Fatigue Prognosis Analysis on the Cracked Steel Crane Runway Girders Under High Temperature

In order to resolve the fatigue fracture problem of the steel crane runway girders (CRGs) with a surface crack under high temperature, fatigue prognosis analysis on the cracked CRGs has been performed. Three dimensions finite element models for cracked CRGs have been established using ABAQUS and the fatigue-creep crack propagation of the CRGs under high temperature has been simulated. A fatigue-creep life prediction method for the cracked CRGs at high temperature has been developed based on the obtained numerical results and Saxena theories. The influence of runway eccentricity and overloading effect on the crack propagation have been studied, respectively. It turns out that the runway eccentricity exhibits little influence on propagation of the crack at the weld joint between web plate and lower flange of the CRG. The fatigue-creep life of the cracked CRGs at high temperature has been predicted under different wheel loading condition. The fatigue-creep life of CRGs ranges from about 234–48 days under the condition where the wheel loading increases from 300 to 450 kN. The overloading effect significantly accelerates the crack propagation and the fatigue-creep life of the CRG under 10% overloading has been shortened about 41.7% compared with that under full loading condition.