A method for determining material's equivalent stress-strain curve with any axisymmetric notched tensile specimens without Bridgman correction

Autor: Jianying He, Zhiliang Zhang, Xiaobo Ren, Shengwen Tu
Rok vydání: 2018
Předmět:
Zdroj: International Journal of Mechanical Sciences
ISSN: 0020-7403
DOI: 10.1016/j.ijmecsci.2017.12.012
Popis: Large deformation analyses of problems such as plastic forming, ductile fracture with finite element method need a full range of material's equivalent stress-strain curve or flow stress-strain curve. The equivalent stress-strain curve determined from the smooth round bar specimen should be corrected after diffuse necking, since tri-axial stress state occurs in the neck. The well-known Bridgman correction method is a candidate, however, it is not accurate as the strain increases. Furthermore, it is impossible to measure the equivalent stress-strain curve of each individual material zone in a weldment with cross weld tensile tests. To cope with these challenges, a correction function and an associated test procedure are proposed in this study. With the proposed procedure, the true stress-strain curve from any axisymmetric notched tensile specimen can be converted to the material's equivalent stress-strain curve accurately and no Bridgman correction is needed. The proposed procedure can be applied to both perfectly plastic and strain hardening materials. The equivalent stress-strain curve of each individual material zone in a weldment can also be measured with the proposed procedure. This is a submitted manuscript of an article published by Elsevier Ltd in International Journal of Mechanical Sciences, 7 December 2017.
Databáze: OpenAIRE
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