高g值冲击下聚氨酯缓冲仿真研究

Study on Cushioning Simulation of Polyurethane Under Impact of High g

本文利用霍普金森压杆实验获得聚氨酯的应力应变数据,并采用数据对朱-王-唐(Z-W-T)本构模型中弹性模量、弹性常数以及松弛时间进行参数辨识,发现模型在真实应变0~0.1范围内能较好地表达聚氨酯材料的应力应变关系.同时,研究了聚氨酯缓冲材料的应力衰减特性,获得其应力衰减系数为-0.45.对弹丸整体装配结构进行膛内高过载仿真,并应用仿真结果验证了应力衰减方程,发现相对误差小于10%;双重缓冲防护可将电路板最大应力幅值衰减30%.仿真结果表明,电路板长度方向贴近弹尾部电路板底部0 cm~1.8 cm会受到较大的应力幅值,大于1.8 cm处受到的应力幅值较小,为高g值冲击防护提供了依据.

The stress-strain data of polyurethane was obtained by using the Hopkinson pressure bar test,which was used to analyze the Zhu-Wang-Tang(Z-W-T)constitutive model.And the elastic modulus,elastic constant and relaxation time were then identified.The results show that the model can better express the stress-strain relationship of polyurethane material in the range of true strain from 0 to 0.1.The stress attenuation characteristics of the polyurethane were studied,by which the stress attenuation coefficient was got as-0.45.The overall assembly structure of the projectile was used for the high overload simulation in the cannon,by which the stress attenuation equation was then verified.The results show that the relative error is less than 10%,and the double buffer protection can attenuate the maximum stress amplitude of the circuit board by 30%.According to the simulation results,in the length direction of the circuit board,0 cm-1.8 cm close to the bottom of the circuit board at the tail of the projectile will experience a larger stress,while the rest of the position will experience a smaller one.All the research above provided a basis for protection under high g impact.