Research On Hotspot Stress Monitoring And Fatigue Damage Of Gantry Crane

The fatigue damage of hoisting machinery under random load will cause structural fatigue.When the fatigue damage accumulation reaches the limit,it will lead to structural failure,and lead to serious safety accidents and economic losses.The stress monitoring technology of track area crane hot area is studied,and fatigue damage prediction is carried out.It has guiding significance for safety management and operation maintenance of hoisting machinery.The analysis of fatigue loss is a data calculation process based on the structure load spectrum.The selection of fatigue load spectrum is directly related to the reliability of fatigue life prediction.In this paper,based on the research of stress monitoring technology,based on the selection of monitoring points,the direction of monitoring and the operation of monitoring means,we fundamentally weaken the instability of stress data acquisition,and improve the reliability of fatigue life prediction from the mathematical point of view.The main contents are as follows:1)The determination of the position of fatigue monitoring.According to crane accident statistics and metal damage mode research,fuzzy recognition method is applied to risk assessment of common fatigue crack structure,and high risk weld fissure area is determined.The multi-scale calculation of the material performance of high risk welds is realized by using the detection method.Finally,the determination of the risk points of the fissure area,that is,the determination of the monitoring points.2)Research on directional monitoring technology.The single point stress state is complex and changeable,and the stress can be measured by the principle of right angle strain flower,and the single point state can be accurately described.The data processing based on the Monte-Carlo method can effectively determine the direction of the main stress in the probability model,that is,the direction of the single point crack.The single point stress monitoring can be realized by using fiber Bragg grating sensors.3)Study on fatigue damage of crane.The operation mode of lifting machineryand the type of metal fatigue are discussed,and the fatigue life prediction process of the crane is analyzed by the nominal stress method.A series of steps,such as signal preprocessing and rain flow counting,are carried out for the force work spectrum,and the fatigue calculation based on linear cumulative damage is realized.4)The engineering application of fatigue monitoring.The stress monitoring system of the rail portal crane is used to analyze the fatigue damage equivalent and to realize the safety status of the whole machine.