Research On The Fatigue Analysis Methods Of Welding Structure And Applied To The Tower Crane Boom

Welding structure fatigue is a very complex issue involving many factors in thecourse of the study, combined with significant gap between the actual operatingconditions and the experimental conditions of the structure, researchers have done a lotof work in this regard and achieved certain results, but they have not obtained a moreversatile and precise conclusions for metal fatigue strength and fatigue life of weldedstructures. Tower crane is a typical metal welded structure, its load factor and busydegrees also increased significantly with the rapid development of the constructionindustry. In recent years, the tower crane accidents occur sometimes and an upwardtrend, a large part of the tower crane accidents caused due to the fatigue of structuralparts according to industry surveys.The basic knowledge of the theory of fracture mechanics and the theory ofstructural fatigue analyzed in this paper, the load conditions of tower crane and thefatigue type of welding structure, the method used to calculation the fatigue life of thetower crane summed. Take QTZ40tower crane production in a factory of ShaanxiProvince as the research object, the solid finite element model of single section of thetower crane boom establishment and the size and distribution of the welding residualstress welding of structural calculated. Against the characteristics of the Tower craneboom structural, different welding programs have development, welding residual stressunder different welding sequence calculated by the finite element analysis software,the impact on welding residual stress of welding sequence and the impact on fatiguelife of load structure of welding residual stress. The finite element model of QTZ40tower crane boom established, welding residual stress is applied on the finite element model, stress size and distribution of tower crane boom under various conditions arecalculation according to the lifting curve. Combined with actual operating data of thesame type of tower crane in references, established load spectrum, the fatigue life oftower crane boom is calculated by fatigue analysis software MSC.Fatigue. Analysis thecalculation results, study on the impact of fatigue life of tower crane boom withwelding residual stress and external load and the results can guide the safe use of towercrane and design and manufacture of next-generation tower crane.