The article presents a comparison of modern computational techniques used in numerical analyses of welding processes. The principles of the “transient” technique calculations with a moving heat source, the “macro-bead” (MBD) technique, with an imposed thermal cycle on a selected weld bead section and the “local–global” approach with shrinkage calculation technique were described. They can be used, depending on the variant chosen, both for individual, simple weld joints and those made of many beads or constructions containing dozens of welds and welded elements. Differences in the obtained results and time needed to perform calculations with four different calculation examples of single and multipass arc and laser beam welding processes were presented. The results of calculations of displacements and stresses distributions in the welded joints using various computational techniques were compared, as well as the calculation times with the described techniques. The numerical analyses in the SYSWELD software package have shown the differences between the described computational techniques, as well as an understanding of the benefits and disadvantages of using each of them. This knowledge allows preparing an efficient and fast optimization of the welding processes, often aimed at minimizing deformations in the first place, as well as detection of potential defects of both simple and complex welded structures. In general, the possibilities and flexibility of modern numerical calculation software have been presented.

This article presents examples of numerical simulations done based on the real experiments of S700MC steel T-joint laser and hybrid welding. Presented results of numerical analyses carried out using SYSWELD show the possibilities offered to contemporary engineers by modern software used to make numerical analyses of production processes. After calibration of a heat source models on the chosen examples of S700MC steel 10-mm-thick T-joint laser and hybrid welding, distributions of temperature fields, thermal cycles, distributions of individual metallurgical phases and hardness, and strains and plastic deformations in simulated processes were calculated for one selected joint from both mentioned methods. The results of the analysis allow determining both the differences in the stress distributions and their minimal and maximal values. This article also presents the benefits resulting from the use of such analyses, due to the significant savings in time and resources to be spent on the development of correct technologies for joining modern construction materials such as thermomechanically treated steels, especially given that some of the results are unavailable or very difficult to collect using conventional measurement methods.

The article presents new possibilities for modifying heat source models in numerical simulations of laser welding processes conducted using VisualWeld (SYSWELD) software. Due to the different power distributions and shapes of a laser beams, it was necessary to propose a modification of heat source models and methods of defining the heat introduced into a welded material in the case of simulations of welding processes using solid-state and high-power diode lasers. A solution was proposed in the form of modification of predefined heat source models in the case of simulations of welding processes using solid-state disc lasers and high-power diode lasers (HPDL). Based on the results of metallographic tests and the acquisition of thermal cycles of real laser welding processes, the process of calibration and validation of the proposed models of heat sources depending on the type of device used as well as the obtained shapes of fusion beads was carried out. The purpose and assumptions of this approach towards creating heat sources were also reported, comparing exemplary stresses and cumulative plastic strain distributions for the calculation variant using a standard and modified heat source model.

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Welding, as a modern and highly efficient technology, is presently applied in practically all industrial sectors. An increase in the number [1] Source URL: http://bulletin.is. gliwice.pl/article/use-welding-process-numerical-analysestechnical-support-industry-part-1