复合推进剂预制裂纹扩展试验研究

采用快速升压法模拟研究固体复合推进剂预制裂纹在火箭发动机点火过程中裂纹扩展情况。建立了快速升压试验装置,开展了密闭升压、有喷管升压条件下固体推进剂裂纹扩展实验,研究了锲型块对裂纹扩展程度的影响。实验结果表明:密闭升压实验中,随着压强的增大,裂纹扩展越剧烈,裂纹深度逐渐加深,宽度加大;增加楔形块,自由体积变小,固体推进剂裂纹扩展程度降低。有喷管升压实验中,随着压强的增大,裂纹扩展加大,但与密闭升压实验相比,裂纹扩展程度变弱。实验表明裂纹扩展随着升压速率的变化而变化,升压速率越大,裂纹扩展现象越明显。

Experimental Research on Crack Propagation of Composite Propellant

The rapid pressure boost method has been used to simulate crack propagation in the solid composite propellant during the process of rocket engine ignition. In order to evaluate the effect of the wedge-shaped block on crack propagation in the solid composite propellant, the device to boost pressure rapidly has been made. Experiments were conducted in two conditions. One is in a close chamber without nozzles and the other is in a chamber with nozzles. The results show that as the pressure increases, the crack growth increases in the first experimental condition. Additionally, the crack growth decreases if the wedge-shaped block is added to reduce the free volume. Compared to the first condition without nozzles, the other condition with nozzles got a weaker crack propagation. In conclusion, the crack growth rate is changed with the pressure rate. The quicker of step-rate increases, the more obvious phenomena of crack propagation.