S1108-4-5 Development of a New Testing Machine for Torque/Clamp Force Testing for Threaded Fasteners in Accordance with ISO 16047 : Optimization of the Testing Machine Structure for Boosting the Accuracy

Abstract

It is one of the important issues for structural safety to control the clamp force of bolted joints. However, there is no tightening testing apparatus commercially available to evaluate the tightening characteristics for wide variety of fasteners in accordance with ISO 16047. This study aims to develop a new testing machine for torque/clamp testing, which will meet the requirements specified in ISO16047. In this study, the root cause of measuring error is analyzed both experimentally and analytically. Finally, it is found that the torque acting on the preloading bolts may affect the sensitivity of piezoelectric force sensors as well as the inherent characteristics of sensors, and the method to boost the accuracy is proposed.