6063铝合金薄壁方管耐轴向撞击性能研究

Investigation of axial anti-collapse behavior of square aluminum alloy tube 6063

针对汽车用铝合金构件的安全设计要求,采用关键试验加有限元仿真技术,对6063铝合金薄壁方管轴向耐撞击性能进行了研究.通过轴向静态压缩和落锤冲击试验,获得了该薄壁试件静态和冲击载荷下的力学行为规律.同时应用有限元模型对不同结构尺寸的试件进行了不同速度下的冲击仿真分析,给出了试件变形和载荷预测.研究结果表明,6063铝合金薄壁试件具有良好的吸能性,试件的耐撞性和材料组织、加载速度及结构几何尺寸有密切关系.降低冲击速度、减小构件长细比以及增大壁厚,有利于改善试件屈曲过程的稳定性.作为汽车用缓冲吸能结构,该类薄壁铝合金试件的长细比不宜大于12,壁厚取2 mm,长度在310 mm左右为结构最优.

Aimed at the requirement of safety design of aluminum alloy components in automobiles and employing a key experiment and the simulation technique of finite element, the axial anti-collapse behavior of thin-walled square aluminum alloy tube 6063 was investigated. The pattern of mechanical behavior of this thin-walled specimen under static and impact load was obtained by means of the experiments on axial static compression and drop-hammer impact. Meantime, simulation analysis of the specimen with different configurational dimensions and under different impact speeds was performed by using finite element model so that, the prediction of its deformation and load was given. It was shown by the investigation that such specimen possesses good energy absorbability ; there is a close relationship of anti-collapse ability to the microstructure of material,loading speed, and structural dimension. Lowering of the impact speed and slenderness ratio as well as increasing the wall thickness would be beneficial to improvement of buckling stability. As a damping mechanism for energy absorption in automobiles, the slenderness ratio of its thin-walled tube is to be less than 12, the wall thickness-2 mm, and length-about 310 mm for an optimal construction.