Study On Fatigue Life Of Steel Structure Crane Beam In Service

In recent years, the survey results show that under the action of cyclic loading most of steelcrane beam with the crane of large tonnage, heavy duty or overweight-level work systemprematurely appear fatigue cracks of different degrees,which will endanger the safety in production.The fatigue life of the crane beams is often used as the key indicators of factory security control.Therefore, the study of the crane beam fatigue life is very meaningful, which cannot only preventand reduce the occurrence of disasters, extend the service life, but also can provide the basis data ofthe management for safe production of the future. At present, there is lack of better assessmentmethods. Therefore, it is very necessary to seek a more reasonable evaluation method in orderto more accurately calculate the fatigue life of the crane beam.This paper mainly used three methods of miner linear cumulative damage criteria analysismethod, fatigue damage accumulation model analysis method and DFR method to calculate thefatigue life of two crane beam. It can be found through the calculations and comparativeanalysis that fatigue life getting by calculating basically consistent with target life of cranebeam. And the results of calculating using DFR method can accurately assess steel crane beamstructure fatigue life.This article studies the impact of parameter changes which includes the effective stressconcentration factor, surface processing factor and structural size factor,etc on the structuralfatigue reliability life, and also discusses the influence of different parameters on it. Therefore,in the design stage, when the fatigue life does not meet the requirements, the measures ofimproving the design, increasing in size, reducing the stress concentration factor, and improve theprocessing quality of the surface should be considered to meet the target life requirements.The result of this paper further extends the application range of the DFR method.This paper discusses these relevant contents of the reinforcement life cycle prediction, costanalysis within the reinforcement life cycle and how to maintenance decision optimization Etc forexisting steel crane girder, and proposes a method to predict the reinforcement life cycle of the cranebeams based on reinforcement indicators and based on degradation rate difference of reliableindicator. This article puts forward the maintenance guidelines of the structure, and establishes theoptimization decision model based on the average annual cost. Engineering construction anddecision departments can use this model to make a more reasonable, economic and effectivedecisions on the maintenance and reinforcement of existing steel crane girder.