Crashworthiness and Deformation Mechanism of a Guide-Wheel-Constrained Plate-Flow Energy Absorber Under Quasi-Static and Impact Loading: Experiments, Simulations and Theory

To meet the requirements for a long buffering stroke and a stable load response within a limited installation space, this study investigates a guide-wheel-constrained plate-flow energy absorber (GPEA) that dissipates impact energy through repeated bending–straightening deformation of a steel plate. Quasi-static compression and drop-hammer impact tests were conducted. Under the investigated loading conditions, the experimental results showed that the No. 20 carbon-steel plate underwent stable and continuous bending–straightening deformation under the constraint of the guide wheels without fracture. After entering the stable deformation stage, the quasi-static load remained at approximately 9.3 kN, while the plateau force under impact loading was about 10 kN, with an effective crushing stroke of 145.5 mm. On this basis, a finite element model was established, and the predicted deformation mode and stable load response showed good agreement with the experimental results. Furthermore, an elastic–plastic bending model incorporating linear material hardening was developed to quantitatively describe the through-thickness stress–strain evolution, energy absorption, and mean force of the steel plate. For idealized frictionless single-cycle cases with plate thicknesses of 2 mm and 5 mm, the differences between the theoretical predictions and numerical results were 3.6% and 4.3%, respectively. The proposed theoretical model, derived from the elastic–plastic bending and straightening process, reveals the underlying mechanism of plastic deformation accumulation and continuous energy dissipation during repeated changes in plate curvature.