The paper reports some results on the issue of the thickness influence on the fatigue strength of welded joints. It is indeed well known that the recommendations of the current Codes used for ship structures are based on the results obtained for quite thick plates, and are applied also to relatively thin plates. For thicknesses greater than 25 mm a “thickness reduction factor” is considered, while no “thinness effect bonus” is foreseen for small thicknesses.
A series of experimental tests has been carried out in order to investigate the response to high-cycle fatigue of butt-welded joints of thickness less than 25 mm. In order to avoid time-consuming procedures, the analyses have been performed resorting to the Thermographic Method, already successfully adopted to predict the fatigue behaviour of ship structures.
