This master thesis is a study to determine if there is a simple to use but still accurate way to determine if a simulated MIG/MAG weld is close to failure. A material, which has been exposed to welding usually shows changes in properties like hardness since a local warming around the weld occurs. The heat-affected zone and the weld itself can easily become the weak link when the material is under external loading. For a precise way to capture the cracking, a high-density mesh is required which in the everyday work would demand too long simulation time, which in turn would make the work cost- inefficient. The requirement of this thesis is not to visualize an accurate procedure at crack initiation and propagation, but to find an easy measurement to get an indication if a weld is at risk. This ensures that mistakes in the design during the development are detected at an early stage. To find a simple measurement, tests were made on some simple test-pieces. These tests were then simulated in LS-dyna in order to compare the results. The results were tested on larger and more complex models for verification. The conclusions from these simulations were satisfying. The problem is solved by controlling the shear stress within the weld, which can be done during post processing of the simulation. This method is verified and considered successful for identification of a MIG/MAG weld close to failure.
Validerat; 20101217 (root)