Simulation Method for the Characterisation of the Torque Transducers in MN•m range

Abstract

MN•m torque measurement in wind turbine test benches and in the field is influenced by specific system-dependent parameters (e.g. rotational speed, multi-axial operation loads or deformation). Each of these parameters have a share in the torque measurement uncertainty budget. FEM simulation of the torque transducers provides a flexible and time-efficient method for the quantification of these influences. This paper describes a method for the characterisation of the torque transducers (body and strain gauges) by FEM simulation. The main focus is to give the recommendation for the selection of the FEM parameters (e.g. element type, mesh density), modelling of the strain gauges and connection between strain gauges and transducer body as well as for determination of material properties. The introduced simulation method is exemplarily deployed and validated on a self-designed 4 kN•m torque transducer and can be adapted on the MN•m torque transducers. The validation and measurement investigations have been executed on a 4 kN•m torque test rig under different temperatures (20°C, 40°C, 60°C), strain gauge adhesives (cyanoacrylate, methacrylate, epoxy resin) and various torque steps. The compiled results are a part of the EU and EURAMET funded project "Torque measurement in the MN•m range" [1].