Experimental study on self-heating phenomena of CMDB/HTPB propellant under intermediate strain rate compression load

Abstract

Self-heating behaviour of solid propellants under intermediate strain rate compressive loading have been studied. Effects of two intermediate strain rate (1 s-1 and 150 s-1) of the CMDB/HTPB propellants were investigated. The compression test was conducted using a hydraulic testing machine and the self-heating temperatures were measured by an infrared camera. The results show the following: (1) For CMDB propellant, the surface temperature of specimens rapidly increased at the initial period, then decreased due to the movement of the high temperature region caused by deformation, and then increased again. Finally, the surface temperature slowly decreased due to heat transfer to the surroundings. Infrared thermography showed the formation of a hot spot. Cracks were initiated and gradually expanded to the interior area during compression. (2) For HTPB propellant, the surface temperature of specimens increased slightly. Compared with CMDB specimens, there was no significant damage to HTPB specimens. (3) For both CMDB and HTPB propellants, the temperature distribution of specimens was non-homogeneous. At the centre of the specimen surface, the temperature is the highest. The self-heating temperatures of propellant increased with increasing the strain rate. However, the difference is slight for HTPB propellant, whereas it is considerable for CMDB propellant.