摘要
采用Hypermesh 9.0和Lsdyna 971数值仿真分析了棱边强化对薄壁方管轴向压溃过程能量吸收机理的影响。基于单个方管折叠单元能量平衡方程,采用分项能量修正法和影响因子归一化建立了棱边强化薄壁方管轴向压溃能量平衡方程。理论推导出棱边强化方管平均压溃力预测公式和吸能增幅表达式,其中,平均压溃力的仿真结果与预测公式计算结果吻合较好。Q235方管压溃试验结果表明,棱边强化方管平均压溃力公式也可用于预测原始方管,且效果更好。吸能对比表明:棱边强化后,棱边与平板的塑性变形在轴向压溃过程中存在强耦合关系,两部分的吸能均有提升。对于截面为56.36mm×56.36mm、厚度为1.0mm的薄壁方管,棱边约强化4倍,4条棱边仅占薄壁方管截面9.09%,理论上可使方管总体吸能量提升近30%,可见棱边强化能显著提升薄壁方管轴向压溃吸能水平。
A numerical simulation is conducted with Hypermesh 9.0 and Lsdyna 971 to analyze the effects of ridgeline strengthening（RS） on the energy absorption mechanism of thin-walled square tube subjected to axial crushing.Based on the energy balance equation of a folding element in common square tube,the energy balance equations of RS thin-walled square tube in axial crushing are set up by using partial energy correction and influencing factor normalization.The predicting formulas for mean crushing force and the expression of energy absorption increasing margin of RS thin-walled square tube are derived theoretically,in which the results of simulation agree well with the results calculated by predicting formulas.Crushing test results of Q235 square tube show that the predicting formula of mean crushing force for RS thin-walled square tube is also suitable for original square tube with better prediction result.The comparison of energy absorbed indicates that there is a strong coupling relationship of plastic deformation between stress-strengthened ridgeline and plate in axial crushing,so the energy absorbed in both parts all increase.For a specific RS thin-walled square tube with a cross section of 56.36 mm×56.36 mm and a thickness of 1.0 mm,the yield stresses of its four ridge lines are strengthened to as high as 4 times of original ones,so its energy absorbed can increase by about 30% theoretically,though the proportion of four strengthened ridges is only 9.09% of the total perimeter of cross section,demonstrating that RS can significantly enhance the energy absorption capability of thin-walled square tube in axial crushing.
出处
《汽车工程》
EI
CSCD
北大核心
2017年第11期1252-1260,共9页
Automotive Engineering
基金
国家863计划项目(2012AA111302)资助
关键词
薄壁方管
棱边强化
能量吸收
平均压溃力
数值仿真
压溃试验
thin-walled square tube
ridgeline strengthening
energy absorption
mean crushing force
numerical simulation
crushing test
