Product Code: ICAL05_106

The Effect of Beam Geometry on Stress Distribution in Laser Bending of Tubes
Authors:
Shakeel Safdar, The University of Manchester; Manchester UK
Lin Li, The University of Manchester; Manchester Lancs Great Britain
M.A Sheikh, The University of Manchester; Manchester Lancs UK
Zhu Liu, The University of Manchester; Manchester Lancs UK
Presented at ICALEO 2005

Laser forming is a spring back free, non-contact forming method. Compared to the mechanical bending, no hard tooling, dies or external force is used. Laser forming in recent years have received considerable attention. Within laser forming; tube bending is an important industrial activity, the final product being used in critical engineering systems like heat exchangers, hydraulic systems, boilers etc, etc. Laser tube bending utilises the thermal stresses generated during laser scanning to achieve the desired bends. The parameters to control the process are usually laser power, beam diameter, scanning velocity and number of scans. This paper investigates the effect of laser beam geometry on laser tube bending. Circular, rectangular, triangular and U shaped beam geometries are investigated. Finite element modelling has been used for the understanding of thermal history and stress distributions. The effect on material microstructure formation and geometry control is reported.