Controlling Edge Effects in Laser Bending

Laser forming of sheet metal offers the advantages of requiring no hard tooling, no spring back and no external force. Thus this technology reduces cost, increases flexibility and accuracy. Laser forming is a complicated and transient thermo-mechanical process involving elastic and plastic strain dependent on time history. How to control and enhance the accuracy of the laser forming attracts much attention. This paper put forward a new strategy to control and reduce the edge effects in laser forming. Numerical simulations and experiments were also carried out to validate the presented strategy.

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Analysis and Prediction of Edge Effects in Laser Bending

Journal of Manufacturing Science and Engineering ◽

10.1115/1.1345729 ◽

2000 ◽

Vol 123 (1) ◽

pp. 53-61 ◽

Cited By ~ 72

Author(s):

Jiangcheng Bao ◽

Y. Lawrence Yao

Keyword(s):

Residual Stress ◽

Edge Effects ◽

Laser Scanning ◽

Laser Forming ◽

Stress Distributions ◽

Rate Dependency ◽

Laser Bending ◽

Numerical Investigations ◽

Wide Range ◽

Scanning Path

Laser forming of sheet metal offers the advantages of requiring no hard tooling and thus reduced cost and increased flexibility. It also enables forming of some materials and shapes that are not possible now. In single-axis laser bending of plates, the bending edge is found to be somewhat curved and the bending angle varies along the laser-scanning path. These phenomena are termed edge effects, which adversely affect the accuracy of the bending and result in undue residual stress. Numerical investigations are carried out to study the process transiency and the mechanism of the edge effects. Temperature dependency of material properties and strain-rate dependency of flow stress are considered in the numerical simulation to improve prediction accuracy. Numerical results are validated in experiments. Patterns of edge effects and resultant residual stress distributions are examined under a wide range of conditions. A more complete explanation for the mechanism of the edge effects is given.

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Study of Edge Effects in Laser Bending

10.1115/imece1999-0760 ◽

1999 ◽

Author(s):

Jiangcheng Bao ◽

Y. Lawrence Yao

Keyword(s):

Edge Effects ◽

Material Properties ◽

Laser Forming ◽

Temperature Dependency ◽

Rate Dependency ◽

Laser Bending ◽

Angle Variation ◽

Bending Angle ◽

Numerical Studies ◽

Strain Rate Dependency

Abstract Laser forming has not been widely used due to limited understanding of its mechanism and immaturity of processing technology. In the study of single axis laser bending of plates, edge effects affect accuracy of the bending. Experimental and numerical studies are carried out to study the mechanism of the edge effects. Temperature dependency of material properties and strain-rate dependency of yield stress are considered in numerical simulation. Numerical results match well with experimental results. Patterns of edge effects are examined in terms of bending angle variation and curved bending edge under different conditions. A more complete explanation for the mechanism of the edge effects is given.

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