轨道车辆碰撞吸能闭孔泡沫铝优选设计

Optimum Selection and Design Methodology for Closed-cell Aluminum Foam Used in Railway Vehicle's Crashworthy Energy Absorption Component

基于不同应变率加载条件下不同密度闭孔泡沫铝能量吸收曲线,进行轨道车辆碰撞吸能用泡沫铝材料优选设计,实现了泡沫铝的高效选择。提出轨道车辆碰撞吸能用泡沫铝逆向设计流程与优选方法,通过初选碰撞场景,确定泡沫铝专用吸能元件设计总体需求,构建其标准化应力与单位体积标准化吸能量之间的映射关系,预选厚度,正向计算碰撞条件下的应变率及对应的能量吸收能力,并进行需求比对,循环迭代,直至收敛于最优密度及厚度。最后,通过动车组头车耐撞性吸能元件设计实例,验证了泡沫铝密度与厚度优选的高效性,所提方法可大大提高轨道车辆碰撞吸能用泡沫铝的选材效率。

An extensive optimum selection and design for closed-cell aluminum foam used in railway vehicle was performed based on the comprehensive energy absorption curves. These curves were obtained from kinds of foams with different density ratios loading at different strain-rates. Afterwards, an effective optimum selection as well as design was conducted. A reverse design process and optimum selection methodology was put forward by assuming the train collision scenario, determining the overall energy-absorbing requirement, constructing the mapping relationship between standardized stress and standardized energy absorption per unit volume, proceeding positive-going calculation of the energy-absorbing capacity at corresponding situation, and comparing, iterating circularly, until it converged to the optimal density ratio and optimal thickness. Finally, an optimization design example was given with crashworthy EMU head vehicle＇s energy-absorbing component, and corresponding optimal density and thickness was obtained. This methodology turned out to be an effective and useful tool to aid in selecting the most appropriate aluminum foam.