1. Assessment of finite element analyses of load mode (bending vs. tension) effects for mitigation of judgment on pop-ins caused by splits
- Author
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Shuji Aihara, Sohei Kanna, Tetsuya Tagawa, Yoichi Yamashita, Shigetoshi Kyono, Fumiyoshi Minami, Tomoya Kawabata, Yoichi Kayamori, Yasuhito Imai, Tsuyoshi Sakurai, Houichi Kitano, Yoshiki Mikami, Yukito Hagihara, Mitsuru Ohata, and Tomoyuki Tonan more...
- Subjects
Materials science ,genetic structures ,business.industry ,Mechanical Engineering ,Drop (liquid) ,0211 other engineering and technologies ,02 engineering and technology ,Welding ,Structural engineering ,Stress distribution ,Finite element method ,law.invention ,020303 mechanical engineering & transports ,Brittleness ,Fracture toughness ,0203 mechanical engineering ,Brittle crack ,Mechanics of Materials ,law ,Ultimate tensile strength ,General Materials Science ,business ,021101 geological & geomatics engineering - Abstract
During a fracture toughness test on a welded joint, a pop-in accompanied by a load drop may occur prior to final rupture. The currently used standards for conditions to determine whether pop-ins are insignificant vary, and are not prescribed based on adequate physical grounds. Moreover, these standards can be too severe in considering the occurrence of pop-ins as equivalent to a fatal rupture in welded structures. Research to formulate reasonable conditions to assess pop-ins is important to determine whether it is necessary to remake or repair the relevant welded structure. This study reports fracture toughness tests on specimens with pop-ins caused by brittle cracks featuring arrest behavior. The results were simulated through finite element analysis by using a nodal release method, which was implemented when a pop-in occurred owing to split formation, to determine whether the pop-in was significant. From analytical results based on a load mode featuring bending and tension, it was found that the crack opening stress distribution under the bending mode at a load drop of 8% or less was larger than or almost equal to that under the tensile mode. Therefore, if the opening of a brittle crack is arrested during three-point bending fracture toughness tests, it would also be arrested in the welded structures under tensile load. In other words, the results showed that such a pop-in could be regarded as insignificant. more...
- Published
- 2019
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