中高应变率和不同温度下离子型中间膜的拉伸力学性能及本构关系

THE TENSILE MECHANICAL PROPERTIES AND CONSTITUTIVE RELATIONSHIP OF IONOMER INTERALYER AT MEDIUM-TO-HIGH STRAIN RATES AND DIFFERENT TEMPERATURES

为系统研究中高应变率和不同温度下离子型中间膜的拉伸力学性能,进行了1 s−1~800 s−1和−40℃~60℃下的系列动态拉伸试验。基于试验结果,确定了离子型中间膜的关键力学参数,并着重分析了温度和应变率的影响:随着应变率的升高和温度的降低,离子型中间膜的初始弹性模量、屈服强度和抗拉强度均普遍提高,但极限应变有所降低。基于G’SELL本构模型,建立了离子型中间膜的本构关系,根据试验结果标定了模型参数,模型预测结果与试验曲线吻合较好。采用应力补偿更新算法开发了用户子程序,实现了该文所提出的本构关系在LS-DYNA中的应用,并通过数值结果与试验结果的比较验证了用户子程序的有效性。

To systematically study the tensile mechanical properties of ionomer interlayer at medium-to-high strain rates and different temperatures,dynamic tensile tests are performed at 1 s−1~800 s−1 and−40℃~60℃.Based on the experimental results,key mechanical parameters are identified,and the effects of temperature and strain rate are analyzed.As the strain rate increases or the temperature decreases,the initial elastic modulus,yielding strength and failure strength increase but the failure strain decreases.Based on G’SELL model,the model parameters are calibrated and validated against the test results.Adopting a stress-compensation method,the paper develops a user subroutine to introduce the proposed constitutive equation into the LS-DYNA software.The effectiveness of the user subroutine is validated through the comparison between numerical and test results.