压电测力仪尺寸参数对测试精度影响研究

针对大量程比、小力值压电测力仪，分析了测力仪结构尺寸对测试精度的影响。采用理论与有限元分析相结合的方式分析可得，测力仪自身刚度不足引起的变形将增大测力仪向间干扰，降低测试精度。测力仪上盖厚度、中心孔径及传感器跨距尺寸参数是导致测力仪刚度不足，影响测力仪测试精度的关键因素。通过对某小力值测力仪进行尺寸参数优化设计，各项固有频率均在4 kHz以上，动态性能优良；标称力值作用下，最大向间干扰为3.33%，测试精度提高33.4%

Study on Influence of Size Parameters of Piezoelectric Dynamometer on Test Precision

For a large range of ratio and small force piezoelectric dynamometer, the influence of the structure size on the test accuracy is analyzed. The result shows that the deformation caused by the insufficient stiffness of the dynamometer itself leads to the increase of inter interference between dynamometers and the decrease of test accuracy by combining the theory and finite element analysis. The upper cover thickness, the central aperture and the sensor span parameter are the key factors that cause the stiffness of the dynamometer to be insufficient and affect the accuracy of the dynamometer test. By optimizing the size parameters of a small force dynamometer, all the natural frequencies are above 4 kHz, and the dynamic performance is excellent. Under the action of nominal force, the maximum inter interference is 3.33% and the test accuracy is improved by 33.4%.