On the Development of Horizontal Impact Test System (HITS): Estimation of Impact Loads and Deceleration

Abstract

A Horizontal Impact Test System (HITS) will be developed to characterize several energy absorption mechanisms, i.e. axial splitting, tube inversion, deformation/expansion, axial folding, and flattening. There were two alternatives that has been developed for launching mechanism, i.e. spring and Hopkinson pressure bar technique which will be chose further. The HITS mainly consists of a striker bar (impactor), a specimen as in a direct split-Hopkinson pressure bar technique and a die. This paper examines the possibility of using the 70 – 100 mm diameter of the striker bar to be implemented as the impactor for the developed HITS. Afterwards, the size of the striker bar will be a base of determining the launching mechanism. This study was conducted by numerical simulation using LS-DYNA® as the solver. Mild steel was used as a material of specimen. The Cowper-Symonds was used as the constitutive material model for the material of specimen, while the elastic material model was used for the striker bar and the rigid material model was used for the die. Six mechanisms with total of 96 cases of appropriate dimensions were studied. The main purpose of the simulation was to select the range of load cell and accelerometer which would be implemented in the real experimental setup. Based on the result of simulation, the range of load cell was 48 kN to 238 kN, while the range of accelerometer was 358 to 1250 g. Later on, the load vs. displacement can be used for predicting energy absorption for each mechanism.