Magnetic Sensor Array for Determining the Assembly Torsion and Preload of a Bolted Joint

In this paper, we present an innovative concept for determining the assembly preload of a bolted joint. The torsion of the bolt is recorded as a measured variable. Two measurement methods are presented for this task. They are applied simultaneously and compared with each other. The optical method allows high accuracy and is suitable for test benches and characterization of screw parameters. The magnetic measuring method is suitable both for the test bench and for measurements in the practical application of bolted joints. The required measuring accuracy and robustness against geometric misalignment can be achieved by a magnetic sensor array. This offers many advantages over a single angle sensor. A test bench is presented on which both methods are applied simultaneously. Experimental results are shown and compared for verification. As a next development objective, a concept for a tool integrating a magnetic sensor array for torsion measurement is proposed.