An investigation on the bending straightening process of D-type cross section shaft. (October 2017) - Pei, Yong-Chen
Highlights: Bending straightening process of side-cut and flat-cut D-type shaft is modeled. D-type shaft straightening prediction model is built by elastic-plastic relation. Stress and deformation models are presented for straightening process simulation. Two methods are presented for curvature conversion during straightening process. Experimental research is carried out to verify the straightening prediction model. Abstract: D-type cross section shaft is widely used in many industrial fields. As a crucial factor, the shaft straightness has potential significant impact on its working performance, thus the bending straightening process becomes an essential correction step in shaft manufacturing. With a piecewise linearized elastic-plastic stress-strain relation, the bending straightening process of both side-cut and flat-cut D-type cross section shaft is modeled and deduced as a straightening prediction model. The prediction model can provide an accurate and practical relation between the straightening press curvature and the initial bending curvature. For the straightening process simulation, systematic D-type shaft stress and deformation models are built by using classic principle of material mechanics. Three-point parabola method and parabolic fitting method are both proposed for the curvature conversion in the straightening process. To verify the theoretical straightening prediction model, some specialized D-type shaft specimens are designed and manufactured, and a parameter calibration method of straightening prediction model is proposed. Finally, experimental research and comparison analysis are carried out to verify the correctness and feasibility of the straightening prediction model, and a straightening process flowchart is presented as an application guideline of current models and methods. Graphical abstract: