液氧箱后底静应力测量系统设计与应用

Design and Application of the Static Stress Measurement System for Bottom End of Liquid Oxygen Tank

为了验证新材料新工艺在运载火箭液氧箱后底中应用的可行性和安全性,针对承压能力这一重要指标,设计了液氧箱后底静应力测量系统。考虑到内表面应力测试需要在水下进行,提出了应变片水下密封的方法,设计了应变片信号传输线缆密封引出的堵头。为了消除温度以及导线电阻对测量精度的影响,采用了半桥温度补偿和导线误差修正的方法。实验证明,测量系统能够用来检验焊缝质量,为新工艺新材料的应用提供了可靠的试验数据和试验方法。

To validate the feasibility and security of applying new materials and new process techniques for bottom end of carrier rocket liquid oxygen tank,in accordance with the critical index of pressure capacity,the static stress measurement system for bottom end of liquid oxygen tank has been designed. Considering the stress tests of inner surface need to be conducted under the water,the underwater sealing method for strain gauge is proposed,and the leading plug for the sealed signal transmission cable of strain gauge is designed. In order to eliminate the influence of temperature and wire resistance on the measurement accuracy,the methods of half-bridge temperature compensation and correction of wire error are adopted. The experiments show that the weld quality can be inspected by the measurement system; these provide reliable experimental data and test methods for application of new materials and new process techniques.