An analytical model for bending angle in metal/ceramic bilayer system of laser forming

2008 ◽  
Vol 104 (11) ◽  
pp. 113531
Author(s):  
Hong Shen ◽  
Zhenqiang Yao ◽  
Jun Hu
Keyword(s):  
Analytical Model ◽  
Laser Forming ◽  
Bending Angle ◽  
Bilayer System ◽  
Metal Ceramic

Analysis and Prediction of the In-Plane Deformation in Laser Thermal Adjustment

2012 ◽  
Vol 134 (4) ◽  
Author(s):  
Hong Shen ◽  
Jun Hu ◽  
Zhenqiang Yao
Keyword(s):  
Analytical Model ◽  
High Precision ◽  
Laser Processing ◽  
Plane Deformation ◽  
Experimental Results ◽  
Laser Forming ◽  
Bending Angle ◽  
Heating Stage ◽  
Plane Bending ◽  
Bending Angles

Laser thermal adjustment as an application of laser forming in microsystems has received considerable attentions in recent years. This process is a noncontact and high precision forming method. The traditional mechanical microforming technologies for the adjustment step used in microsystem assembly are often limited in their accuracy and are also time consuming. This paper presents an analytical model for describing the in-plane deformation of actuators during laser thermal adjustment. A formula for calculating the in-plane bending angle of the actuator generated by the laser processing is derived. The proposed analytical model is demonstrated by the comparison of the predicted bending angles with the numerical and experimental results. Finally, a formula to predict the possible buckling of the actuator during the laser processing is also developed, from which one can design the opening of the actuator in order to avoid the buckling of the actuator during a heating stage of the process.

Effects of Clamping on the Laser Forming Process

2006 ◽  
Vol 129 (6) ◽  
pp. 1035-1044 ◽  
Author(s):  
A. J. Birnbaum ◽  
P. Cheng ◽  
Y. L. Yao
Keyword(s):  
Thermal Field ◽  
Laser Forming ◽  
Considerable Effort ◽  
Forming Process ◽  
Thermal Problem ◽  
Bending Angle ◽  
Mechanical Constraints ◽  
Thermal Constraints ◽  
Close Proximity ◽  
Multiple Scan

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.

Bending Deformation of Pure Titanium Plate in CO2 Laser Forming

2007 ◽  
Vol 329 ◽  
pp. 625-630 ◽  
Author(s):  
Koichi Okuda ◽  
Y. Sugie ◽  
Masayuki Nunobiki
Keyword(s):  
Co2 Laser ◽  
Laser Power ◽  
Pure Titanium ◽  
Laser Spot ◽  
Laser Forming ◽  
Titanium Plate ◽  
Bending Angle ◽  
Spot Diameter ◽  
Bending Deformation ◽  
Laser Spot Diameter

This study deals with behaviour of bending deformation in CO2 laser forming process of titanium. CO2 laser forming technique was applied for a pure titanium plate with thickness of 1 mm to aim the development of new bending process. The experiments of laser forming were carried out with a CO2 laser machine. The bending angle and the temperature of workpiece were examined under the condition of various laser power, feed speed and laser spot diameter. Based on the experimental results, it was found that the bending deformation behaved greatly depending on the laser power and the laser spot diameter. The bending angle increased with an increase in the laser power. The bending direction tended to change from the laser irradiation side to its opposite side when the large laser spot diameter was applied.

Fuzzy logic model for bending angle in laser forming

2006 ◽  
Vol 22 (8) ◽  
pp. 981-986 ◽  
Author(s):  
H. Shen ◽  
Y. J. Shi ◽  
Z. Q. Yao ◽  
J. Hu
Keyword(s):  
Fuzzy Logic ◽  
Logic Model ◽  
Laser Forming ◽  
Bending Angle ◽  
Fuzzy Logic Model

Experimental and Numerical Studies on Microscale Bending of Stainless Steel With Pulsed Laser

1999 ◽  
Vol 66 (3) ◽  
pp. 772-779 ◽  
Author(s):  
G. Chen ◽  
X. Xu ◽  
C. C. Poon ◽  
A. C. Tam
Keyword(s):  
Stainless Steel ◽  
High Temperature ◽  
Material Properties ◽  
Steel Specimen ◽  
Laser Forming ◽  
Element Analysis ◽  
Bending Angle ◽  
Thermal Residual Stresses ◽  
Property Data ◽  
External Forces

Laser forming or laser bending is a newly developed, flexible technique which modifies the curvature of sheet metal by thermal residual stresses instead of external forces. The process is influenced by many parameters such as laser parameters, material properties, and target dimensions. In this work, a pulsed Nd:YLF laser was used as the energy source. The laser beam was focused into a line shape irradiating on the stainless steel specimen to induce bending. The bending angle was measured at various processing conditions. A finite element analysis was performed with the use of a two-dimensional plane strain model to calculate the thermoelastoplastic deformation process. Experimental measurements and computational results were in good agreement. Numerical sensitivity studies were performed to evaluate the effects of the unavailable material property data at high temperature. It was found that both optical reflectivity and thermal expansion coefficient influenced the bending angle significantly, while other extrapolated material properties at high temperature yielded acceptable results.

Heating Position Planning in Laser Forming of Single Curved Shapes Based on Probability Convergence

2016 ◽  
Vol 138 (9) ◽  
Author(s):  
Hong Shen ◽  
Yutao Zheng ◽  
Han Wang ◽  
Zhenqiang Yao
Keyword(s):  
Experimental Data ◽  
Inverse Problem ◽  
Minimum Distance ◽  
Processing Time ◽  
Probability Function ◽  
Laser Forming ◽  
Total Processing Time ◽  
Processing Efficiency ◽  
Bending Angle

Inverse problem in laser forming involves the heating position planning and the determination of heating parameters. In this study, the heating positions are optimized in laser forming of single curved shapes based on the processing efficiency. The algorithm uses a probability function to initialize the heating position that is considered to be the bending points. The optimization process is to minimize the total processing time through adjusting the heating positions by considering the boundary conditions of the offset distances, the minimum bending angle, and the minimum distance between two adjacent heating positions. The optimized results are compared with those obtained by the distance-based model as well as the experimental data.

An analytical formula for estimating the bending angle by laser forming

2006 ◽  
Vol 220 (2) ◽  
pp. 243-247 ◽  
Author(s):  
H Shen ◽  
Z Yao ◽  
Y Shi ◽  
J Hu
Keyword(s):  
Experimental Data ◽  
Solid Mechanics ◽  
Present Model ◽  
Analytical Formula ◽  
Laser Forming ◽  
Compatibility Conditions ◽  
Bending Angle ◽  
Metal Plates ◽  
External Forces ◽  
Simple Analytical Formula

Laser forming of metal plates offers the advantages of requiring no external forces and thus reduced cost and increased flexibility. It also enables forming of some materials and shapes that are impossible by using the traditional methods. Based on the conventional equilibrium and compatibility conditions used in solid mechanics, a simple analytical formula for predicting the bending angle is derived. The present model is compared with other models and available experimental data, from which the superiority of the present model is demonstrated.

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