Fracture Toughness Calculation Method Amendment of the Dissimilar Steel Welded Joint Based on 3D XFEM

• Main Authors: Yuwen Qian, Jianping Zhao
• Format: Article
• Language: English
• Published: MDPI AG 2019-04-01
• Series: Metals
• Subjects: undermatched; integrity identification; XFEM; fracture toughness calculation method
• Online Access: https://www.mdpi.com/2075-4701/9/5/509

The dissimilar steel welded joint is divided into three pieces, parent material&#8722;weld<br />metal&#8722;parent material, by the integrity identification of BS7910-2013. In reality, the undermatched<br />welded joint geometry is dierent: parent material&#8722;heat aected zone (HAZ)&#8722;fusion line&#8722;weld metal.<br />A combination of the CF62 (parent material) and E316L (welding rod) was the example undermatched<br />welded joint, whose geometry was divided into four pieces to investigate the fracture toughness of the<br />joint by experiments and the extended finite element method (XFEM) calculation. The experimental<br />results were used to change the fracture toughness of the undermatched welded joint, and the XFEM<br />results were used to amend the fracture toughness calculation method with a new definition of the<br />crack length. The research results show that the amendment of the undermatched welded joint<br />geometry expresses more accuracy of the fracture toughness of the joint. The XFEM models were<br />verified as valid by the experiment. The amendment of the fracture toughness calculation method<br />expresses a better fit by the new definition of the crack length, in accordance with the crack route<br />simulated by the XFEM. The results after the amendment coincide with the reality in engineering.