压电三向测力单元的精度提高方法研究

随着动态力测试量程的不断增加以及对测试精度要求的提高,压电测试技术的关键性作用日益凸显,并被广泛应用于重载设备以及航空航天的矢量力测量中.针对压电三向测力单元装配及施加预紧力过程中出现的上下压块偏转、不同轴等问题,基于力的分载原理对误差进行了量化,建立了测力单元的自预紧误差理论模型,并设计了新型的装配夹具,进行了两种夹具装配下的测力单元角度偏转测试实验以及静态标定实验.实验结果表明,使用新夹具装配的测力单元测试精度明显得到很大提高,相间干扰最大值由6.06％减少为2.97％,为后续测力单元的精度提升途径以及相应的结构研制提供了理论支撑.

Research on methods of improving the precision of piezoelectric force measuring unit

With increase of the dynamic force test range and the improvement of test accuracy requirements, the key role of piezoelectric test technology becomes gradually prominent, which has been widely used in heavy-duty equipment and aerospace vector force measurement. In the process of assembling and applying preload of the piezoelectric three-way force measuring unit, problems such as the deflection of the upper plate and lower plate and the different axis incurred. Based on the load sharing principle of force, this paper quantifies the error and establishes a theoretical model of the self-preload error of the force measurement unit. A new type of assembly fixture is designed, and the angle deflection test experiment and static calibration experiment of the force measuring unit assembled with two types of fixtures are carried out. The experimental results show that the test accuracy of the force measurement unit assembled with the new fixture has been significantly improved, and the maximum value of interphase interference is reduced from 6. 06% to 2. 97%, which provides theoretical support for the improvement of the accuracy of the force measurement unit and the development of related structures.