The Analysis Of Strength And Ductility Of Fillet Welds With Crack-like Root Notch In Thick Plate

Due to structural reason, there be crack in two steel boards of fillet welds connection. Though, it does not be regarded as welding defects. It has crack-like effect like weld imperfect. The main purpose of this thesis is to study the effect of the weld root notch on strength and ductility of fillet welds.Based on the latest experimental data abroad, study the effect of the weld root notch on strength and ductility of fillet welds by means of finite element numerical analysis.1) According to the cruciform weld experiments, corresponding model has been constructed by using finite element analysis software-ANSYS. Comparing the results obtained from the experiments and finite element analysis, a very well agreement is found, showing the accuracy and feasibility of the simulation with finite element method.2) Effective finite elements simulations are conducted to discuss the large notch lengths. The results indicate that larger notch lengths don't further reduce the strength and ductility of the welds.3) The main influence factors on strength and ductility of fillet welds are analyzed in this paper. These factors are:two different weld specifications (E70T7-K2 and E70T7; both Grade 480 MPa), two different weld sizes (12mm and 8mm) and two different length of the root notch (32mm and 64mm).4) A review of Code for Design of Steel Structures (GB50017-2003) with American (AISC) and European Criterion (Eurocode3) is presented in this paper. The limitations and calculating methods of fillet welds in these criteria are calculated and compared. The results suggest that the Chinese code is relatively conservation. The European code has the highest design values.