Open AccessA method of constitutive experiment for accurate description of tube performance under rotary-draw bending
Author(s) -
Yu Zhu,
R. Chen,
Y. Wang,
Wenbin Tu,
Y. L. Liu
Publication year - 2020
Publication title -
iop conference series. materials science and engineering
Language(s) - English
Resource type - Journals
eISSN - 1757-899X
pISSN - 1757-8981
DOI - 10.1088/1757-899x/770/1/012073
Subject(s) - bending , tube (container) , constitutive equation , materials science , stress (linguistics) , structural engineering , displacement (psychology) , deformation (meteorology) , beam (structure) , mechanics , composite material , finite element method , engineering , physics , psychology , linguistics , philosophy , psychotherapist
Establishing accurate constitutive relations is an important prerequisite for improving the springback prediction accuracy of rotary-draw bending of tubes. In this paper, the stress loading paths are studied for rectangular tube and composite circular tube in rotary-draw bending processes. It is found that there is reverse loading with tangential/circumferential stress for both the rectangular tube and the base/covered tube of composite circular tube. And the reverse loading is in the plastic deformation range. Two constitutive experimental schemes are designed according to the above research results: (1) The constitutive experiment is designed according to the variation of stress peak points of the tube with the bending process and the yield state of the material. The calculation method of the loading force F is given, too. (2) The displacement of the beam of the tensile tester is determined according to the corresponding strain during stress fluctuations, and an example is given to illustrate how the displacement of the beam is calculated according to the strain corresponding to each trajectory point. The calculation formula of the beam displacement during repeated loading, unloading and reverse loading is developed, too.