随机参数影响下橡胶密封垫的应力松弛特性

Stress Relaxation Characteristics of Rubber Gasket Under Effect of Random Parameters

摘要:

采用MooneyRivlin超弹性和Prony级数形式黏弹性模型，将有限元结果与试验数据对比，对模型参数进行验证.运用AnsysPDS随机分析模块计算各随机参数对表面接触应力的灵敏度，以及超弹性和黏弹性参数变化对表面接触应力松弛特性的影响.结果表明:参数取值合理;对表面接触应力影响较大的随机参数为α2和C10，α1、τ1和C01的影响次之，而τ2的影响可以忽略不计;松弛主要发生在加载第1天，1年内基本保持稳定；超弹性参数取值越大，应力衰减越小，黏弹性参数则相反.

关键词:橡胶密封垫; 应力松弛; 随机有限元法; 灵敏度分析

Abstract:

The MooneyRivlin hyperelastic model and the Prony series viscoelastic constitutive model were used to verify the selected calculation parameters by finite element analysis compared with stress relaxation test data. Then, the AnsysPDS module was used to analyze the sensitivity values of all random parameters to surface contact stress and the influence of hyperelastic and viscoelastic parameters on the surface contact stress relaxation. The results show that parameter values are reasonable. Random parameters which have great influence on the surface contact stress are α2 and C10, followed by α1、τ1 and C01, and the effect of τ2 is negligible. Relaxation mainly occurred on the first day of loading and remained basically stable within 1 year. The larger the values of hyperelastic parameters, the smaller the stress attenuation is, and the opposite of viscoelastic parameters.

Key words:rubber gasket; stress relaxation; stochastic finite element method; sensitivity analysis