高速冲击下金属橡胶动态力学特性研究

Research on dynamic mechanical properties of metal rubber under high-speed impact

为探讨金属橡胶在高速冲击环境下的动态力学性能,制备了圆柱实心金属橡胶试件,使用分离式霍普金森压杆(SHPB)开展了金属橡胶的动态压缩试验。分析了金属橡胶动态应力-应变规律,探讨应变速率和弹簧卷外径对金属橡胶的动态弹性模量、动态峰值应力、能量吸收和理想能量吸收效率的影响规律。结果表明,动态应力-应变曲线分为弹性形变阶段、局部塑性变形阶段和破坏阶段,动态弹性模量和动态峰值应力均表现出典型的应变速率效应,且均随弹簧卷外径的增大而减小。此外,随着应变增大,能量吸收性能随应变速率增大而逐渐变好,随弹簧卷外径的减小而逐渐变好。理想吸能效率受应变速率影响很小,但随应变增大而逐渐增高并趋于饱和,其饱和值均大于0.75,弹簧卷外径为3 mm时,金属橡胶的理想吸能效率最优,其饱和值达到0.88,表明金属橡胶材料在高速冲击下有良好的吸能抗冲击作用。

To investigate the dynamic mechanical properties of metal rubber under high-speed impact conditions,solid cylindrical metal rubber specimens were prepared,and dynamic compression tests were conducted using a Split Hopkinson Pressure Bar(SHPB).The dynamic stress-strain behavior of the metal rubber was analyzed,and the influence of strain rate and spring coil outer diameter on the dynamic elastic modulus,dynamic peak stress,energy absorption,and ideal energy absorption efficiency of the material was investigated.The results reveal that the dynamic stress-strain curve can be divided into three stages:elastic deformation,local plastic deformation,and failure.Both dynamic elastic modulus and dynamic peak stress exhibit characteristic strain rate effects,decreasing with an increase in the outer diameter of the spring coil.Furthermore,with increasing strain,the energy absorption performance gradually improves with higher strain rates and smaller outer diameters of the spring coil.The ideal energy absorption efficiency is minimally affected by the strain rate,but it gradually increases with strain and tends to plateau,with saturation values exceeding 0.75.When the spring coil outer diameter is 3mm,the metal rubber demonstrates optimal ideal energy absorption efficiency,with a saturation value of 0.88.This indicates that the metal rubber material exhibits excellent energy absorption and impact resistance under high-speed impact conditions.