Computational simulation of the laser cutting process

This paper describes the implementation and numerical evaluation of a transient three-dimensional computer simulation of the CO₂ laser cutting process. Utilising Crank-Nicolsen-Finite-Difference equations for the solution of the Fourier heat transfer equation with Newtonian convection, the temperature distribution is predicted. For high accuracy the mesh is of non-equidistant nature, following a Weibull Distribution for the grid spacing. A parallel computation solver will be used, based on Aztec (a parallel iterative library for solving linear systems - www.sandia.gov), to calculate the nodal temperatures using a cluster of two HP J5000 workstations. Included in the solution is the behaviour of the material during phase change, whilst the open structure of the developed software allows incorporation of effects such as surface oxidation, radiation and limited convective flow. The main area of interest is the cutting capability with respect to varying material thickness (e.g. tailored blanks), cutting speed, power of the laser, laser mode, focal spot diameter and material properties, as well as the effect of these parameters on the quality of the cut. Further developments will also be outlined in this paper.