基于显式积分技术求解大变形橡胶减振元件非线性准静态刚度的方法

Method for Solving the Nonlinear Quasi-Static Stiffness of Rubber Elastic Component under Large Strain by Explicit Integration Technique

将实验测试时间作为计算的加载时间,能够得到与试验等效的橡胶件准静态刚度曲线;金属部件的模拟采用不影响计算时间步长的刚体单元代替可变形的有限单元,可将计算时间缩短20倍;质量缩放因子取2.3×109,泊松比取0.495,对橡胶件的体积可压缩性进行软化,以达到缩短计算时间和保证计算精度的目的;设置橡胶材料的黏性,能够抑制求解过程中出现的数值振荡现象。仿真计算分析与实验结果表明:与隐式积分技术相比,采用显式积分技术能够使大变形工况下橡胶减振元件非线性准静态刚度仿真计算的收敛性提高30%,而动能与内能之比仅为1.5%;在橡胶件垂向压缩量为0～30mm时,采用显式积分技术得到的仿真计算结果与实验结果基本吻合,误差仅为5.5%。研究结果表明,显式积分技术适合用于橡胶件开发过程中对其大变形工况下准静态刚度的仿真计算。

The test time is taken as the loading time for computation so as to gain the quasi-static stiffness curve of the rubber elastic component equivalent to the test. For the simulation of metal parts, rigid elements which do not influence computation time increments are used for replacing the deformable finite elements, so as to shorten the computation time by 20 times. The mass scaling factor is 2.3×109 and the poisson's ratio adopts 0.495. The volumetric compressibility of the rubber component is softened so as to realize the aim of shortening computation time and guaranteeing computation precision. Numerical oscillation appearing in the solving process can be inhibited because viscoelasticity models are contained in the rubber material parameters. It is indicated by simulation analysis and experimental results that the convergency on the nonlinear quasi-static stiffness simulation of the rubber elastic component under large-strain loading condition can be improved by 30% through adopting explicit integration technique compared with implicit integration technique, and the ratio of kinetic energy and internal energy is 1.5% only. Under 0 to 30 mm of vertical compression amount of rubber elastic component, the simulation results obtained by explicit integration technique are basically coincident to experimental results, and the error is only 5.5%. The research results indicate that, during the development of the rubber elastic component, the explicit integration technique is suitable for the simulation computation on the quasi-static stiffness of rubber elastic components under large-strain loading condition.