冲击载荷下多胞元薄壁结构的动态压溃行为研究

Dynamic crushing behaviors of multi-cell thin-walled structures under out-of-plane impact

为了提高薄壁结构的动态承载能力和能量吸收特性,基于弯曲主导型和拉伸主导型两类能量吸收结构的优点,构建了多胞元薄壁结构模型。利用显式动力有限元方法,研究了不同冲击载荷下多胞元薄壁结构的动态压溃响应和比能量吸收能力。研究结果表明,除了冲击速度,多胞元薄壁结构的动态压溃行为还受到肋板间夹角和冲击角度的影响。在相同相对密度和冲击速度下,多胞元薄壁结构的动态承载能力明显高于空心薄壁圆管。随着肋板间夹角的增大,多胞元薄壁结构的动态承载特性和比能量吸收能力明显提高,冲击载荷效率也相应增加。需要指出的是,当肋板间夹角增大到45°时,比吸能变化不再明显,试件具有较好的冲击载荷一致性。

In order to improve the dynamic bearing capacity and energy absorption characteristics of thin-walled structures,considering and utilizing the advantages of bending-dominant and tension-dominant structures,a kind of multi-cell thin-walled structure model was established.The dynamic collapse responses and specific energy absorption ability of the multi-cell thin-wall structures were numerically investigated under different impact velocities by means of the explicit dynamic finite element analysis(EDFEA).The results show that beside the impact velocity,the dynamic collapse behaviors of the multi-cell thin-wall tubes are also affected by the ribbed angle and the impacting angle.Under the condition of the same relative density and impact velocity,the dynamic bearing capacity of the multi-cell thin-wall tubes is obviously higher than that of hollow tubes.With the increase of the ribbed angle,the dynamic bearing characteristics and specific energy absorption ability of the multi-cell tubes are improved obviously,and the impacting efficiency is also increased correspondingly.It should be noted that when the ribbed angle is greater than or equal to 45°,the specific energy absorption ability is altered no longer distinctly.Moreover,the multi-cell circular tubes have better crushing load uniformity.