摘要
文章将考虑静水应力、最大主应力及应变历史对材料损伤影响的Brozzo断裂准则模型,用于闭挤式精冲的断裂预测。分析了变形区材料的应力、应变状态对材料断裂损伤的影响,并通过DEFORM-2D有限元软件的模拟及物理试验进行验证。研究表明,Brozzo断裂准则能比较精确地模拟闭挤式精冲过程,模拟结果与试验误差在6%以内;主、副凹模闭合时,变形区材料所受的压应力越大,越有利于抑制裂纹的产生和扩展;精冲过程中,凸模刃口附近材料的压应力大于主凹模刃口附近材料,裂纹首先出现在主凹模刃口处,材料开始产生裂纹时的有效应变,随压应力的增加而增大。
The Brozzo Fracture Criterion model considering the influence of hydrostatic stress, maximum principle stress and strain history on material fracture was applied to predict the fracture of closed extruding fine-blanking. The influence of the stress and strain state of deforming area on material fracture damage was analyzed, and validated through simulation hy DEFORM-2D finite element software and physical experiments. The research shows that Brozzo Fracture Criterion can simulate the closed extruding fine-blanking process accurately with the experimental error between simulation and actual experiment within 6 % ; when the main and sub dies close, more larger compressive stress at the deformation area is more beneficial to prevent the appearing and spreading of fracture; during the fine-blanking process, fracture will firstly appear near the main die edge, where the compressive stress of the material is less than that around punch edge; and that the effective strain when fracture appears increases with the increase of compressive stress.
出处
《塑性工程学报》
CAS
CSCD
北大核心
2011年第1期67-71,共5页
Journal of Plasticity Engineering
基金
重庆市科技攻关计划资助项目(CSTC2010AC3086)
关键词
精冲
韧性断裂
静水应力
精密成形
冲压
fine-blanking
ductile fracture
hydrostatic stress
precision forming
blanking
