3차원 형상의 금속 구조체를 가진 초경량 금속 샌드위치 판넬의 충격 특성 분석

Abstract

Recently, the development of an inner structured and bonded panel (ISB panel) with metallic pyramidal inner structures has been actively undertaken to improve the safety and the energy efficiency of the transport vehicles. In order to apply the ISB panel to transport vehicles, impact characteristics of the ISB panel should be evaluated quantitatively. The objective of this paper is to investigate into impact characteristics of the ISB panel through impact tests and three dimensional finite element analysis. In order to empirically evaluate impact properties and energy absorption characteristics of the ISB panel, several drop impact tests have been performed. The impact tests have been performed for the case of the fixed boundary condition, so called a stretching boundary condition, and a free boundary condition, so called a drawing boundary condition. The empirical parameters have been chosen as diameter of impact head, impact energy and joining types between skin sheets and inner structures. From the results of the impact tests, force-deflection characteristics, absorption characteristics of the impact energy, deformation characteristics and the failure characteristics of the ISB panel have been quantitatively evaluated. Through the comparison of the results of the impact test of ISB panel and those of the stainless sheet with an equivalent weight for the ISB panel, it has been shown that the ISB panel has superior absorption characteristics of the impact energy to the stainless sheet. In order to investigate the absorption mechanism of the impact energy, deformation characteristics and characteristics of stress-strain distribution of the ISB panel, the three dimensional finite element analysis has been carried out using a commercial code ABAQUS. Explicit time integration method has been utilized to analysis the impact tests for cases of free and fixed boundary conditions. Through the comparison of the results of the impact tests and those of the analyses, a proper FE model has been obtained. From the results of the FE analyses, the deformation pattern of the ISB panel and the inner structures, the energy absorption mechanism of the ISB panel and the variation of the stress and strain distribution in the ISB panel have been quantitatively evaluated when the impact energy is applied to the ISB panel.