Novel method for wireless measuring the pulling and compressive external-force loaded on the elements connected by bolt

LIU Yan, LI Shuang-xi, CAI Ji-ning, ZHANG Qiu-xiang

(College of Mechanical and Electrical Engineering, Beijing University of Chemical Technology, Beijing 100029, China)

Abstract: Aiming at the limitation that using the tensile stress of bolt could only measure the pulling external-force loaded on the elements connected by bolt,but not the compressive external-force,a high stiffness elastic element was added between two elements connected by bolt,using the wireless strain measurement system, the pulling and compressive external-forces Fe loaded on the element were measured by measuring the pulling force of bolt F from elastic deformation. The bolt for measuring force and the elastic element were designed and manufactured. The compression stress and deformation of the elastic element were analysed with ANSYS and the optimal design was determined by orthogonal design. The calculation model of measurement method was established so that the relationship between Fe and F was obtained. Then the replication experiments that the element was loaded Fe under different pretension were carried out. The results indicate that the groove depth and the number of single-sided grooves are the key factors that affect the performance of elastic element. The pulling and compressive external-forces loaded on the element can be measured accurately in real time,and the relationship between Fe and F is linear.