Dynamic impact deformation of composite propellant under rapid pressurization using high-speed camera

To understand the operational process in a combustion chamber, the main factor governing the interior phenomena of the SRM is the flow of high pressure gases. For the structural integrity evaluation of solid propellant grains under rapid pressurization load, a small SRM tester was designed to follow the deformation of the propellant under cold flow conditions, to investigate the viscoelastic nature of the propellant. Here the pressurization is created by a gas supply system using nitrogen gas, high-speed camera is used to record the data, which is used then to convert these data into displacement vector and strain rate. Two pressure transducers were used to measure the pressure in the head-end and the aft-end of the tester. Results show that during this test deformation is detected and pressure difference along the tester is measured, the data acquisition system shows two different pressurization curves. The deformation is dependent on the pressure difference and increases with this difference; we successfully measure the strain rate for each test. When the deformation is smaller the strain rate is higher, and when the deformation is larger, the strain rate is smaller which could be interpreted by the nonlinear viscoelastic behavior of the propellant.