Modeling of Crashworthiness Criteria based on Variation of Hole as Crush Initiator in Thin-Walled Square

Abstract

Crashworthiness is the ability to protect its occupant by absorbing the energy of impact during a collision. A crush initiator is one way to increase crashworthiness criteria at collision. The most widely applied crush initiator applications are holes, wall thickness reduction, grooves, notch, bead and corrugated. This study discussed making a functional model from the crashworthiness criteria which is known by CFE and SEA. Variable used variations of the crush initiator in the form of circular holes with different rotation angles and diameters. The rotation angle referred to in this study was 2 holes which are rotated based on the midpoint of the hole distance to the radial axis of the hole. The crush initiator was placed in a square column at each side with steel material. Besides, the wall thickness variable was added which can increase the energy absorption during a collision. The method used numerical simulation and experimental dynamic loading. The numerical simulation used the explicit finite element method by using ESI PAM-Crash. Both methods used the drop test model by using impact transferability. Impact transferability was rigid which was used to transfer impact loading during impact conditions. Experimental was used to validate the function model which was obtained through the least square method with sampling from numerical simulations. The results showed the same patterns produced by the functional and experimental models using the Taguchi method (L9) with 3 runs. The maximum of this pattern is 23% for CFE and 17% for SEA. Meanwhile, the average error of the S/N ratio shows 8.77% for CFE and 2.16% for SEA. This model function could be used by a crashworthy designer to estimate the value of CFE and SEA.