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This paper describes a numerical finite element method modeling of laser applications, especially laser cutting and drilling a steel, concrete or brick. In the first part of this contribution there is a very brief description of laser processing in metal (a kind of carbon steel) and non-metal material (concrete and brick), possibility of mathematical modeling and needful parameters for this modeling. One of the systems, that uses this method, is ANSYS. The ANSYS computer code is a large-scale multipurpose finite element program, which may be used for solving several classes of engineering analyses, for example thermal analyses, that calculates the temperature distribution and related thermal quantities in a system or its components. The main part of this paper deals with examples of temperature field computed by ANSYS in carbon steel, concrete and brick after incident of the high-power laser beam upon their surfaces. In conclusion we compare various theoretical results mutually and also with practically obtained facts.

This paper describes a possibility of mathematical modeling of laser applications, especially laser cutting and drilling and its use in practice. In the first part of this contribution there is a very briefly description of contemporary use of high-power lasers in industry and also basic principles of interaction between laser beam and treated material. Next part of the paper deals with a mathematical modeling of temperature field. Two numerical methods are used for the calculation of the temperature field: the finite difference method and the finite element method. Two examples of results of these both methods are demonstrated and some problems occurring when creating the matheniatical models are described. In the conclusion we made a brief comparison between theoretical and experimental results.

In this paper, there is described the influence of various modifications of the laser resonator on the energy of laser radiation studied for the application of material drilling. We used pulsed 150W Nd:YAG laser from LASAG AG company, Switzerland. This laser was developed for industrial material processing - cutting, welding and drilling. The diameter and divergence of the output laser beam can vary by replacement of optical elements in the laser resonator and by change of the distance between them. Heating of Nd:YAG crystal during laser action resulting in its function as an internal lens has an important effect on a beam quality. This quality is characterized by a beam parameter product depending on a charging power and type of resonator. The goal of our experiment is to find minimal parameters for cutting and drilling of some metallic sheets with thickness from 0.1 mm to 10 mm and to verify an increasing beam quality by reducing a laser output power and by modification of a resonator arrangement. Nitrogen was used as an assist gas. Measured experimental results were summarized in graphs and tables and were prepared for quick reference of laser parameters used for processing various work-pieces.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.