SOLID ROCKET PROPELLANT GRAIN STRUCTURAL ANALYSIS 

Nikola Gligorijevic

Abstract:

Solid rocket motor propellant grain failure due to various loads acting from the moment of production and continuously during storage and use, can lead to undesirable working regime changes or motor explosion. Solid rocket propellant is a viscoelastic material with mechanical properties highly dependent on the temperature and strain rate, degrading over time due to chemical aging and damage accumulation, yielding a limited service life.

Evaluation of the propellant grain structural integrity differs from that of elastic bodies. This paper defines a possible procedure of structural analysis, method of uniaxial mechanical characterization of propellant, determining the aging law and cumulative damage law, the processing of data, mathematical modelling of the load and the selection and verification of the failure criteria and the procedures for determining the failure probability, constituting the basis for assessing the reliability and service life of the rocket motor.

Key words: rocket motor, propellant grain, solid rocket propellant, mechanical properties, structural analysis, viscoelasticity, failure, reliability, aging, service life.