Crushing behavior of GFRP composite-reinforced PVC tubes: Experimental testing and numerical simulation

This paper introduces glass fiber reinforced polymer (GFRP)-reinforced Polyvinyl Chloride (PVC) tubes, both corrugated and non-corrugated, designed as energy absorber devices. The PVC tubes were externally and internally reinforced with GFRP composite oriented at +/- 45 degrees and subjected to quasi-static axial compression tests. Results indicated that all reinforced tubes exhibited significantly higher load-bearing capacity, energy absorption (EA) capability, and crushing force efficiency (CFE) compared to standard PVC tubes. Among the tested specimens, externally reinforced corrugated tubes demonstrated the highest specific energy absorption (SEA), surpassing other configurations by 17.5 kJ/kg when considering both pre- and post-crushing stages combined. However, these corrugated specimens showed instability during crushing, reflected in poor instantaneous crush force efficiency (iCFE) and the lowest iCFE among the composite tubes, with an average decrease of 43.59%. The corrugation notably increased the initial peak load, enhancing energy absorption in the pre-crushing stage without compromising the stability of crush force efficiency. Additionally, the combination of external and internal reinforcement significantly improved CFE and iCFE. Consequently, the PVC tubes combining corrugation with both external and internal reinforcement emerged as the best-performing configuration among all tested tubes. Furthermore, a 3D Finite Element (FE) model was developed using ABAQUS FE code with user-defined subroutines to simulate the crushing process. The constitutive models and numerical procedures employed are detailed. The FE model's predictions showed a satisfactory correlation with experimental results, providing valuable insights into the crushing mechanics and offering a predictive tool for future design optimizations.