The work concerns the numerical modelling of coupled thermal and mechanical phenomena occurring in the laser beam welding process. Commercial Abaqus FEA engineering software is adopted to numerical computations in order to perform a comprehensive analysis of thermo-mechanical phenomena. Created in Fortran programming language additional numerical subroutines are implemented into Abaqus solver, used to describe the power intensity distribution of the movable laser beam heat source. Temperature dependent thermomechanical properties of X5CrNi18-10 steel are adopted in the numerical analysis of stress and strain states. Mathematical and numerical models are verified on the basis of a comparison between selected results of computer simulations and experimental studies on butt-welded joints.
Numerical simulations are presented for steel sheet with a thickness of 2 mm. Temperature distributions, the shape and size of melted zone as well as residual stress and deformations are presented for analyzed elements. Numerically determined deflections are compared with the measured deflection of welded joint.
 D. Deng, H. Murakawa, Comp Mater Sci. 43, 353 (2008).
 H. Long, D. Gery, A. Carlier, P.G. Maropoulos, Mater Design. 30, 4126 (2009).
 D. Deng, Mater Design. 30, 359 (2009).
 D. Gery, H. Long, P. Maropoulos, J Mater Process Tech. 167, 393 (2005).
 J. Pilarczyk, M. Banasik, J. Stano, Przeglad Spawalnictwa. 5-6, 6 (2006).
 M. Węglowski, S. Stano et al., Mater Sci Forum. 638-642, 3739 (2010).
 W. Piekarska, Numerical analysis of thermomechanical phenomena during laser welding process. The temperature fields, phase transformation and stresses, Wydawnictwo Politechniki Częstochowskiej (2007).
 A. Bokota, W. Piekarska, Paton Weld J. 6, 19 (2008).
 P. Lacki, Z. Kucharczyk, R.E. Śliwa, T. Gałaczyński, Arch Metall Mater. 58, 597 (2013).
 W. Piekarska, M. Kubiak, Z. Saternus, Arch Metall Mater. 58, 1391 (2013).
 Z. Moumni, F. Roger, N. Thuy Trinh, Int J Plasticity. 27, 414 (2011).
 L. Tian, Y. Luo, Y. Wang, X. Wu, Mater Design. 54, 458 (2014).
 X. Shan, C.M. Davies, T. Wangsdan, N.P. O'Dowd, K.M. Nikbin, Int J Pres Ves Pip. 86, 110 (2009).
 A. Anca, A. Cardona, J. Risso, et al., Appl Math Model. 35, 688 (2011).
 Abaqus theory manual, Version 6.7, SIMULIA Dassault System (2007).
 Z. Malinowski, T. Telejko, B. Hadała, Arch Metall Mater. 57, 325 (2012).
 L. Sowa, A. Bokota; Archives of foundry engineering. 11, 139 (2011).
 S.A. Tsirkas, P. Papanikos, Th. Kermanidis, J Mater Process Tech. 134, 59 (2003).
 L. Sowa, Archives of foundry engineering. 14, 103 (2014).
 T. Skrzypczak, E. Węgrzyn-Skrzypczak, Int J Heat Mass Tran. 55, 4276 (2012).
 A. Bokota, T. Domański, Arch Metall Mater. 52, 277 (2007).
 A. Bokota, T. Domański, Arch Metall Mater. 54, 575 (2009).
 W. Piekarska, M. Kubiak, Z. Saternus, K. Rek, Arch Metall Mater. 58, 1237 (2013).
 D. Deng, H. Murakawa, Comp Mater Sci. 37, 269 (2006).