高强钢热冲压成形破裂行为的变形速率效应

发布时间：2018-03-08 04:34

本文选题：高强钢　切入点：热冲压　出处：《锻压技术》2017年01期 　论文类型：期刊论文

【摘要】：以汽车热冲压件的典型特征结构——U形梁为研究对象,将BR1500HS钢高温破裂准则嵌入热冲压成形有限元模型中,实现了对高强钢板高温破裂行为的有效预测。基于预测模型,揭示了变形速率对板料破裂起始时刻、位置及扩展方向的影响。结果表明:随变形速率的增大,起裂时刻缩短,起裂位置变化不明显;起裂位于U形梁一端的侧壁,裂纹沿U形梁纵向随形扩展,随后另一端侧壁处开始发生二次破裂,裂纹也沿U形梁纵向随形扩展,但未与初始裂纹产生交汇;变形速率较小时,二次破裂位于侧壁靠近凹模圆角处;变形速率较大时,二次破裂位于侧壁靠近凸模圆角处。
[Abstract]:Taking the typical characteristic structure of automobile hot stamping workpiece, U-shaped beam as the research object, the high temperature fracture criterion of BR1500HS steel is embedded in the finite element model of hot stamping forming, and the effective prediction of high strength steel sheet fracture behavior at high temperature is realized. The effect of deformation rate on the initiation time, position and propagation direction of sheet metal fracture is revealed. The results show that with the increase of deformation rate, the initiation time is shortened, but the change of initiation position is not obvious, and the initiation crack is located on the lateral wall of the U-shaped beam. The crack propagates along the U-shaped beam longitudinally, followed by secondary rupture at the lateral wall of the other end. The crack also propagates along the U-shaped beam longitudinally, but does not intersect with the initial crack, and the deformation rate is small. The secondary rupture is located near the corner of the die, and when the deformation rate is high, the secondary rupture is near the corner of the die.
【作者单位】：湖北汽车工业学院材料学院;华中科技大学模具技术国家重点实验室;
【基金】：国家自然科学基金资助项目(51205116) 湖北省自然科学基金资助项目(2014CFB628) 湖北省高等学校优秀中青年科技创新团队计划项目(T201518) 汽车动力传动与电子控制湖北省重点实验室(湖北汽车工业学院)开放基金资助项目(ZDK1201601)
【分类号】：TG306

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