Study on the three-dimensional tensile creep anisotropy of a hot-rolled Mg-0.9Mn-1.5Ce alloy sheet

Studies on electromagnetic impact welding between similar or dissimilar flat sheet metals using the flat one turn coil have been recently achieved. In this study, three dimensional electromagnetic-mechanical coupled numerical simulations are performed for the electromagnetic impact welding of aluminum alloy sheets with flat rectangular one turn coil. The deformation behavior during impact welding was examined. The effect of process parameters such as charge voltage, standoff distance and gap distance were investigated.

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Overall buckling analysis on different formed circular steel tubular columns under axial compression

MATEC Web of Conferences ◽

10.1051/matecconf/201927703017 ◽

2019 ◽

Vol 277 ◽

pp. 03017

Author(s):

Xi Feng Yan

Keyword(s):

Numerical Analysis ◽

Axial Compression ◽

Experimental Studies ◽

Three Dimensional ◽

Element Model ◽

Welded Steel ◽

Eurocode 3 ◽

Column Design ◽

Hot Rolled ◽

Overall Buckling

This paper presents a numerical finite element model (FEM) investigation on the overall buckling behaviour of hot-rolled (HR), submerged arc welded (SAW) and high-frequency welded (HFW) steel circular columns under axial compression. Three dimensional FEM of circular hollow sections were developed using shell elements considering material nonlinearities, geometric imperfections and residual stress. The established FEM was used to simulate experimental studies conducted by past researchers. Good agreement has been found between numerical analysis and past researchers results, which has validated the reasonability of the FEM to carry out further investigation. Based on the validated FEM, numerical analysis incorporating 180 numerical generated HR, SAW and HFW steel circular columns with various section sizes and slenderness were carried out. The numerical analysis results were compared with the existing column design curves in Chinese, European and American codes. The numerical results showed that the design resistances for hot-rolled and welded steel circular columns calculated based on design curve a in both GB 50017-2003 and Eurocode 3 and the design formula in ANSI/AISC 360-2016 should be accepted. In addition, to further improve the design efficiency, new column design curves for hot-rolled and welded steel circular columns were recommended based on the expressions in GB 50017-2003 and Eurocode 3.

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Recrystallization Microstructure Prediction of a Hot-Rolled AZ31 Magnesium Alloy Sheet by Using the Cellular Automata Method

Mathematical Problems in Engineering ◽

10.1155/2019/1484098 ◽

2019 ◽

Vol 2019 ◽

pp. 1-15

Author(s):

Ming Chen ◽

Xiaodong Hu ◽

Hongyang Zhao ◽

Dongying Ju

Keyword(s):

Flow Stress ◽

Magnesium Alloy ◽

Cellular Automata ◽

Process Analysis ◽

Rolling Process ◽

Alloy Sheet ◽

Az31 Magnesium Alloy ◽

Rolled Sheet ◽

Element Analysis ◽

Hot Rolled

A large reduction rolling process was used to obtain complete dynamic recrystallization (DRX) microstructures with fine recrystallization grains. Based on the hyperbolic sinusoidal equation that included an Arrhenius term, a constitutive model of flow stress was established for the unidirectional solidification sheet of AZ31 magnesium alloy. Furthermore, discretized by the cellular automata (CA) method, a real-time nucleation equation coupled flow stress was developed for the numerical simulation of the microstructural evolution during DRX. The stress and strain results of finite element analysis were inducted to CA simulation to bridge the macroscopic rolling process analysis with the microscopic DRX activities. Considering that the nucleation of recrystallization may occur at the grain and R-grain boundary, the DRX processes under different deformation conditions were simulated. The evolution of microstructure, percentages of DRX, and sizes of recrystallization grains were discussed in detail. Results of DRX simulation were compared with those from electron backscatter diffraction analysis, and the simulated microstructure was in good agreement with the actual pattern obtained using experiment analysis. The simulation technique provides a flexible way for predicting the morphological variations of DRX microstructure accompanied with plastic deformation on a hot-rolled sheet.

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