A General Stroke-Based Model for the Straightening Process of D-Type Shaft

Abstract

D-type shaft is widely used in precision machinery products such as motors and intelligent robots. The straightness of the D-type shaft is an important factor influencing its machining accuracy and dynamic performance, which is normally improved by the three-point pressure straightening process. This paper proposes a general stroke-based model to predict the relevant parameters for the straightening process of D-type shaft, considering the bending deformations in three dimensions. The distribution of stress and strain inside the D-type shaft during the straightening process in arbitrary position of the cross section and the bending moment are analyzed by using linear hardening material model. The relationship between deflection and the internal stress on the loading position is explored, and a straightening stroke model of D-type shaft is obtained. The correctness of the stroke-based straightening model has been validated by finite element method (FEM) simulation analysis and bending experiments. The results show that the proposed model can improve the accuracy and efficiency of the D-type shaft straightening process. Furthermore, it provides a novel method for the modelling of the straightening process regarding the special shaped bar stock.

Analytical Modeling for Mechanical Straightening Process of Case-Hardened Circular Shaft

“…However, springback and residual deformations were not considered in their studies. In a similar vein, Lu and Zang et al [5] and Lu and Ling [4] developed analytical stoke displacement prediction models for D-shaped shafts and rectangular bars, respectively. The residual deflection was assumed to be the subtraction of pure elastic from total deflection.…”

“…Many research efforts [2][3][4][5][6][7][8] have been made in the past focusing on bend straightening, including analytical, numerical, and experimental studies. Li and Xiong et al [2], and Li and Zou et al [3] developed a mathematical straightening model based on elastoplastic bending theory which was capable of estimating the stoke displacement of a shaft under three-point bend straightening.…”

“…Kim et al [8] used fuzzy self-learning to calculate the bending curvature of the yaw axis. Note that all of the research works [2][3][4][5][6][7][8] that have been conducted were based on a uniform shaft material. However, the case-hardened shaft has a harder surface layer with much higher yield stress and limited ductility compared to its core material.…”

Billet Straightening by Three-Point Bending and Its Automation

“…This article is devoted to the issue of billet straightening, where the second type of straightening is commonly used. The principle of this straightening type relies on three-point bending [ 14 , 15 ], which is more accurate and admits higher dimension variability of straightened billets cross-sections [ 16 ]. In ironworks, three-point bending is a necessary operation performed before grinding billets.…”

Special Issue “Advances in Machine Learning and Deep Learning Based Machine Fault Diagnosis and Prognosis”

“…Other innovative fault diagnosis and failure prognosis techniques are presented in this book [7][8][9], such as analytical redundancy [10], data-driven analytical redundancy [11], and cyclostationary analysis [12], with applications in microelectronics, rotating machines and polymer electrolyte fuel cell.…”