薄带材浪形缺陷生成与拉伸矫直过程数值仿真

Numerical simulation on the wave-shaped defect generation and tension straightening process of thin strips

基于ABAQUS有限元软件建立了薄带材浪形生成与拉伸过程有限元模型,研究了带材在初应变作用下的浪形缺陷生成规律及其在张力拉伸作用下的应力特性及其变形行为,并进一步分析了浪形缺陷拉伸矫直矫平功效的主要影响因素及其影响规律.薄带钢变形过程可分为浪形生缺陷生成、拉伸矫直和弹性回复三个阶段.针对薄钢带弹性后屈曲浪形和铝带弹塑性后屈曲浪形两类典型浪形形式,研究了浪形缺陷在后屈曲和拉伸变形阶段的浪形陡度变化与系统能量变化规律.研究表明:弹性后屈曲浪形在拉伸矫直过程中浪数和浪高均发生变化,而弹塑性后屈曲浪形仅发生浪高的连续变化.弹性后屈曲浪形矫直后的残余应力分布形式与初始应力分布类似,而弹塑性后屈曲浪形的残余应力分布发生显著差异.浪形缺陷的残余陡度随初始浪形陡度增大而增大,随带厚增加而减小,且弹塑性后屈曲浪形缺陷的矫直效果更为显著.

A mathematical model to describe the wave-shaped defect generation and stretching process of thin strips is established by using ABAQUS to study the stress characteristics and deformation behavior of strips under initial strain. Influencing factors on the straightening effect are analyzed in the tension straightening process. The deformation process of wave-shaped defects is divided into a generation phase, a stretching stage, and an elastic recovery phase. The elastic-buckling wave of thin steel strips and the elastic- plastic-buckling wave of aluminum strips as two typical wave-shaped forms are focused on to investigate the change of wave steepness and system energy. During the process of tension straightening, the number and height of the elastic-buckling wave both change, while the height of the elastic-plastic-buckling wave does continuously only. After straightening, the residual stress distribution of the elastic- buckling wave is similar to the initial stress distribution, while the residual stress distribution of the elastic-plastic-buckling wave makes a significant difference. The steepness of the residual wave increases with the increase of initial wave steepness and decreases with the increase of strip thickness. The straightening effect of the elastic-plastic-buckling wave is more significant.