棱线强化薄壁方管轴向压溃力学特性

Mechanical Properties of Thinwalled Square Tube with Strengthened Ridgelines Subjected to Axial Crushing

摘要:

基于Wierzbicki和Abramowicz提出的方管理想化折叠机构和能量耗散模式，引入棱线与平板的屈服强度比，修正了棱线强化薄壁方管在准静态轴向压溃作用下的能量平衡方程，并推导出了平均压溃力理论预测公式.CAE（computer aided engineering）数值仿真完整再现了稳定压溃阶段棱线强化方管形成一个新折叠单元的塑性变形过程.仿真与理论结果对照表明，理论预测公式可以较准确地预测棱线强化薄壁方管准静态轴向压溃过程的平均压溃力，且最大偏差不超过4.3%；其次，对于截面长、宽、高分别为56, 56,1.0 mm的方管，仅占整个截面周长9.09%的4根强化棱线可使其平均压溃力提升53.8%.

关键词:棱线强化; 折叠单元; 能量耗散; 数值仿真; 平均压溃力

Abstract:

Based on the energy dissipation modes and the ideal folding mechanism presented by Wierzbicki and Abramowicz, a modified energy balance equation was developed for the square tube with strengthened ridgelines subjected to quasistatic axial crushing by introducing a yield strength ratio between ridgeline and plate. Then a theoretical prediction formula of mean crushing force was also derived. CAE (Computer Aided Engineering) numerical simulation completely reproduced the plastic deformation process of a new folding element of square tube with strengthened ridgelines during stable crushing stage. Comparisons between simulation results and theoretical solutions show that the theoretical formula can correctly predict the mean crushing force for square tube with strengthened ridgelines subjected to quasistatic axial crushing, and the max deviation is lower than 4.3%. Secondly, for a specific square tube whose length, width and thickness of cross section is 56mm, 56mm and 1.0mm respectively, four strengthened ridgelines which only occupy 9.09% of perimeter of the cross section can increase its mean crushing force by 53.8%.

Key words:ridgeline strengthening; folding element; energy dissipation; numerical simulation; mean crushing force