一种新的叠加系统旋转效应的评估指标

针对旋转效应是叠加系统测量不确定度的重要影响因素,提出一种旋转效应的评估指标——力传感器所受的水平附加侧向力的波动量(F_m).基于有限元法,建立了叠加系统旋转效应的测量模型,模拟结果显示增大均力板厚度有利于削弱F_m.通过试验验证,发现F_m越小,旋转效应也越小.在试验力级250 k N处,均力板厚度为6、9和12 mm的叠加系统测量的最大偏差值分别为0.000 59、0.000 49和0.000 28 m V/V.有限元模拟和试验结果验证了评估指标的可行性,同时也为叠加系统的结构优化提供了有效的手段.

A new evaluation index for the rotation effect of a build-up system

The rotation effect is considered as an important factor for the measurement uncertainty of a build-up system. The largest difference (F_m) between the three additional side loads, which horizontally act on the three load cells in the build-up system, was defined as an evaluation index for the rotation effect. Measurement models of the build-up system were created based on the finite element method, and the results revealed that F_m was reduced with the increase of the thickness of the balance structure. The rotation effect was restrained with the increasing of F_m, which was validated by the experimental results. Three deviations including 0.00059mV/V, 0.00049mV/V and 0.00028mV/V were obtained at 250kN, which were corresponded to three different thickness of the balance structure 6mm, 9mm and 12mm respectively. Effectiveness of the evaluation index was verified by the finite element simulations and the tests, which was helpful to improve the structure of the build-up system.