薄壁槽钢零件辊弯成形边波产生机理及影响因素

Mechanisms and influences of edge-wave in roll-forming for thin-walled channel steel parts

薄壁槽钢零件辊弯成形容易出现边波,影响其成形质量。通过对U型薄壁槽钢零件辊弯成形过程进行正交有限元数值模拟,分析U型薄壁槽钢零件辊弯成形后的应力应变,研究了薄壁槽钢零件辊弯成形边波产生的机理,分析了零件材料的屈服强度σ_s、辊弯成形道次n、零件翼缘高度h和材料厚度t等因素对辊弯成形边波波动量Δy的影响。研究结果表明,边波产生的机理为零件翼缘部位各点产生了纵向应力和不可恢复的纵向塑性应变,且其大小沿翼缘长度方向(纵向)及高度方向均不相等;各因素对边波波动量Δy的影响程度依次为零件翼缘高度h>材料厚度t>屈服强度σ_s>辊弯成形道次n,随屈服强度σs和材料厚度t的增加边波的波动量Δy减小,随零件翼缘高度h的增加边波波动量Δy增大,随辊弯成形道次n增加,波动量Δy先减小后增大。这为合理设计类似薄壁零件的辊弯成形工艺提供了指导。

Edge-waves easily happen in the roll-forming process of thin-walled channel steel parts,which greatly influences the forming quality.After analyzing the stress and strain of the U thin-walled channel steel parts by orthogonal finite element numerical simulations of the roll-forming,the mechanisms of edge-wave in roll-forming were studied.Then,the influences of the material yield strength（σ_s）,the forming pass（n）,the channel steel flange height（h）and the thickness of the material（t）on the edge-wave fluctuation（Δy）were analyzed.The main results showed that the edge-wave was generated due to the longitudinal stress s11 and the unrecoverable plastic strains on each point of thin-walled channel flange,and they were different along the part length and along the flange height.The influences of the mentioned four factors on the edge-wave fluctuation（Δy）were also found to be h〉t〉σ_s〉n.Specifically,theΔydecreases with the increasing ofσsand t,increases with larger h,and first decreases then increases with the increasing of n.This study can provide guidance to design reasonable roll-forming process for the similar thin-walled channel steel parts.