Structural Integrity Assessment on a Large Solid Booster Propellant Grain
Advanced launch vehicles are being developed for placing relatively large satellites in a geo -synchronous transfer orbit. Propulsion of such launchers can be achieved through large solid boosters, liquid and cryogenic engines. This article deals with the structural integrity assessment on a large booster propellant grain, including its bond lines under service loading conditions (viz., thermal shrinkage, vertical and horizontal storage and internal pressure loads) and finalization of the loose flap requirement for the head end segment (HES), mid segment (MS) and nozzle end segment (NES). Individual segments are analysed for the horizontal storage conditions utilizing 3D grain configurations and estimated slump displacements at the inner propellant port and maximum induced normal stress at the top surface of the propellant /insulation interface. It is observed that (I) The maximum vertical storage slump is nearly thrice the horizontal storage slump whereas maximum interface storage stress is nearly twice that of horizontal storage; (Ⅱ) By supporting the bottom surface (I.e., both the propellant and casing) for the vertical storage, the radial slump towards the center of the axis is nearly twice to that of the case when it is supported only the bottom surface of the casing. It is also noted that 93% of the slump recovers within 4 hours after removal of the propellant support ; and (iii) For horizontal storage conditions, one end face of the bottom propellant support moves axially outward whereas the propellant port top point moves axially inward. To study the ignition transient phase, viscoelastic analysis of the assembled grain has been carried out considering Master Stress Relaxation Modulus (MSRM) curve of the propellant. Structural margins are estimated utilizing the achieved mechanical properties of the propellant grain. Measured vertical slumps are found to be within the expected range. The successful static test of the large solid booster indicated the adequacy of the structural integrity assessment on the designed propellant grain configurations.
RENGANATHAN K. SARMA B.S.V.Rama RAO B.Nageswara SIVASUBRAMONIAN B. NAIR N.Jayachandran
Structural Engineering Entity,Vikram Sarabhai Space Centre,Trivandrum 695022,India
国际会议
2011 International Autumn Seminar on Propellants,Explosives and Pyrotechnics(2011国际推进剂、炸药、烟火技术秋季研讨会)
南京
英文
443-453
2011-09-20（万方平台首次上网日期，不代表论文的发表时间）