Dissection Method of Solid Rocket Motor Chamber Based on Ultrasonic Vibration Sawing

Abstract

Overall dissection and in situ sampling are the most direct and reliable ways to obtain the storage performance degradation of solid rocket motors. However, mechanical cutting poses serious safety risks because grains are regarded as a chemical product. Ultrasonic vibration sawing of diamond wires can be performed in a wide variety of materials. Moreover, this mechanism has a low cutting force and a high cutting precision, produces narrow slits and leads to a low rise in cutting temperature. Thus, this method has application prospects in comprehensive engine dissection. In this work, the main material physical characteristics of the chamber of a nonmetallic case motor were analysed. A four‐parameter orthogonal experimental study with an infrared temperature measurement as the control parameter was conducted. The safety parameters during the shell cutting were preliminary determined. The cutting temperature inside the solid propellant block was measured with an embedded microthermocouple. The cutting process parameters were then checked. The safety of the method was further verified by simulating the motor chamber via an integrated sawing test. Results showed that the ultrasonic vibration sawing method has the advantages of fast cutting speed, low increase in cutting temperature, produces a flat cutting surface and does not lead to stratification in the cutting interface when dissecting the chamber of the nonmetallic case motor. Moreover, this method has potential applications in the engineering practice of storage life research in solid rocket motors.

Long‐Term and Short‐Term Creep Characteristic Analysis for HTPB Propellant

“…Solid rocket motors have the characteristics of long-term storage and one-time use [1]. The propellant grain is the energy and key structural component of motor [2].…”