Research on the Load-Sharing Principle of a Novel Piezoelectric Dynamometer

Abstract

The range of three-dimensional piezoelectric sensors in two tangential directions, depending on the maximum static friction force generated by axial preload, is usually only one-fifth of the axial preload, or even lower. It greatly limits the application of piezoelectric sensor in those situations where tangential measuring range is equal to or larger than axial measuring range. This article proposes a method that uses split cylindrical pins to realize load sharing only in tangential direction, and then establishes a load-sharing mathematical model based on the radius of cylindrical pin. Finally, Finite Element Method (FEM) is used to analyze load-sharing stability of 10 mm cylindrical pin and split pin. A load-sharing experiment based on a three-dimensional piezoelectric dynamometer with a tangential range of 1kN and an axial range of 5kN is designed. The experimental results indicate that the tangential load-sharing ratios are 21.4% and 23.0%, the axial load-sharing ratio is 81.0%, which is agree well with the results of FEM analysis. It proves that the static measurement accuracy of the piezoelectric dynamometer in axial direction is not affected. Great load-sharing performance in tangential direction but little load-sharing performance in axial direction can be realized by using split cylindrical pins.