板料冲压成形破坏判断准则的研究进展

Review on Fracture Criterion of Sheet Metal Forming

分析板料冲压成形中有无明显集中缩颈的韧性破裂、剪切破裂判断准则的研究现状。比较成形极限图以及韧性破裂准则在判断板料破坏中各自的优缺点。针对当前有限元分析软件中的破坏准则用于判断板料局部小特征弯曲强化的成形极限或是先进高强钢板在缩颈前产生剪切破裂等问题所存在的局限性,综述上述特殊问题的研究进展。提出建立沿横、纵两个方向拉伸弯曲下的极限判据对于预测板料局部小特征弯曲的成形极限将更有普遍意义。同时有必要进一步研究先进高强钢板成形的剪切破裂机理,并建立可以有效预测先进高强钢板剪切破裂的有限元模拟失效判据。研究板料成形的上述破坏问题及其判断准则,对于丰富与发展塑性成形理论和指导实际生产具有重要的理论意义和工程应用价值。

Criterions of ductile fracture（with or without obvious localized necking） and shear fracture of sheet metal forming are analyzed respectively.Advantages and disadvantages of forming limit diagrams and ductile fracture criterions are also compared.The research progress on bending-enhanced forming limit with tight features and shear fracture occurring before necking of advanced high-strength steels（AHSS） are mainly analyzed.These two problems can＇t be predicted exactly by the conventional failure criterions embedded in finite element analysis software.The paper presents that it will be more universally significant to predict bending-enhanced forming limit with tight features when bending is assumed along the transverse longitudinal principle loading direction respectively.And it is also necessary to study the shear fracture mechanism of AHSS to develop a failure criterion that can be used in finite element simulation.It will help to develop the plastic forming theory and guide the engineering applications.