关键词: 汽车前轴, 脱碳, 梯度夹层梁, n阶剪切变形理论, 弯曲分析

Abstract: During the hot forging and heat treatment processes of the automotive front axle, decarburization occured on the surfaces of the material, leading to change in the mechanics properties of the decarburized layer with varying depths. This phenomenon significantly impacted the bending performance of the front axle under load. A segmented function was used to create a graded variation in surface functionality on both sides of the axle, resulting in a simply supported sandwich beam with uniform internal properties. The bending behavior of the beam under two-point loading was investigated using the n-order shear deformation theory. The displacement field control equation was derived using the principle of virtual work, The Navier analytical method was used to obtain the bending behavior of a beam under simply supported boundary conditions, and compared with examples in the literature. The results indicate that the n-order shear deformation theory has good accuracy and reliability. The deflection and rotation of the beam increase with the increase of the decarburization index k, and reach quasi-steady state at k≈10. When the depth of decarburization is greater than 5 mm, the stress caused by the bending of the beam is more strongly influenced by the  thickness of the decarburized layer than by the height change. When the depth of decarburization on both sides is asymmetric,  the physical neutral surface migrates. The bending deflection and rotation of the beam decrease with the increase of thickness and width, but the change in beam thickness has a greater impact.

Key words: automotive front axle, decarburization, graded sandwich beam, n-order shear deformation theory, bending analysis