Hello

Fatigue at spot welds can be determined by a series of experimental experiments. Experiments can be simulated with CAD / CAM / CAE programs (ANSIS or ABACUS) or real experiments. And the second case must be ascertained by what degree of cyclic loading can occur dying of the joint. It is good to know the load pattern, the material - basic and welding joining and the massive impact force.

Wishing for success in scientific research.

Emil Yankov

For your kind information fatigue performance is not dependent on base material or its strength.it only depends on thickness or weld Dia. Since there is local plastic deformation it is difficult to find out the exact stresses generated around spot weld however by radj rupp model one can find forces and moments and try to calculate the structural stresses locally...and stresses are calculated in nastran.however talking experimentally in an industrial network there should be some quality standards that one can make for acceptance and not acceptance of a product.since nugget diameter will not be there...how do we then evaluate the performance....I hope u under my text now very well...

It is known that fatigue also depends on the material, because each material has a chemical composition that directly depends on the mechanical behavior of the material. In addition, each material also has a micro-structure which has a strong influence on the behavior of the material in the process (cyclic loading). In a fine-grained structure, the materials improve their mechanical properties and vice versa. In a large structure, conditions are created for earlier cracking. When we have a local point weld, then we have large gradients of grains from small to large grains due to different flow velocity. This is one of the reasons why early fatigue arises around the weld.