The Effect Of Temperature On Thrust Testing System Of Attitude Control Rocket Motor

With the development of spatial technology, the measurement precision of thrust of rocket motor is required higher and higher. In order to meet the precision requirements of small thrust measuring system, it is very difficulty to decrease environment impact, especially the temperature. The heat from rocket motor has a great influence on sensor and measuring system, meanwhile, the zero drift of sensor caused by transient temperature can't neglect. Therefore, it has important significance to study temperature's influence on measuring systems.In this paper, a small-force thrust measuring system and its static/dynamic calibration device are presented. The factors of temperature influence are determined through theoretical analysis. At the same time, the effect of heat conduction and temperature field on measuring system is researched through finite element analysis and experiments. Influence law of temperature on measuring system is obtained. Two piezoelectric sensors are the most important parts in measuring system. With the help of connection structure, the thrust is loaded on the measuring platform and the output voltage of sensors is in proportion to the thrust. In experiment, the front flange's temperature of connection structure is about 80℃, while the temperature of vacuum cabin rises to 50℃. Theoretical analysis shows that the effect of temperature on measuring system mainly influences the mechanical structure. The temperature distribution, stress distribution and deformation of measuring platform and connection structure are calculated by finite element analysis. It accords with theoretical analysis. Through heat conduction experiment and temperature rising experiment, the results of finite element analysis are proved right. The effect of heat conduction on measuring system has been obtained by static calibration and dynamic calibration. Finally, based on theoretical analysis and experimental results, the solutions to the effect of temperature on measuring system are presented as follows: adding heat insulation, water cooling and sealing the platform.Through analysis and experimental results, it shows that the small thrust measuring system can meet the practical requirements. The analysis of temperature influence is reliable and the solutions are feasible. It provides the reliable basis for hot-firing test of the small-force thrust measuring system.