Abstract
Experimental and theoretical studies are combined to investigate the phenomenon of macroscopic plastic deformation localization in metallic tensile specimens of AL6061, HSLA350 and Q235. The longitudinal strain and cross-section reduction of the specimens at different instant during testing are estimated through the measurement technique of three dimensional digital image correlation (3D-DIC). The Ling weighted-average method referred as WAM is used to compare the true stress-strain relation obtained from the experiment. A new mathematical model is suggested to estimate the localization zone length, which is a crucial parameter that can be used to anticipate the behaviour of metals past the peak load. The effect of material property on the necking zone length is examined. The experimental results show that the axial strain within the necking zone is non-uniform. It is also found that the WAM can precisely derive the true stress of steels Q235 and HSLA350 but not AL6061. The localization zone length of the round specimens Q235, HSLA350, and AL6061 equals six, five, and four times their initial diameter, respectively. Materials with a higher fracture strain ratio to the ultimate strain have a shorter necking zone length. This work provides insights into the physical mechanism of macroscopic plastic deformation localization.
Highlights
As an essential failure mechanism, plastic strain localization widely exists in a variety of engineering materials such as soil [1], rock [2], concrete [3, 4], and metal alloys [5, 6]
The ability to characterize strain localization as a precursor to final material failure is important for engineering applications of, e.g., metallic materials
The Ling weighted-average method referred as WAM is used to compare the true stress-strain relation obtained from the experiment
Summary
As an essential failure mechanism, plastic strain localization widely exists in a variety of engineering materials such as soil [1], rock [2], concrete [3, 4], and metal alloys [5, 6]. The ability to characterize strain localization as a precursor to final material failure is important for engineering applications of, e.g., metallic materials. There are three frequent forms of macroscopic inelastic deformation: (1) Lüders bands [7] which occur in some metals as a plateau past the yield stress for a small percent of strain until strain hardening resumes; (2) necking [8] which is a precursor to fracture; and (3) Portevin-Le Châtelier effect [9] which represents a typical plastic instability in many metallic alloys.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
