Abstract: A computer system is developed which can predict the weld solidification cracks for weldment in two dimensions. Firstly, the pre-data-treatment subsystem helped users to discretize the workpiece, calculate heat generation and the time to add or remove the nodes of the welding molten pool, input the physical properties of materials and generate a calculated card for final FEM calculation. Secondly, the system transferred the calculated cards to software package of Adina&t to complete the calculation of thermal, strain and stress distributions. Next, the post-data treatment section could deal with the calculated data and display the results in featured curves, contours and 3D figures. Lastly, the system regressed the experimental data of trans-varestraint test to obtain the resistance curve of weld solidification cracks and had it compared with the driving force in the same figures and thus predicted the possibility of weld solidification cracks. The system is completed with computer languages Visual Basic 6.0 by combining with the matrix calculating and graphic functions of Matlab 5.3 and Matrix VB to realize the display the graphs.

Key words: Numerical simulation, Strain and stress fields, Welding solidification cracks