On the bending angle of aluminum-copper two-layer sheets in laser forming process

2021 ◽  
Vol 142 ◽  
pp. 107233
Author(s):  
Reza Masoudi Nejad ◽  
Zohreh Sadat Hoseini Shojaati ◽  
Greg Wheatley ◽  
Danial Ghahremani Moghadam
2006 ◽  
Vol 129 (6) ◽  
pp. 1035-1044 ◽  
Author(s):  
A. J. Birnbaum ◽  
P. Cheng ◽  
Y. L. Yao

Although considerable effort has gone into characterizing the laser forming process in terms of process parameters and conditions, there has been little emphasis on the effects of the mechanical and thermal constraints introduced by the clamping method utilized for a desired application. This research suggests means for investigating and predicting the resulting geometry of a specimen due to laser operation in close proximity to an array of imposed thermo-mechanical constraints for both the single and multiple scan cases; specifically, the resulting average bending angle as well as bending angle variations throughout the part. This is accomplished by initially only considering these effects on the thermal field. Conclusions are then drawn about the nature of the mechanical effects. These conclusions are validated through numerical simulation as well as physical experimentation. An analytical solution of the thermal problem is also presented for further validation of the temperature field as a constrained edge is approached.


Author(s):  
Amir H Roohi ◽  
H Moslemi Naeini ◽  
M Hoseinpour Gollo

Laser forming, which is categorized as a thermal forming process, is used in forming and bending of metallic and non-metallic sheets. Laser beam irradiation causes a localized temperature increase and a localized mechanical strength decrease. In this article, the effects of four process parameters, comprising laser power, scan velocity, the number of scan passes, and sheet thickness, on laser forming of Al6061-T6 sheets are studied. A design of experiment, including response surface methodology, is carried out to limit the experimental runs and costs and to identify the parameter effects on the bending angle of the sheet. Experiment results show that bending angle increases due to the decrease of scan velocity and sheet thickness. In addition, laser power and number of scan passes have a direct relation with a final sheet forming.


Author(s):  
Paramasivan Kalvettukaran ◽  
Sandip Das ◽  
Sundar Marimuthu ◽  
Dipten Misra

The laser bending process, also called the laser forming process, consists of irradiating the surface of a sheet or a plate by means of a moving laser beam with a predefined scanning strategy to generate the desired shape through thermally induced residual stress. This chapter presents the mechanisms of a laser bending process and the technological aspects concerning laser v-bending of rectangular AISI 304 plates for full plates and plates with a central cutout at its middle to highlight the process fundamentals and how processing affects the final bending angle of the workpieces. Laser bending involving plates with a cutout will have numerous applications for car bodies, such as front and rear panels where bending is required to be performed on panels with cutout geometries. To investigate the effects of shape and size of the cutout on temperature distribution, stress distribution, and final bending angle, different shapes such as circular, ellipse, rectangular, and square, as well as different dimensions of cutouts have been chosen.


Author(s):  
Esmaeil Ghadiri Zahrani ◽  
Abdolali Marasi

The existence of various variables in the laser forming process brings about the implementation of two important issues of modeling and optimization to more precisely predict bending angle so as to achieve desirable conditions. In this paper, the effect of independent process parameters such as laser power, beam diameter, scan speed, sheet thickness and also the heating position on the resulted bending angle from the sheet free edge was investigated through experimentation. The results indicate different influence of parameters on the angle. Also, using response surface methodology and after conducting analysis of variance, an efficient second-order mathematical model was fit to bending angle. Consequently, with the aim of making bending angle robust in relation to possible parametric fluctuations in the process, a simultaneous optimization was carried out by use of propagation of error approach and optimal parametric combination to reach the maximum value of the angle.


2010 ◽  
Vol 663-665 ◽  
pp. 947-951
Author(s):  
Jing Zhou ◽  
Hong Shen

Laser forming process analyzed under thermo-elasto-plastic finite element method can better understand the forming mechanism. However, it is very time consuming. This paper introduced the prediction of the deformation in laser forming based on the theory of inherent strain by finite element method (FEM). The relations between inherent strains and laser forming parameters based on some experimental curves and the thermo-elasto-plastic analysis can be determined, in which the inherent strains are assumed to be distributed in a rectangle shape. This method is much more convenient because only elastic analysis is involved. The effectiveness of the proposed method is demonstrated through the comparison with the experimental data.


2002 ◽  
Vol 124 (2) ◽  
pp. 379-388 ◽  
Author(s):  
Jin Cheng ◽  
Y. Lawrence Yao

Laser forming of steel is a hot forming process with high heating and cooling rate, during which strain hardening, dynamic recrystallization, and phase transformation take place. Numerical models considering strain rate and temperature effects only usually give unsatisfactory results when applied to multiscan laser forming operations. This is mainly due to the inadequate constitutive models employed to describe the hot flow behavior. In this work, this limitation is overcome by considering the effects of microstructure change on the flow stress in laser forming processes of low carbon steel. The incorporation of such flow stress models with thermal mechanical FEM simulation increases numerical model accuracy in predicting geometry change and mechanical properties.


2008 ◽  
Vol 375-376 ◽  
pp. 333-337
Author(s):  
Li Jun Yang ◽  
Yang Wang

Laser forming of metal sheet is a forming technology of sheet without a die that the sheet is deformed by internal thermal stress induced by partially irradiation of a laser beam. In this paper, the bending behavior of common stainless steel 1Cr18Ni9 sheet is studied after being irradiated by straight line with a Nd:YAG pulsed laser beam. The aim of the investigation is to find out the relationship of the physical behaviors of heat affected zone (HAZ) with the pulse parameters of the laser. Through the analysis of the fundamental theory of pulsed laser affected, this paper shows the affected characteristics of metal sheet with pulsed laser forming. The results show that the microstructure of HAZ of pulsed laser scanned is layered, and the micro-hardness is improved than that in matrix. The microstructures show that the deformed grain structure is inhomogeneous, that caused the grain sizes and grain orientations in HAZ to become different. By qualitative analysis of experimental result, the conclusion obtained may provide basis for theoretical investigation and possible industrial application of laser forming process in the future.


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