On the fatigue design of K-joint tubular girders

Abstract

The fatigue design of welded tubular lattice structures is preferably based on the hot-spot stress method, combining nominal stresses and Stress Concentration Factors (SCF). In the present paper, the fatigue design of K-joint tubular girders is investigated through an extensive numerical study, with emphasis on the effects of joint flexibility. It is shown that these effects are quite significant, especially fur nominal bending stresses. Results are reported with respect to both the nominal stress level and the hot-spot stress level (through the use of appropriate SCFs). The results of the present study are summarized in a simple and efficient design methodology.