Fatigue Analysis of Flexible Joint Elastomers Combining Ogden Second-Order Constitutive Model with Cracking Energy Density

As the core component of flexible nozzle on solid rocket motors, joint relies shear deformation its silicone rubber elastomers to achieve a large vector angle, and is prone fatigue failure when working under high pressure. Aiming resolve elastomers, cracking energy density (CED) method was introduced into analysis joints. A convenient integral formula for calculating CED derived from Ogden second-order constitutive model. The at maximum value first principal elongation 12.3 MPa 6° swing angle calculated by finite element (FEA), then life prediction conducted. results show that can better predict plane orientation compared with SED. also efficiently accurately obtain distribution dangerous area load. ratio predicted measured 1/1.12 within double dispersion factor. crack location agree well test result. provide theoretical reference structural reliability design