球头弹丸低速冲击下薄板大变形的理论计算

Theoretical calculation of large deformation for thin plate impacted by hemispherical-nosed projectile with low-velocity

为研究球头弹丸低速冲击下薄板塑性大变形的现象,结合弹道冲击试验,对球头弹丸低速冲击下薄板的变形模式进行了分析.在此基础上,根据球头弹丸低速冲击下薄板的变形特点,基于刚塑性假定,采用动力学方法结合应力波传播理论提出了确定靶板隆起变形区大小的计算方法,通过将球头弹丸低速冲击薄板的过程分为隆起变形和碟形变形2个阶段,利用能量守恒原理建立了球头弹丸低速冲击下薄板塑性大变形的理论计算模型,并与本文及相关文献试验结果进行了比较.结果表明:理论计算得到的隆起变形区大小以及靶板最大变形挠度均与试验结果符合较好,工程上可利用所建立的理论计算模型对球头弹丸低速冲击下薄板的塑性大变形进行合理的预测.

To analyze the deformation mode of thin plates impacted by a hemispherical-nosed projectile at low velocity,a method was proposed to determine the radius of bulging region by adopting dynamics method combined with stress wave propagation theory on the basis of rigid-plastic assumption.Based on the energy conservation principle,a model was developed to calculate the ultimate plastic deformation of thin plates under low-velocity impact of hemispherical-nosed projectiles by dividing the deformation process of the target plates into bulging deformation and dishing deformation stages.Results obtained from theoretical calculations were compared with experimental results from the present test and related literature.It is shown that theoretical predictions are in good agreement with the experimental results in terms of the radius of bulging region and the ultimate maximum deflection of the target plate.The developed model can be employed to predict the large plastic deformation of thin plates subjected to low-velocity impact by hemispherical-nosed projectiles in engineering.