非线性材料仿真精度提升的研究(三)——本构模型的选择

Research on improving the simulation precision of nonlinear material(III)-selection of constitutive models

为了提升非线性材料的仿真精度,针对不同本构模型定义橡胶材料的仿真精度进行研究,对比采用Neo-Hookean模型、Mooney-Rivlin模型、Yeoh模型、Ogden模型、Polynomical模型、Arruda-Boyce模型定义材料进行仿真的误差。首先针对标准压缩试样进行轴向压缩试验,得到轴向压缩的应力应变数据;其次将数据输入仿真软件中,采用不同本构模型进行数据拟合,得到模型参数,定义橡胶材料;然后对压缩试验进行仿真模拟,将得到的应力应变结果与试验数据进行对比,得出各模型的精度;最后针对空调室外机箱体脚垫进行仿真,选取最适合定义脚垫的本构模型。结果表明:采用Mooney-Rivlin二参数模型定义橡胶材料进行仿真,与测试结果的误差最小为3.2%,为后续非线性仿真提供了精度保障。

In order to improve the simulation precision of nonlinear materials,the simulation accuracy of different constitutive models of rubber was studied,and compares the errors of using Neo-Hookean model,Mooney-Rivlin model,Yeoh model,Ogden model,Polynomial model,and Arruda-Boyce model to define materials for simulation.Firstly,conduct axial compression tests on standard compression specimens to obtain stress-strain data under axial compression.Secondly,input the data into the simulation software,use different constitutive models for data fitting,obtain model parameters,and define rubber materials.Then simulate the compression test and compare the obtained stress-strain results with the experimental data to obtain the accuracy of each model.Finally,simulation was conducted on the outdoor chassis foot pad of the air conditioner,and the most suitable constitutive model for defining the foot pad was selected.The results show that using Mooney-Rivlin two parameter model to define rubber materials for simulation has a minimum error of 3.2%compared to the test results,providing accuracy assurance for subsequent nonlinear simulation.