不同温度下橡胶的动态力学性能及本构模型研究

Research of Dynamic Mechanical Behavior and Constitutive Model of Rubber Under Different Temperatures

利用带有温度调控装置的SHPB(Split Hopkinson Pressure Bar)试验装置和岛津材料试验机,测定了CR橡胶在不同温度(-20℃~50℃),不同应变率(5×10-3/s^3×103/s)条件下的应力应变曲线。结果表明:CR橡胶的力学性能具有温度敏感性和应变率敏感性,两者有一定的等效性,且在动态条件下,-20℃时的应力应变曲线表现出向“玻璃态”转变的特性。本文在以前研究者提出的率相关本构模型的基础上进行了改进,同时考虑了温度效应的影响,提出了一个能描述CR橡胶在不同温度和应变率下的一维压缩力学行为的本构模型,该模型和试验数据有很好的一致性,为数值模拟提供了重要的依据。

Stress-strain curves of CR rubber under various strain rates （5 × 10^-3～3 × 10^3/s） anu various temperatures （-20℃～50℃） are obtained through tests using the Split Hopkinson Pressure Bar （SHPB） and Shimadzu universal testing machine equipped with temperature controllers. The obtained results show that the mechanical behavior of CR rubber is sensitive to temperature and strain rate equivalently. Under dynamic loading condition, stress-strain curves at -20℃ exhibit the transition from ＂rubbery＂ to ＂glassy＂. Based on the rate-dependent phenomenological material model presented by the former researchers, a one-dimension constitutive equation containing the temperature and strain rate effect is modified in this paper. The good agreements between the model descriptions and the experimental results indicate that the model is capable of accurately describing the strain-rate and temperature dependent mechanical behavior of the CR rubber under uniaxial compressive loading conditions. The proposed model is valuable for numerical simulation.