VISCOPLASTIC ANALYSIS OF AN EXPERIMENTAL CYLINDRICAL THRUST CHAMBER LINER

A viscoplastic stress-strain analysis of an experimental cylindrical thrust chamber is presented. A viscoplastic constitutive model incorporating a single internal state variable that represents kinematic hardening was employed to investigate whether such a viscoplastic model could predict the experimentally observed behavior of the thrust chamber. Two types of loading cycles were considered: a short cycle of 3.5-s duration that corresponded to the experiments and an extended loading cycle of 485.1-s duration that is typical of the Space Shuttle Main Engine (SSME) operating cycle. The analysis qualitatively replicated the deformation behavior of the component as observed in experiments at NASA Lewis Research Center. These experiments were designed to simulate the SSME operating conditions. The analysis also showed that the mode and location of failure in the component may depend on the loading cycle. The results indicate that using viscoplastic models for structural analysis can lead to a more realistic life assessment of thrust chambers.