Ductile failure of flat plates containing two through-wall cracks: Experimental investigation and numerical modeling. (June 2021)

• Record Type: Journal Article
• Authors: Zhang, Xue-Wei; Wen, Jian-Feng; Wang, Tao; Zhang, Xian-Cheng; Tu, Shan-Tung
• Is Part Of: International journal of pressure vessels and piping. Volume 191(2021)
• Publication Date: 2021-06
• Subjects: Ductile failure -- Ductility exhaustion -- Crack interaction -- Multiple cracks -- Finite element analysis; Pressure vessels -- Periodicals; Pipe -- Periodicals; Récipients sous pression -- Périodiques; Tuyaux -- Périodiques; Pipe; Pressure vessels; Periodicals; 681.76041
• DOI: 10.1016/j.ijpvp.2021.104377
• Languages: English
• ISSNs: 0308-0161

Abstract

Abstract: Multiple cracks are frequently detected in structural components and should be assessed aimed to judge whether they can be treated as individual cracks or be combined to a larger crack. To study the ductile failure and crack interaction behavior, tensile tests using flat plates with two through-wall cracks were conducted, and 3D digital image correlation method (3D-DIC) was applied to acquire the displacement and full-field strain measurement. A damage evolution model integrated with a non-monotonic fracture strain locus was implemented to model the ductile fracture and crack interaction. Simulation results including load-displacement curves and predicted crack coalescence results fit well to the experiment data. Effects of mesh size and cut-off value of stress on the simulation results were investigated to ensure the accuracy of finite element analysis. The findings show that FE predictions using non-monotonic fracture strain locus are not only superior to those using monotonic ones, but also more accurate than alignment and combination rules in fitness-for-service codes. Highlights: A 3D-DIC method was applied to tests on crack interaction, growth and coalescence. Evaluation criteria in the FFS codes cannot well predict whether cracks coalesce. FE analysis with simple damage model reproduces the fracture process in all tests. Predictions with non-monotonic fracture locus are superior to monotonic ones.