The energy absorbers consist of thin-walled cylinders manufactured from woven polyphenylene sulfide carbon composite. Finite element analyses are conducted to predict the structural response of the tubes. To validate the numerical predictions, two specimens are manufactured and subjected to impact tests. The results demonstrate good agreement between the simulated models and the experimental tests. The experimental results reveal a progressive failure mode characterized by brittle fracture and delamination of the composite fabric. Specific energy absorption values of up to 45 kJ/kg are achieved by the thermoplastic composite energy absorbers, indicative of their satisfactory crashworthiness performance under impact loading conditions. In addition, the results are compared with four quasi-static tests conducted in a previous study to investigate the influence of strain rate. Compared to quasi-static conditions, the composite tubes tested under dynamic conditions exhibit an average force about 60% lower. This suggests that the energy absorption capabilities of the material are dependent on the strain rate.