风洞分布式支撑天平测力试验技术研究

采用双尾支撑测量形式的加工、装配误差会使系统内应力过大，影响测量精度。针对某“双机身”飞机CTS 风洞试验气动力测量需求，发展基于多维力天平内置的风洞分布式支撑天平测力试验技术；研制具有消除系统内应力功能的双支撑系统，提出两种6 分量双支撑天平校准及测力方法，并对数据处理和双支撑系统可靠性进行检验加载、对比分析和验证。结果表明：风洞分布式支撑天平测力试验技术能够有效消除双支撑天平系统由于过约束而导致的固有装配内应力，双支撑天平系统各部分连接、测量可靠；两种校准测力方法测量精度相当，均能达到单台应变天平测量误差水平，可满足风洞试验测量精度需求；综合考虑现有校准设备校准能力，最终采用“合成式校准测力”方法进行的风洞试验，获得了满意的试验测力精度。

Experimental investigation on technology of force measurement using a distributed-sting-balance in wind tunnel

According to the demand of the wind tunnel experiment, the aerodynamic force measurement technology using a distributed-sting-balance is developed. As an application instance, a twin-sting-balance measurement system with the function which can eliminate the internal stress of the system is carried out. Two Calibration methods for the six-component twin-sting-balance measurement system are used and discussed, which are the combination calibration method and the integration calibration method, and the verification of the reliability of the twin-sting-balance system design and the calibration methods are also conducted. The results show that the twin-sting-balance measurement system design can eliminate the inherent internal stress caused by the over-constraint of the system effectively. Besides, the twin-sting-balance system can obtain a high force measurement accuracy and precision using both of the two calibration methods, which can meet the requirement of the wind tunnel experiment. Finally, the wind tunnel experiment is conducted with the method of combination calibration taking into account the calibration capability of the calibration rig in CAAA, and a satisfying measurement precision is obtained.