Abstract Cross wedge rolling (CWR) is an innovative roll forming process, used widely in the transportation industry. It has high production efficiency, consistent quality and efficient material usage. However, the continual occurrence of crack formation in the centre of the workpiece is a critical problem excluding the CWR technique from more safety-critical applications, in particular, aerospace components. The mechanisms of central fracture formation are still unclear because of a combination of complicated stress and strain states at various stages of CWR. Thus, the aim of this study is to understand the stress/strain distribution and evolution during the CWR process and identify the key variables which determine central crack formation. A comprehensive investigation was then conducted to simulate 27 experimental cases. The stress and strain distributions in the workpiece were evaluated by finite element analysis. Various damage models from literature were applied and compared. A new fracture criterion was proposed, which was able to successfully determine the central crack formation in all 27 experimental cases. This criterion can be applied in CWR tool and process design, and the enhanced understanding may enable the adoption of CWR by the aerospace industry.

中文翻译：

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楔横轧中心裂纹形成的研究

摘要 楔横轧（CWR）是一种创新的辊轧成型工艺，广泛应用于交通运输行业。生产效率高，质量稳定，材料利用率高。然而，在工件中心持续出现裂纹是一个关键问题，将 CWR 技术排除在更安全的关键应用之外，特别是航空航天部件。由于 CWR 不同阶段复杂的应力和应变状态的组合，中心裂缝的形成机制仍不清楚。因此，本研究的目的是了解 CWR 过程中的应力/应变分布和演变，并确定决定中心裂纹形成的关键变量。然后进行了全面调查以模拟 27 个实验案例。通过有限元分析评估工件中的应力和应变分布。应用和比较了文献中的各种损伤模型。提出了一种新的断裂准则，该准则能够成功确定所有 27 个实验案例中的中心裂纹形成。该标准可应用于 CWR 工具和工艺设计，增强的理解可以使航空航天工业采用 CWR。