A constitutive model and FEA of rubber under small oscillatory load superimposed on large static deformation

摘要

A heuristic constitutive equation and an FE formulation for rubber under small oscillatory loads superimposed on large static deformations are presented. The viscoelastic constitutive model, is implemented in an FE code to analyze the dynamic characteristics of rubber elements under general loading conditions. Dynamic tests in which the rubber specimens endure steady-state harmonic motion superimposed on large static deformation are performed in order to verify the proposed model. Compression and complex-stress tests are included in the tests to check the proposed model under multi-axial stress states. The FEA results are compared with the experimental results. The proposed model successfully predicts dynamic stiffness peak in the complex-stress test, which cannot be explained by conventional models. The model shows a better performance than existing models in predicting the behavior of rubber specimens that are subject to complex pre-strain.