A measurement method of bending–torsion deformation for constant cross-section shaft and rod workpieces

Abstract This paper proposes a novel measurement method for bending–torsional deformation of shaft and rod workpieces with constant cross-sections. The method addresses the challenge of coupled bending–torsion deformation analysis by processing surface profile point cloud data acquired through continuous rotary measurement. A successive iterative algorithm is developed to simultaneously decouple and quantify bending and torsional deformations within a unified computational framework. The effectiveness of the proposed method is preliminarily verified through extensive simulations, and error analysis is conducted based on the simulation results. Experimental validation further demonstrates the method’s effectiveness and superior flexibility compared to conventional methods. The proposed method is characterized by notable generality, including applicability to diverse cross-sections and workpiece dimensions, along with flexibility in implementation. Additionally, the capability for synchronous measurement of bending–torsion deformation is presented as an advantage. Significant potential is demonstrated for applications in precision manufacturing and quality control.