[1]徐贵娥,孙正华,方峰,等.拉丝过程中的缺陷模拟及其在拉拔工艺优化中的应用[J].东南大学学报(自然科学版),2005,35(3):409-414.[doi:10.3969/j.issn.1001-0505.2005.03.019]
 Xu Guie,Sun Zhenghua,Fang Feng,et al.Modeling of the central flaw in wire drawing and its application to processing optimization[J].Journal of Southeast University (Natural Science Edition),2005,35(3):409-414.[doi:10.3969/j.issn.1001-0505.2005.03.019]
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拉丝过程中的缺陷模拟及其在拉拔工艺优化中的应用()
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《东南大学学报(自然科学版)》[ISSN:1001-0505/CN:32-1178/N]

卷:
35
期数:
2005年第3期
页码:
409-414
栏目:
材料科学与工程
出版日期:
2005-05-20

文章信息/Info

Title:
Modeling of the central flaw in wire drawing and its application to processing optimization
作者:
徐贵娥1 孙正华1 方峰2 李兆霞1 蒋建清2
1 东南大学土木工程学院, 南京 210096; 2 东南大学材料科学与工程系, 南京 210096
Author(s):
Xu Gui’e1 Sun Zhenghua1 Fang Feng2 Li Zhaoxia1 Jiang Jianqing2
1 College of Civil Engineering, Southeast University, Nanjing 210096, China
2 Department of Material Science and Engineering, Southeast University, Nanjing 210096, China
关键词:
拉拔 钢丝 人字形裂纹 临界尺寸 J积分值
Keywords:
drawing steel wire central flaw critical size J-integral value
分类号:
TG256
DOI:
10.3969/j.issn.1001-0505.2005.03.019
摘要:
模拟了无缺陷时盘条在高形变区的应力场分布,说明了芯部人字形裂纹形成的机理.然后针对芯部圆盘状裂纹提出轴对称计算模型,基于此计算模型研究模具顶角、摩擦系数等工艺参数对形变区内裂纹尖端应力场分布的影响,得出随着拉丝模具顶角的增大和摩擦系数的减小,裂纹尖端应力集中区域与拉丝轴之间的夹角变小,即形成笔尖状断口的斜角变大,笔尖变得更细长.最后定量研究了模具顶角、摩擦系数、裂纹尺寸对J积分的影响.结果表明:随着裂纹尺寸的增加、模具顶角的增大和摩擦系数的增大,J积分值随之增大; 在摩擦系数为0.1时,对于相同尺寸的裂纹,J积分值随着模具顶角的减小而减小,当达到模具顶角8°后,J积分值变化较小,趋于一定值.研究结果应用于拉丝工艺优化,为进一步改进工艺提出了指导性建议.
Abstract:
Mechanism of central flaw generation is illuminated by modeling the stress distribution in heavy deformation zone of a wire without defect. An axisymmetrical numerical model is proposed on the basis of the assumption of the central axisymmetrical flaw, and the effects of parameters(die angle and friction coefficient etc.)on the stress field near the crack tip during the wire deformation are analyzed with the developed axisymmetrical finite element model. It can be concluded that the angle between the stress singularity zone near the crack tip and steel central-line decreases(i.e. a greater gradient of the nibbed pencil fracture and a longer neb)with increasing die angle and decreasing friction coefficient. The quantitative analysis of the effects of die angle, friction coefficient and flaw size on J-integral value is carried out by the calculation with ANSYS. It is shown that: J-integral value increases with increasing die angle, friction coefficient and the initial dimension of the flaw. When friction coefficient equals 0.1, J-integral value round the crack tip with the same flaw decreases with decreasing die angle. J-integral value changes slightly and tends to be a constant value when the angle reaches to 8°. The calculated results are then applied to improve the optimization of the technology for wire drawing.

参考文献/References:

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备注/Memo

备注/Memo:
基金项目: 江苏省自然科学基金重点资助项目(BK2001215)、国家高技术研究发展计划(863计划)资助项目(2003AA331030)、江苏省科技攻关资助项目(BE2003027).
作者简介: 徐贵娥(1979—),女,硕士生; 李兆霞(联系人),女,博士,教授,博士生导师,zhxli@seu.edu.cn.
更新日期/Last Update: 2005-05-20