0
TECHNICAL PAPERS

Effects of Scanning Schemes on Laser Tube Bending

[+] Author and Article Information
Jie Zhang, Peng Cheng, Y. Lawrence Yao

Department of Mechanical Engineering, Columbia University, New York, NY 10027

Wenwu Zhang, Michael Graham, Marshall Jones

Global Research Center, General Electric Company, Niskayuna, NY 12309

Jerry Jones

 Native American Technologies Company, Golden, CO 80401

J. Manuf. Sci. Eng 128(1), 20-33 (Jun 11, 2005) (14 pages) doi:10.1115/1.2113047 History: Received August 11, 2004; Revised June 11, 2005

Four laser scanning schemes for tube bending, including point-source circumferential scanning, pulsed line-source axial procession, and line-source axial scanning without and with water cooling are investigated in numerical simulation. The coupled thermomechanical model established using the finite element method is validated and applied to predict the bending deformation and help better understand bending mechanisms under different schemes. The influence of important parameters such as beam coverage, scanning velocity and cooling offset on the deformation is investigated in detail. Parametric studies are carried out to determine proper processing windows at which the largest bending can be obtained. The deformation characteristics, including the wall thickness variation and the cross-section distortion produced by different scanning schemes are analyzed, along with the processing efficiency.

Copyright © 2006 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

Schemetic of scanning schemes. (a) Circumferential scanning by a point laser source. (b) Axial scanning by a line laser source and cooling scheme.

Grahic Jump Location
Figure 2

FEM simulation validation with experimental results (scheme I)

Grahic Jump Location
Figure 3

Distribution of axial plastic strain along the circumferential position under scheme I, the point-source circumferential scanning scheme (a) at the center of heat affected zone; and (b) at the location slightly off the center of heat affected zone

Grahic Jump Location
Figure 4

Cutoff schematic of bent tube with axial plastic strain (PE33) along the intrados under scheme II, the pulsed line-source axial procession scheme (deformation ×50, irradiating time: 1s, beam width: 4mm, energy intensity: 8J∕mm2, outer diameter of tube: 12.7mm, tube thickness: 0.89mm)

Grahic Jump Location
Figure 5

Relationship of beam coverage with bending angle under scheme II, the pulsed line-source axial procession scheme

Grahic Jump Location
Figure 6

Simulated time history of temperature with different beam coverage values under scheme II (0.2s time delay between two cases for viewing clarity)

Grahic Jump Location
Figure 7

Distribution of the circumferential- and axial-plastic strain at outer surface along the intrados, under scheme II, the pulsed line-source axial procession scheme

Grahic Jump Location
Figure 8

Time history of circumferential- and axial-plastic strain of outer surface at the location slightly off the line-source center under scheme II, the pulsed line-source axial procession scheme

Grahic Jump Location
Figure 9

Cutoff schematic of bent tube with typical FEM contour of axial plastic strain (PE33) under scheme III, the line-source axial scanning scheme (deformation ×5, laser power: 1550W, scanning velocity: 20mm∕s, beam width: 4mm)

Grahic Jump Location
Figure 10

Variation of bending radius with velocity under a constant peak temperature approach under scheme III, the line-source axial scanning scheme

Grahic Jump Location
Figure 11

Comparison of temperature distribution along the intrados when the line-source center reaches a typical position of the tube under scheme III, the line-source axial scanning scheme

Grahic Jump Location
Figure 12

Distribution of axial plastic strain along the intrados at different velocity values under scheme III, the line-source axial scanning scheme

Grahic Jump Location
Figure 13

Comparison of temperature distributions (NT11) under the line-source axial scanning without and with cooling schemes (schemes III and IV) (laser power: 1550W, scanning velocity: 20mm∕s, beam width: 4mm, cooling offset: 50mm)

Grahic Jump Location
Figure 14

Comparison of the time history of axial plastic strain at the center of intrados under the condition of the line-source axial scanning w/cooling and w/o cooling

Grahic Jump Location
Figure 15

Variation of the bending radius with cooling offset (which is defined as the half length at major axis of water sprinkler, see Fig. 1)

Grahic Jump Location
Figure 16

Simulated temperature history of the outer surface at the center of intrados under different cooling offsets I

Grahic Jump Location
Figure 17

Simulated and experimental results using line-source axial scanning with water cooling for tube outer diameter: 12.7mm, wall thickness: 0.89mm, and tube length: (a) 600mm, with the FEM contour of axial plastic strain (PE33) and (b) 1800mm

Grahic Jump Location
Figure 18

Wall thickness variations under different scanning schemes [(a) scheme I, power=780W, velocity=1.57rad∕s, beam diameter=11mm; (b) Scheme II, power=425W, irradiating time=1s, beam width=4mm; (c) Scheme III, power=1550W, velocity=20mm∕s, beam width=4mm; (d) Scheme IV, power=1550W, velocity=20mm∕s, beam width=4mm, cooling offset=50mm]

Grahic Jump Location
Figure 19

Cross-section distortions under different scanning schemes [(a) Scheme I, power=780W, velocity=1.57rad∕s, beam diameter=11mm; (b) Scheme II, power=425W, irradiating time=1s, beam width=4mm; (c) Scheme III, power=1550W, velocity=20mm∕s, beam width=4mm; (d) Scheme IV, power=1550W, velocity=20mm∕s, beam width=4mm, cooling offset=50mm]

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In