Research on Visco-hyperelastic Constitutive Model of EPDM.

The constant rate uniaxial tension tests and tension-recover tests are conducted to obtain the accurate mechanical property of the EPDM insulation material. A visco-hyperelastic constitutive model is developed based on the mechanical behavior characteristics of EPDM. The method is established by applying the hyperelastic theory which was established under finite deformation condition in combination with linear viscoelastic theory. Then the way to obtain the model parameters is proposed, which is simple and easy to be generalized. The results show that EPDM has the typical hyperelastic mechanical characteristics, and presents a rate-dependent effect. The visco-hyperelastic constitutive model proposed can describe the uniaxial mechanical property of EPDM accurately. The model can provide a theoretical reference for structural integrity analysis of solid rocket motor made of EPDM insulation material. [ABSTRACT FROM AUTHOR]