COMPARISON OF ANALYTICAL, NUMERICAL AND EXPERIMENTAL SOLUTIONS TO PROBLEMS OF DEEPLY CRACKED WELDED-JOINTS IN BENDING

This paper presents analytical and numerical solutions to the analysis of welded specimens when loaded in three-point bending, and compares the results with those obtained experimentally. In each case the crack is located within the weld material, and runs parallel to the weld. T wo analytical models are presented for deriving limit loads using slip -line field theory. Due to the welding process, the material behaviour in the weld-base interface is complex, and this is described in the a nalytical solutions using a number of material zones. The analytical s olutions also provide the eta and d(infinity), coefficients which are used to determine the J and crack tip opening displacement (CTOD) para meters. These solutions are then compared with numerical results obtai ned using the finite element method. Good agreement is obtained betwee n the numerical and analytical results, and it is shown that for overm atched specimens a better analytical solution can be obtained by using a slip-line field geometry which passes predominantly through the bas e material. When the analytical eta solutions are applied to the exper imental results it is shown that, in the case of undermatched weldment s, J can be used as a fracture characterising parameter, but it cannot be used in the case of an overmatched specimen.