Laser forming of plates using rotating and dithering beams

Laser forming is a useful process for flexible forming, during which a laser beam causes deformation of a plate. In this work we introduce a new method for laser forming of plates that is laser forming with rotating and dithering beam. In laser heat treatment of steel some method is used to produce a wider and nearly uniform average irradiance profile. It may be achieved by rotating the beam optically, thereby producing an overlapping spiral track or by dithering the beam (rocking the lens or mirror) perpendicular to the track, thus producing a zigzag pattern. In this study an analytical solution and a numerical solution is developed for a transient heat conduction equation in which a plane slab is heated by a rotating or dithering laser beam over the upper surface. The temperature distribution was then input as a body load for the three-dimensional nonlinear structural analysis to determine the bending angle and distortions. The result of structural analysis show that the bending angel of laser forming using rotating and dithering beam in similar condition are several times more than the bending angel of laser forming using a beam which move along a straight line with uniform velocity.