Fatigue analysis of multiaxially loaded crane runway structures including welding residual stress effects

The paper addresses a fatigue evaluation procedure to assess the influence of both multiaxial stress state caused by a traveling crane wheel load and the welding residual stresses on the lifetime of crane runway girders. The behavior of the residual stresses during cyclic loading was investigated separately. Numerical calculation of welding residual stresses was conducted within a first step. Cyclic stress–strain curves of specimens both from the weld region and the base material were evaluated in strain-controlled uniaxial cyclic specimen tests as a basis for the fatigue assessment. Numerical investigations by means of elastic–plastic finite element analyses were carried out to estimate the local stress conditions acting in the weld notches. The local stresses and strains were post-processed within the MPA AIM-Life concept using critical plane approach and advanced fatigue parameters. The lifetime of crane runways was calculated both with and without residual stress effects. Finally, the estimated lifetimes were compared to experimental results of component fatigue tests on full-scale crane runway girder tests with traveling wheel load.