泡沫铝填充薄壁梁斜向碰撞的仿真研究

采用有限元仿真技术研究了泡沫铝填充薄壁梁不同角度斜向碰撞下的吸能特性.分析了泡沫铝密度、壁厚、长宽比等设计参数对临界角和平均碰撞力的影响,并拟合出平均碰撞力和各设计参数及碰撞角度的解析式.结果表明,泡沫铝填充薄壁梁的临界弯折角小于无填充薄壁梁,并且泡沫铝密度对临界角的影响最大.随着横截面宽度从70mm增大到90mm,无填充薄壁梁弯折临界角从6°增大到9°,而泡沫铝填充薄壁梁弯折临界角度则没有明显改变.壁厚越厚泡沫铝填充薄壁梁的弯折临界角越大,但无填充薄壁梁弯折临界角不变.平均碰撞力和碰撞角度存在指数函数关系,且反比于长宽比平方、正比于壁厚和泡沫铝密度的指数幂.

Simulation of Foam-filled Thin-walled Columns Subjected to Oblique Impacts

The energy absorption characteristics of foam-filled thin-walled columns subjected to oblique loads were analyzed with the finite element simulation technology. The influences of foam density, thickness, and aspect ratio of columns on the bending critical angle and average impact force were investigated. The formulation of the average impact force was developed in terms of design parameters and oblique impact angle. The results show that the critical angle of foam-filled columns is less than that of empty columns, and foam-filler density has a great influence on the critical angle. With the increase of cross section width from 70 mm to 90 mm, the critical angle of empty columns increases from 6° to 9°, while that of foam-filled columns does not change significantly. The critical angle of empty columns is not significantly influenced by the wall thickness, while higher wall thickness of foam-filled columns leads to larger critical angle. The average impact force is an exponential function of the impact angle, and is inversely proportional to the square aspect ratio and proportional to the exponential power of the wall thickness and density.