Deformation prediction and experimental validation of three-point bending straightening process for ball screws with FEM

Ball screws, as high-precision transmission workpieces, are widely used in CNC machine tools and precision equipment, where straightness directly affects transmission accuracy and performance. However, bending deformation is easily induced during manufacturing and service, leading to reduced accuracy and stability. Straightening is therefore regarded as an essential method to ensure geometric accuracy and service performance. In this paper, the three-point bending straightening process is investigated through theoretical analysis, finite element simulation (FEM), and experimental validation. Based on elastoplastic mechanics, the bending behavior of shaft-like workpieces under concentrated loading is analyzed, and the deformation behavior during loading, unloading, and springback are clarified. A finite element model is then established, in which material properties, contact interactions, and boundary conditions are reasonably defined, and the deformation behavior under different pressing strokes is simulated. Furthermore, straightening experiments are conducted to obtain deformation distributions under various loading conditions, and the results are compared with simulations. The results of this paper provide theoretical guidance and technical support for the optimization of straightening process parameters, forming quality control, and the improvement of finite element modeling methods, and are of significant engineering value for enhancing the manufacturing quality and service performance of high-precision transmission components.