Influence of the startup and shutdown phases on the viscoplastic structural analysis of the thrust chamber wall

Detailed structural analysis with Robinsonʹs viscoplastic model of the thrust chamber wall has been completed to explain its damage process phase by phase, indicating that under the same level of thermal–structure loadings, the startup and shutdown phases play an important role of the failure. Different startup and shutdown durations were applied to study the phase influence on structural analysis and predicted life. Results reveal that the startup process mainly affects the remaining strain, while the shutdown process contributes more to the remaining stress on the cyclic effect; quick startup and longer shutdown duration conduce to prolong the chamber life and the life can be promoted 22% through reducing start-up duration from 1.5 s to 0.3 s, while 5% through increasing shut-down duration from 0.15 s to 0.9 s.