Research on Axial Strength Distribution of Variable Cross-Section and Variable Wall Thickness Rotary Forging Shaft

以某变截面变壁厚等速万向传动中间旋锻轴为研究对象，其在旋锻过程中由于加工硬化的作用，毛坯经过旋锻后不同截面的加工硬化程度不同，导致其强度也不同。为了得到旋锻后旋锻轴的轴向强度分布，文章采用理论、仿真和试验相结合的方法，首先根据外径和壁厚的不同将旋锻轴分为十个区域，并根据旋锻轴各区域的变形量计算其截面等效应变，结合材料加工硬化曲线得到各区域旋锻后的强度变化，经过数据修正拟合得到旋锻后旋锻轴的轴向强度分布。然后通过Deform仿真分析典型区域旋锻后的等效应力及应变来验证理论求解的准确性；最后对典型区域进行硬度测试进一步验证理论与仿真分析的合理性。硬度测试结果与理论计算很接近，表明采用分段来计算旋锻轴轴向强度分布是可行的。Taking a variable cross-section, variable wall thickness, and constant velocity universally drive intermediate forging shaft as the research object; because of work hardening during the forging process, the work hardening degree of different sections of the blank after forging is different, resulting in different strengths. To obtain the axial strength distribution of the forged shaft after forging, a combination of theory, simulation, and experiment was used. Firstly, the forged shaft was divided into ten regions based on the different outer diameters and wall thickness. The equivalent strain of the cross-section was calculated based on the deformation of each region of the forged shaft. The strength changes of each region after forging were obtained by combining the material work hardening curve. After data correction and fitting, the axial strength distribution of the forged shaft after forging was obtained. Then, the accuracy of the theoretical solution is verified by analyzing the equivalent stress and strain of the typical area after forging through Deform simulation. Finally, hardness testing was conducted on typical areas to further validate the rationality of theoretical and simulation analysis. The hardness test results are very close to the theoretical calculations, indicating that it is feasible to use segmented methods to calculate the axial strength distribution of the rotary forging shaft.