摘要
倾斜荷载在汽车碰撞事故中无法避免,严重影响多胞材料的力学响应。以内凹三角形负泊松比材料为研究对象,通过显式动力有限元软件LS-DYNA具体分析了冲击倾角(0°~10°)与冲击速度(20~70 m/s)对内凹三角形负泊松比材料面内冲击的变形模态和动力响应的影响,并构造了完整的变形模式分类图。引入最佳承载角的概念,当冲击倾角β=4°时,诱发了稳定有序的变形模式,使得抵抗变形的形式主要以结构胞壁的压缩与弯曲为主,平台应力值与吸能值得到了较大的提升,进一步发挥了结构的抗承载能力,甚至超过了理想的轴向冲击工况。这一特征与六边形蜂窝结构有所不同,对汽车吸能构件的设计具有重要的指导意义。
Inclined loading conditions cannot be avoided in traffic accidents and strongly influence the mechanical response of cellular material.In present study,based on explicit dynamic finite element simulation by LS-DYNA,deformation modes as well as dynamic responses of a concave triangle with negative Poisson's ratio structure undergoing non-ideal oblique impact loadings have been investigated considering as significant parameters of the load angle(ranging from 0°to 10°)and the impact velocity(ranging from 20 m/s to 70 m/s),and corresponding mode classification map was constructed.Evident influence of asynchronous loading as well as impact speed on the deformation mode evolution has been determined.The concept of optimal bearing angle was introduced.When the load angle isβ=4°,a stable and orderly deformation mode was induced.The form of resisting deformation is mainly based on the compression and bending of the structural cell wall,so that the platform stress value and energy absorption value have been made a great improvement.The anti-bearing capacity of the structure has been further exerted,even exceeding the ideal axial impact condition.The present study provides a significant advancement to the comprehensive understanding of the dynamic response of cellular material,which could be used to develop more valuable guidelines for design purposes in automotive energy absorbing devices.
作者
马芳武
梁鸿宇
赵颖
陈实现
蒲永锋
MA Fangwu;LIANG Hongyu;ZHAO Ying;CHEN Shixian;PU Yongfeng(State Key Laboratory of Automotive Simulation and Control,Jilin University,Changchun 130025,China)
出处
《振动与冲击》
EI
CSCD
北大核心
2020年第4期81-87,共7页
Journal of Vibration and Shock
基金
国家重点研发计划资助项目(2016YFB0101601)
吉林省省校共建计划专项项目(SXGJQY2017-7
SXGJSF2017-2-1-5)
关键词
倾斜荷载
内凹三角形
负泊松比效应
平台应力
面内冲击
能量吸收
inclined load
concave triangle
negative Poisson’s ratio configuration
platform stress
in-plane impact
energy absorption
