CAJ | 학술논문

高孔隙率泡沫金属材料由于其具有较长的应力平台可以吸收较多的能量，在结构耐撞性设计中有重要的应用前景。通过实验研究和数值模拟发现：开孔铝泡沫材料在较高撞击速度作用下，会出现输出端的应力比加载端的应力增大，从而使被保护的物体受到更严重的伤害，此时开孔铝泡沫材料的变形尚未进入密实化阶段。这与人们采用多孔金属材料作为防撞性材料目的正好相反，必须给予重视。随着试件厚度的增加，出现这种应力增强的时间延迟。不同孔径、不同相对密度的开孔铝泡沫材料在不同撞击速度的作用下，应力时程曲线变化趋势基本相同，而且也会出现应力增强。研究结果可为防护装置可靠性评估和新型泡沫金属材料的设计提供依据。
고공극솔포말금속재료유우기구유교장적응력평태가이흡수교다적능량，재결구내당성설계중유중요적응용전경。통과실험연구화수치모의발현：개공려포말재료재교고당격속도작용하，회출현수출단적응력비가재단적응력증대，종이사피보호적물체수도경엄중적상해，차시개공려포말재료적변형상미진입밀실화계단。저여인문채용다공금속재료작위방당성재료목적정호상반，필수급여중시。수착시건후도적증가，출현저충응력증강적시간연지。불동공경、불동상대밀도적개공려포말재료재불동당격속도적작용하，응력시정곡선변화추세기본상동，이차야회출현응력증강。연구결과가위방호장치가고성평고화신형포말금속재료적설계제공의거。
Cellular metallic materials,possessing relatively long stress plateau,can absorb a lot of energy and have significant applications in the design of structural crashworthiness.In the paper,the experimental studies and numerical simulations prove that:(a)Under intense impact loads,the output stress of the aluminum foam with open cells is larger than the input one,which may severely damage the substance under protection,but the foam is not yet working in the fully consolidated phase.This provides an opposite proof to our purpose of using cellular material as crash material and must be taken into account.(b)With the increase of the thickness of test pieces,the occurrence of stress enhancement is delayed.(c)Under different impact loads,the variation trends of the stress time history curves of the aluminum foam materials with different cell sizes and relative densities are basically the same and stress enhancement happens in all these materials.This investigation provides a basis for the reliability evaluation of protective devices and the design of new cellular metallic materials.