Ductile Fracture by Central Bursts in Drawn 2011 Aluminium Wire
Ductile Fracture by Central Bursts in Drawn 2011 Aluminium Wire
复制标题
2011 年拉制铝线材中心破裂导致的延性断裂
DOI：
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发表时间：
2005
期刊：
影响因子：
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通讯作者：
P. Phelan
中科院分区：
文献类型：
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作者：
P. McAllen;P. Phelan
本文报道了应用数值技术预测拉丝过程中中心爆裂缺陷的产生和扩展。通过用户编写的子程序，将合适的失效模型开发和实施到商业有限元代码中，成功地分析了2011年铝合金线材中心爆裂引起的韧性断裂。在验证数值模型，拉拔力，模具压力和发生中心爆裂缺陷已与先前公布的实验数据进行了比较。从数值模型的结果表明，一个“鼻子形状”曲线划分的安全和不安全区的成功拉丝。因此，当压下率小于临界值时，无论使用何种模具角度，都不会发生中心爆裂。当中心破裂确实发生时，发现有效应变沿金属丝表面沿着周期性变化。这些振荡与中心爆裂缺陷的发生相对应，并导致导丝最终直径的变化。金属丝最终直径的这些变化被认为是被称为“竹痕”的外部缺陷的代表，其通常是金属丝内中心爆裂缺陷的外部指示。
This paper reports on the application of numerical techniques to predict the initiation and propagation of central burst defects in the wire drawing process. The development and implementation of a suitable failure model into a commercial finite element code, via a user written subroutine, has enabled the occurrence of ductile fracture by central bursting in 2011 Aluminium alloy wire to be successfully analysed. In validating the numerical model, the drawing force, die pressure and occurrence of central burst defects has been compared with previously published experimental data. Results from the numerical model suggest that a ‘nose shape’ curve divides the safe and unsafe zones for the successful drawing of the wire. It follows that no central bursts are expected to occur, regardless of the die angle used, when the reduction ratio is less than a critical value. When central bursts did occur, the effective strain was found to vary periodically along the surface of the wire. These oscillations corresponded with the occurrence of central burst defects and resulted in variations in the final diameter of the wire. These variations in the final diameter of the wire are thought to be representative of an external defect known as ‘bamboo markings’, which are often an external indication of central burst defects within the wire.