Finite element analysis of evaporative cutting with a moving high energy pulsed laser

A computational model for simulation of pulsed laser-cutting process has be en developed using a finite element method, An unsteady heat transfer model is considered that deals with the material-cutting process using a Gaussia n wave laser beam in a pulsed mode. An iterative scheme is used to handle t he geometric nonlinearity due to the melting region. The convergence study with mesh refinements and time steps first identifies optimal mesh and time step for the present analyses. Numerical analyses are carried out on the a mount of material removal and groove smoothness with laser power (LP) and n umber of pulses (NPS) while other laser cutting parameters are fixed. The r esults show that there exist threshold values in number of pulses and laser power in order to achieve two predetermined conditions: (1) amount of mate rial removal and (2) smoothness of groove shape. These values form an envel ope called threshold curve that separate the acceptable region from unaccep table one for quality pulsed laser cutting, The effect of velocity also lea ds to another threshold curve which is determined from both number of pulse s and velocity. Finally, the convergence of results in error domain is show n oscillating due to geometric nonlinearity. (C) 2001 Elsevier Science Inc. All rights reserved.