TWI Industrial Member Report Summary 636/1998
T R Gurney
The great majority of fatigue test results for welded joints have been obtained using specimens approximately 13mm thick and, as a result, fatigue design standards tend to be based upon these results. However, over recent years it has been shown that, for many types of joint, as thickness increases fatigue strength tends to decrease, as predicted by fracture mechanics calculations. In consequence, fatigue design stresses for thick joints have been reduced in some standards.
However, as far as thin joints are concerned, there are very few relevant test results, although there is some reason to believe that, as thickness decreases, fatigue strength will tend to increase (at least for joints with welds transverse to the direction of stress). The main objective of this work was therefore to carry out a theoretical assessment of the strengths of both non-load-carrying and load-carrying joints with transverse fillet welds.