Identification of Deformation Mechanisms Responsible for Failure in Incremental Forming using a Damage Based Fracture Model
Identification of Deformation Mechanisms Responsible for Failure in Incremental Forming using a Damage Based Fracture Model
复制标题
使用基于损伤的断裂模型识别导致渐进成形失败的变形机制
DOI：
10.1063/1.3623646
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
T. Belytschko
中科院分区：
文献类型：
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作者：
R. Malhotra;L. Xue;Jian Cao;T. Belytschko
单点增量成形 (SPIF) 最近因其更高的成形性和更大的工艺灵活性而引起了人们的极大兴趣。然而，SPIF 中涉及的复杂变形机制阻碍了对导致失效的主要机制的最终确定。这项工作使用显式有限元分析和基于损伤的断裂模型成功地预测了 SPIF 中的成形力和失效的发生，其中失效包络线取决于静水压力和洛德角。此外，结果表明，全厚度剪切是 SPIF 失效的主要原因。还进行了模拟，以使用 SPIF 和传统的冲头和模具形成相同的部件，并对两种工艺中的主要失效机制进行了比较。此外，研究表明，减少工具片摩擦可以延迟 SPIF 的断裂，并且还讨论了这种效应背后的机制。
Single Point Incremental forming (SPIF) has generated significant interest recently due to its increased formability and greater process flexibility. However, the complicated deformation mechanisms involved in SPIF have prevented conclusive identification of the primary mechanisms responsible for failure. This work successfully predicts the forming forces and occurrence of failure in SPIF using explicit FEA with a damage based fracture model in which failure envelope depends on the hydrostatic pressure and the Lode angle. Furthermore it is shown that through‐the‐thickness shear is primarily responsible for failure in SPIF. Simulations are also performed to form the same component using SPIF and using a conventional punch and die, and a comparison is made between the dominant mechanisms of failure in the two processes. Furthermore, it is shown that reduction of tool‐sheet friction can delay fracture in SPIF and the mechanism behind this effect is discussed as well.