非线性材料仿真精度提升的研究(一)——试验类型对比

Research on improving the simulation precision of nonlinear material(Ⅰ) comparison of test types

为了提升非线性材料的仿真精度,针对超弹性材料本构模型Mooney-Rivlin的常数进行研究,旨在对比进行单轴拉伸、压缩试验得到的常数是否一致。首先制作标准拉伸、压缩样条,分别进行单轴拉伸、压缩试验,得到变形-拉/压力数据;其次针对数据进行处理,得到真实应力应变曲线;然后将拉伸/压缩得到的应力应变曲线分别输入仿真软件中进行数据拟合,得到两参数Mooney-Rivlin模型常数C10和C01,并对比两组常数的一致性;最后进行非线性仿真分析,将仿真得到的应力应变曲线与测试结果进行对比,以验证模型的精度。结果表明:进行拉伸与压缩试验得到的模型常数不一致,需根据具体受力情况确定采取的试验类型,为后续的非线性材料定义及仿真工作提供了试验依据。

In order to improve the simulation precision of nonlinear materials,focuses on the constants of the Mooney-Rivlin constitutive model for hyperelastic materials,aiming to compare whether the constants obtained from uniaxial tensile and compressive tests are consistent.Firstly,standard tensile and compression splines are made and subjected to uniaxial tensile and uniaxial compression tests to obtain deformation tension or pressure data.Secondly,process the data to obtain the true stress-strain curve.Then input the stress-strain curves obtained from tension or compression into the simulation software for data fi tting to obtain the Mooney-Rivlin model constants C10 and C01,and compare the consistency of the two sets of constants.Finally,a nonlinear simulation analysis is conducted to compare the stress-strain curve obtained from the simulation with the test results to verify the accuracy of the model.The results show that the model constants obtained from tensile and compressive tests are inconsistent,and the type of test to be adopted needs to be determined based on the specifi c stress situation,which provide experimental basis for subsequent material defi nition and simulation work.