Effects of air on metallic sheet deformation by electromagnetic forming

2019 ◽  
Vol 103 (1-4) ◽  
pp. 311-324 ◽  
Author(s):  
Ning Liu ◽  
Zhipeng Lai ◽  
Quanliang Cao ◽  
Xiaotao Han ◽  
Yujie Huang ◽  
...  
2016 ◽  
Vol 26 (4) ◽  
pp. 1-4 ◽  
Author(s):  
Qi Xiong ◽  
Quanliang Cao ◽  
Xiaotao Han ◽  
Zhipeng Lai ◽  
Fangxiong Deng ◽  
...  

2021 ◽  
Author(s):  
Manoj Soni ◽  
Meraj Ahmed ◽  
Sanjay Kumar Panthi ◽  
Surendra Kumar ◽  
Khushwant Singh Gavel

Abstract Electromagnetic forming process is a high velocity forming technique which is widely used in automotive and aerospace sectors for forming and joining metallic sheet/tubes. The geometrical structure of compression coil have significant effect on the performance of the system in terms of current output and deformation of workpiece. The present work aims to analyse the effect of structural parameters of compression coil like cross-section of turns (X), pitch circular diameter (PCD) and effective turn (n) using both experimental and numerical simulation. A bitter compression coil of variable geometrical structure have been considered to see the effect of its parameters by deforming an AA6061 tube experimentally. Parameters like magnetic field, velocity, Lorentz force, displacement and stress are difficult to measure experimentally but have significant indication on performance of the coil in EMF. The trends of numerically predicated parameters find good agreement with experimental deformation value of tube. The Finite element analysis is carried out to correlate deformation results.The results indicate that n have higher significant in performance of compression coil as compared to X and PCD of coil.


2020 ◽  
Vol 11 (2) ◽  
pp. 329-347
Author(s):  
Zarak Khan ◽  
Mushtaq Khan ◽  
Syed Husain Imran Jaffery ◽  
Muhammad Younas ◽  
Kamran S. Afaq ◽  
...  

Abstract. Electromagnetic forming is a high-speed sheet metal forming technique to form metallic sheets by applying magnetic forces. In comparison to the conventional sheet metal forming process, electromagnetic forming is a process with an extremely high velocity and strain rate, which can be effectively used for the forming of certain difficult-to-form metals. During electromagnetic forming, it is important to recognise the effects of process parameters on the deformation and sheet thickness variation of the sheet metal. This research focuses on the development of a numerical model for aluminium alloy (AA6061-T6) to analyse the effects of three process parameters, namely voltage, sheet thickness and number turns of the coils, on the deformation and thickness variation of the sheet. A two-dimensional fully coupled finite-element (FE) model consisting of an electrical circuit, magnetic field and solid mechanics was developed and used to determine the effect of changing magnetic flux and system inductance on sheet deformation. Experiment validation of the results was performed on a 28 KJ electromagnetic forming system. The Taguchi orthogonal array approach was used for the design of experiments using the three input parameters (voltage, sheet thickness and number of turns of the coil). The maximum error between numerical and experimental values for sheet thickness variation was observed to be 4.9 %. Analysis of variance (ANOVA) was performed on the experimental results. Applied voltage and sheet thickness were the significant parameters, while the number of turns of the coil had an insignificant effect on sheet deformation. The contribution ratio of voltage and sheet thickness was 46.21 % and 45.12 % respectively. The sheet deformation from simulations was found to be in good agreement with the experimental results.


2021 ◽  
Vol 5 (2) ◽  
pp. 45
Author(s):  
Siddhant Prakash Goyal ◽  
Mohammadjavad Lashkari ◽  
Awab Elsayed ◽  
Marlon Hahn ◽  
A. Erman Tekkaya

Multiturn coils are required for manufacturing sheet metal parts with varying depths and special geometrical features using electromagnetic forming (EMF). Due to close coil turns, the physical phenomena of the proximity effect and Lorentz forces between the parallel coil windings are observed. This work attempts to investigate the mechanical consequences of these phenomena using numerical and experimental methods. A numerical model was developed in LS-DYNA. It was validated using experimental post-mortem strain and laser-based velocity measurements after and during the experiments, respectively. It was observed that the proximity effect in the parallel conductors led to current density localization at the closest or furthest ends of the conductor cross-section and high local curvature of the formed sheet. Further analysis of the forces between two coil windings explained the departure from the “inverse-distance” rule observed in the literature. Finally, some measures to prevent or reduce undesired coil deformation are provided.


1987 ◽  
Vol 109 (2) ◽  
pp. 388-391 ◽  
Author(s):  
E. M. Sparrow ◽  
M. A. Ansari

Measurements were made of the combined natural convection and radiation heat transfer from a horizontal finned tube situated in a vertical channel open at the top and bottom. In one set of experiments, both walls of the channel were heavily insulated, while in a second set of experiments, one of the insulated walls was replaced by an uninsulated metallic sheet. In general, the heat transfer coefficients were found to be lower with the metal wall in place, but only moderately. With the finned tube situated at the bottom of the channel, the differences in the heat transfer coefficients corresponding to the two types of walls were only a few percent. When the tube was positioned at the mid-height of the channel, larger differences were encountered, but in the practical range of Rayleigh numbers, the differences did not exceed 5 percent.


2021 ◽  
Vol 70 ◽  
pp. 140-151
Author(s):  
Quanliang Cao ◽  
Xian Li ◽  
Zhenhao Li ◽  
Limeng Du ◽  
Liangyu Xia ◽  
...  

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