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Acta Aeronautica et Astronautica Sinica ›› 2025, Vol. 46 ›› Issue (16): 431661.doi: 10.7527/S1000-6893.2025.31661

• Material Engineering and Mechanical Manufacturing • Previous Articles    

Generation and release mechanism of residual stress and strain in solid rocket motor propellant grain with pressure cure

Jia WEI1,2, Baoshi YU1,2, Dapeng ZHANG1,2(), Zhibin SHEN1,2, Yongjun LEI1,2,3   

  1. 1.College of Aerospace Science and Engineering,National University of Defense Technology,Changsha 410073,China
    2.Hunan Key Laboratory of Intelligent Planning and Simulation for Aerospace Missions,Changsha 410073,China
    3.Rocket Force University of Engineering,Xi’?an 710025,China
  • Received:2024-12-13 Revised:2024-12-31 Accepted:2025-01-21 Online:2025-02-06 Published:2025-02-06
  • Contact: Dapeng ZHANG E-mail:zhangdapeng@nudt.edu.cn
  • Supported by:
    National Key Laboratory of Solid Rocket Propulsion(2024020404);Independent Innovation Science Fund Project of the National University of Defense Technology(22-ZZCX-077);Independent Research and Cultivation Project for Young Talents of College of Aerospace Science and Engineering, National University of Defense Technology

Abstract:

To investigate the generation and release mechanism of residual stress and strain in solid rocket motor propellant grain with pressure cure, a theoretical model considering the coupling of thermochemical-mechanical multi physics fields during curing and cooling process was developed based on viscoelastic theory, finite difference method, and incremental method. The composition, distribution and evolution laws of residual stress and strain of grain were revealed. The mapping relationships between temperature, degree of cure, residual stress and strain of grain were obtained. The release path of residual stress and strain of grain was optimized. The results showed that the residual stress and strain of grain were mainly caused by the accumulation of three parts: thermal expansion and cure shrinkage during curing stage, and cooling shrinkage during cooling stage. The residual stress caused by three parts accounted for about 5%, 12% and 83% respectively. The residual strain caused by three parts accounted for about -1%, 24% and 77% respectively. During cooling stage, as the temperature of grain decreases, the residual stress and strain linearly increase. Using the proposed theoretical model, the optimal pressure load of pressure cure technology was calculated, which is linearly related to the circumferential elastic modulus of the case. Compared with the conventional pressure cure technology, the optimized technology based on the composition and evolution laws of response can reduce the maximum residual stress and strain during curing and cooling process by an average of about 65.5%.

Key words: pressure cure, solid rocket motor, thermochemical-mechanical coupling, residual stress and strain, generation and release mechanism

CLC Number: