Identifying elasto-plastic damage coupling model of laser-welded aluminum alloy by virtual field method and digital image correlation. (September 2020)

• Record Type: Journal Article
• Authors: Jiang, Hao; Lei, Zhenkun; Bai, Ruixiang; Wu, Wen; Liu, Da; Guo, Zhenfei; Yan, Cheng; Dong, Honggang; Li, Mingqiang
• Is Part Of: Optics & laser technology. Volume 129(2020)
• Publication Date: 2020-09
• Subjects: Laser welding -- Inversion -- Elasto-plastic damage coupling constitutive -- Return mapping iterative algorithm -- Virtual field method -- Digital image correlation; Optics -- Periodicals; Lasers -- Periodicals; Electronic journals; 621.366
• DOI: 10.1016/j.optlastec.2020.106268
• Languages: English
• ISSNs: 0030-3992

Abstract

Highlights: Non-uniform strain fields of laser weld are measured by 3D-DIC. Plastic and damage parameters of laser weld are identified by nonlinear VFM. A new return mapping stress reconstruction is proposed for plastic-damage model. Both plastic and damage properties of the weld are clearly weakened. Abstract: The local high temperature of laser welding affects the mechanical damage properties of aluminum alloy. The full-field strain near the weld of the laser-welded aluminum alloy 6061 under uniaxial tension was obtained using digital image correlation. An iterative stress increment method for the isotropically hardened elasto-plastic damage coupling constitutive model is proposed herein based on the combination of a return mapping scheme and the nonlinear virtual field method. The elasto-plastic damage coupling constitutive parameters and its corresponding stress–strain relationship in each subzone around the weld are established. The results show that the plastic strain accumulating in the heat-affected zone is the fastest, where the damage initiation occurs earlier, and the damage evolution speed is faster than that other zones.