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Laser beam cutting technology is becoming increasingly popular in various industries. Advantages of this method is a very high cutting speed and a precision of edges of cut elements. Good quality depends on many technological parameters. Numerical prediction of the effect of cutting process parameters on the quality of the surface can be useful for technologists. The work concerns the numerical analysis of the laser cutting process of sheet made of steel. The influence of selected parameters on the energy efficiency of the heat source and the cutting speed are analyzed. Numerical calculations are performed in Abaqus software. Three-dimensional discrete model of the analyzed system is developed. The standard material parameters of austenitic steel changing with the temperature are taken into account. Gauss model describing the distribution of movable heat source of a laser beam power are assumed in the solution algorithms. The influence of various parameters of the laser beam on obtained temperature field and shape of cut zone is estimated on the basis of numerical calculations. The results are compared with the results of the experiment.

This work concerns numerical modelling and computer simulations of temperature field and phase transformations during Yb:YAG laser heating of sheets made of S355 steel. The distribution of laser power emitted by Trumpf laser head D70 is used in the analysis. The heat source is modelled on the basis of interpolation algorithms using geostatistical kriging method. Coupled heat transfer and fluid flow in the fusion zone are described respectively by transient heat transfer equation with convective term and Navier-Stokes equation. The kinetics of phase transformations and volumetric fractions of arising phases are obtained on the basis of Johnson-Mehl-Avrami (JMA) and Koistinen-Marburger (KM) models. Continuous Heating Transformation (CHT) diagram is used for heating process and Continuous Cooling Transformation (CCT) diagram is used for heated steel with the decomposition of final volume fractions of phases transformed form austenite dependant on cooling rates.

This work concerns mathematical and numerical modelling of temperature field during Yb:YAG laser heating of sheets made of S355 steel with the motion of liquid steel in the fusion zone taken into account. Laser power distribution and the caustics are determined on the basis of the geostatistical kriging method. Temperature field and melted material velocity field in the fusion zone are obtained from the numerical solution of continuum mechanics equations using projection method and finite volume method. Numerical algorithms are implemented into computer solver using ObjectPascal programming language. Computer simulations of Yb:YAG laser heating process are performed for different process parameters. Characteristic zones of experimentally obtained cross sections of heated elements are compared to numerically predicted fusion zone and heat affected zone.

The numerical analysis of laser welding process with consideration analytical methods determining phase transformations and mechanical properties of welded joints are presents in this paper. The analytical CCT diagram and final structural composition of S355 steel are presented. The empirical relations presents in paper are determined by chemical compositions investigated steel and cooling rate between temperatures 800-500°C (t8/5). Phase composition and mechanical properties each of structures of steel in weld and heat affected zone (HAZ) are determined on the basis of analytical methods. Laser welded flat is used in numerical simulations in ABAQUS. Mathematical modes of volumetric welding source are used in the calculations. Temperature fields, shape and size of melting zone for selected points in the cross-section of the joint are determined on the basis of thermal cycles obtained numerical.

The paper concerns numerical analysis of thermal phenomena occurring in the butt welding of two different materials by a laser beam welding. The temperature distribution for the welded butt-joint is obtained on the basis of numerical simulations performed in the ABAQUS program. Numerical analysis takes into account the thermophysical properties of welded plate made of two different materials. Temperature distribution in analysed joints is obtained on the basis of numerical simulation in Abaqus/Standard solver, which allowed the determination of the geometry of laser welded butt-joint.

This paper concerns mathematical modelling of caustics of solid state laser YAG type with the disk active medium. The heat source model is developed on the basis of interpolation algorithms using geostatistical kriging method. The real laser beam power distribution and caustics are taken into account in the model. Measurements of laser beam power distribution and diameter of the laser beam spot for different focusing are performed using UFF100 analyzer. Yb:YAG laser emitted by Trumpf laser head D70 is used in the experiment. Presented results include the comparison of experimentally determined laser power intensity distribution and caustic with results obtained by developed interpolation model.

Laser welding technology is applied to many types of welded joints. The determination of the influence of technological parameters on the properties of resulting joint is a significant problem for technologists. Numerical estimation of the shape of the weld and its deformation is important in the initial stage of construction design. The paper concerns computer analysis of thermal and mechanical phenomena in laser welded lap joint made of austenitic steel. Three dimensional discrete model of analyzed lap joint is created in Abaqus FEA engineering software. Numerical analysis takes into account temperature dependent thermomechanical properties of austenitic steel. The movable heat source power distribution is modelled using Gaussian distribution. Computational model takes into account the gap between the joined plates. Temperature distribution in analysed joints is presented on the basis of performed numerical simulations. The shape and size of the fusion zone as well as deformation of the joint are estimated.

The mathematical model and numerical simulations of the mechanical phenomena in the gantry crane are presented in this paper. The design of modern mechanical constructions is a complex task that requires use of appropriate tools. Such a modern tool, that gives a broad opportunity to analyze strength parameters of designed structures, is numerical simulation which uses the various numerical methods. Here the problem was solved by the finite element method. The analysis of the stresses and strains of the structure of gantry crane was made using the advanced software with highly efficient possibilities of modeling. Motion of the crane trolley along the beam was also taken into account in the study. The research performed, allows the evaluation of the stress state, pointing out the critical areas and values which are made in order to increase the strength of the structure of the gantry crane. The results of numerical simulation are presented in the form of the fields of Huber-Misses stress for the selected location of the crane trolley. [ABSTRACT FROM AUTHOR]

Numerical modeling of thermal phenomena with the motion of fusion zone in the welding pool taken into account is performed in this study for hybrid welding process using Yb:YAG laser with electric arc in GMAW method. New hybrid heat source model is developed on the basis of classical Goldak model for the electric arc and interpolation model for the laser beam with the experimental data of Yb:YAG laser beam distribution taken into account. Temperature field and melted material velocity field are calculated on the basis of numerical solution into mass, momentum and energy conservation equations in finite volume method with Chorin's projection method. Computer simulations of temperature field and melted material velocity field are performed in the welding pool for different distances between heat sources. The comparison of numerically estimated geometry of characteristic zones of joints with macroscopic pictures of cross sections of welds is made in order to evaluate the suitability of developed numerical model in industrial applications. [ABSTRACT FROM AUTHOR]

This paper concerns the modelling of laser beam heat source based on experimental research of Yb:YAG laser. Measurements of the real laser beam power emitted by Trumpf laser head D70 are performed using UFF100 analyser. Developed heat source interpolation model is based on the geostatistical Kriging method. Comparison of experimentally determined Yb:YAG laser power intensity distribution with analytical models and interpolated distribution is carried out in order to determine the accuracy of mapping of the real laser beam heat source distribution. Finally, numerical simulation of laser heating process is performed in finite element method to evaluate the usefulness of presented solutions. [ABSTRACT FROM AUTHOR]