Effect of Pressure on Mechanical Properties of Composite Propellant

Abstract

AbstractComposite propellant must possess sufficient structural capability to withstand the various loading conditions. Several attempts are made worldwide to evaluate mechanical properties of composite propellant at different temperatures and strain rates but effect of pressure has not been yet fully elaborated. In the present study, effect of pressure on mechanical properties of composite propellant was evaluated and discussed to obtain the best possible simulation of firing phenomena. The Universal Testing Machine (UTM) was used to characterize the mechanical behavior of AP/ Al/ HTPB based composite propellant at different strain rates of 0.001916 s‐1, 0.01916 s‐1, 0.1916 s‐1 and 0.9578 s‐1 at various pressure of 0.1, 2, 3, 5 and 7 MPa. The study reveals that the structural capabilities of studied propellant is increasing with pressure up to a threshold limit and then decreases. The strain capability of studied composite propellant increases with increase in strain rate at a given pressure and it possess maximum stress capability when operated in the pressure range of 4 to 6 MPa. These findings can be used efficiently during the design and development of solid rocket motor and development of a new propellant formulation. Further, the failure boundary envelope has also been generated to study the effect of pressure and strain rate simultaneously.