Photoplastic investigation on sheet deformation in viscous pressure bulging

2008 ◽  
Author(s):  
Yan Liu ◽  
Zhongjin Wang
Keyword(s):  
Viscous Pressure ◽  
Viscous Pressure Bulging ◽  
Sheet Deformation

Viscous pressure bulging of aluminium alloy sheet at warm temperatures

2007 ◽  
Vol 21 (10) ◽  
pp. 1505-1511 ◽  
Author(s):  
Jianguang Liu ◽  
Qiucai Peng ◽  
Yan Liu ◽  
Zhongjin Wang
Keyword(s):  
Aluminium Alloy ◽  
Alloy Sheet ◽  
Viscous Pressure ◽  
Viscous Pressure Bulging

Effect of Loading Location of Viscous Medium on Sheet Deformation in Viscous Pressure Bulge (VPB) Test

2010 ◽  
Vol 154-155 ◽  
pp. 775-780
Author(s):  
Jian Guang Liu ◽  
Zhong Jin Wang ◽  
Qing Yuan Meng ◽  
Yu Long Zheng
Keyword(s):  
High Pressure ◽  
Sheet Metal ◽  
Deformation Behavior ◽  
Central Zone ◽  
Viscous Medium ◽  
Dome Height ◽  
Loading Mode ◽  
Viscous Pressure ◽  
Viscous Pressure Forming ◽  
Sheet Deformation

Viscous pressure forming (VPF) uses a highly viscous but flowable material as pressure-carrying medium (PCM). Due to the relative low flowability of viscous medium compared with fluid, nonuniform pressure distribution in viscous medium can be used to control and regulate the deformation sequence of the workpiece through controlling the loading mode of viscous medium. In the present study, viscous pressure bulge (VPB) tests with three kinds of loading location of viscous medium (central zone, corner zone and the whole deformation zone) are conducted and the influences of loading location of viscous medium on sheet deformation behavior are investigated via numerical simulations and experiments. It is found that changing the loading location of viscous medium can greatly affect the deformation behavior of sheet metal. When the viscous medium is injected from the die corner zone, a local high pressure formed at the corner zone of sheet metal and a higher limiting dome height and strains are obtained.

Effects of viscosity on viscous pressure bulging (VPB) of Al1060 sheet

2015 ◽  
Vol 86 (1-4) ◽  
pp. 215-225 ◽  
Author(s):  
Binxian Yuan ◽  
Wa Fang ◽  
Jiguang Li ◽  
Zhoude Qu ◽  
Yujun Cai ◽  
...  
Keyword(s):  
Viscous Pressure ◽  
Viscous Pressure Bulging

scholarly journals Cosmic Evolution of Viscous QCD Epoch in Causal Eckart Frame

Universe ◽  
2021 ◽  
Vol 7 (5) ◽  
pp. 112
Author(s):  
Eman Abdel Hakk ◽  
Abdel Nasser Tawfik ◽  
Afaf Nada ◽  
Hayam Yassin
Keyword(s):  
Energy Density ◽  
Energy Flow ◽  
Equations Of State ◽  
Temporal Evolution ◽  
Particle Diffusion ◽  
Cosmic Evolution ◽  
Bulk Viscous ◽  
Viscous Pressure ◽  
Bulk Viscous Pressure ◽  
Particle Current

It is conjectured that in cosmological applications the particle current is not modified but finite heat or energy flow. Therefore, comoving Eckart frame is a suitable choice, as it merely ceases the charge and particle diffusion and conserves charges and particles. The cosmic evolution of viscous hadron and parton epochs in casual and non-casual Eckart frame is analyzed. By proposing equations of state deduced from recent lattice QCD simulations including pressure p, energy density ρ, and temperature T, the Friedmann equations are solved. We introduce expressions for the temporal evolution of the Hubble parameter H˙, the cosmic energy density ρ˙, and the share η˙ and the bulk viscous coefficient ζ˙. We also suggest how the bulk viscous pressure Π could be related to H. We conclude that the relativistic theory of fluids, the Eckart frame, and the finite viscous coefficients play essential roles in the cosmic evolution, especially in the hadron and parton epochs.

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