Analysis of the impact of a thin-walled energy absorber column with symmetrical octagonal cross-section on a rigid body

Abstract

The superior energy absorption properties that energy absorber columns possess are significantly influenced by their mechanical properties and unique geometries. The symmetrical octagonal cross-section energy absorption columns are widely used in various engineering industries, including mechanical, civil, automotive, and other sectors, to absorb forces and prevent damage. This study uses finite element analysis to examine the crashworthiness of a thin-walled energy-absorbing column with a straight octagonal cross section, focusing on maximizing its specific energy absorption by varying the side length and wall thickness under dynamic impact while constraining the peak crushing force. In this study, the specific energy absorption (SEA) of the absorber is treated as the primary objective. The key design variables are the side length (a = 44 mm) and wall thickness (t = 1.6 mm) of the octagonal cross section, and the peak crushing force acts as a constraint. The thin walled column has an overall length of 300 mm and is fabricated from mild steel with density 7,830 kg m⁻³, Young’s modulus 207 GPa and yield stress 200 MPa. To investigate the specific energy absorption, a finite element analysis was conducted using the explicit solver in ABAQUS software. After geometric modeling, and analysis of the considered model and comparison with previous research, the specific energy absorption was determined, and the modeling error was about 8.2 percent. This model exhibits a remarkable ability to absorb the energy of the applied forces and has demonstrated excellent behavior and exceptional results compared to its counterparts.