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对夹层玻璃中聚氨酯胶片的动态力学性能进行系统研究,可以为飞机和高铁风挡玻璃抗冲击性能的设计提供可靠的材料数据和模型。利用温度控制的Hopkinson拉、压杆试验装置和微型材料试验机(MTS5587)对聚氨酯胶片在-40~50℃温度范围、0.001~6 500s-1应变率范围内的力学行为进行了系统研究。结果表明:航空透明聚氨酯的力学性能具有明显的温度敏感性和应变率敏感性,随着应变率提高或温度降低,聚氨酯胶片的流动应力和割线模量也相应增加,表现出明显的应变率和温度效应,同时两者可能有一定的等效性。温度从-20℃下降到-40℃时,应力-应变曲线变化显著,表现出向玻璃态转变的特性。在0℃以上的温度时,同应变率下,动态拉伸应力-应变曲线的应力值要低于动态压缩曲线的应力值。而在温度低于0℃时,在同应变率下,动态拉伸应力-应变曲线的应力值则高于动态压缩曲线的应力值。
The systematic study on the dynamic mechanical properties of polyurethane films in laminated glass can provide reliable material data and models for the design of impact resistance of aircraft and high-speed windshield glass. The mechanical behavior of polyurethane film in the temperature range of -40 ~ 50 ℃ and the strain rate of 0.001 ~ 6 500s-1 was systematically investigated by using Hopkinson pull, bar test equipment and micro-material testing machine (MTS5587). The results show that the mechanical properties of aviation transparent polyurethane have obvious temperature sensitivity and strain rate sensitivity. As the strain rate increases or the temperature decreases, the flow stress and secant modulus of polyurethane film increase correspondingly, showing obvious strain rate And the temperature effect, at the same time the two may have some equivalence. When the temperature is decreased from -20 ℃ to -40 ℃, the stress-strain curve changes significantly, showing the transition to the glassy state. At temperatures above 0 ° C, the stress values of the dynamic tensile stress-strain curve at the same strain rate are lower than those of the dynamic compression curve. When the temperature is lower than 0 ℃, the stress of the dynamic tensile stress-strain curve is higher than that of the dynamic compression curve at the same strain rate.