| In recent years,with the remarkable achievements of China's economic development,the position of cranes in the manufacturing industry has become more and more important,and the requirements and demands for the tonnage and span of bridge cranes in national production are also increasing.Cranes operating in steel mills,docks,etc.often need to face harsh working conditions and heavy lifting tasks,and the safety of bridge cranes has received widespread attention.Therefore,it is particularly important to evaluate the fatigue life of the main girder of the bridge crane and calculate the remaining life of the metal structure.This paper develops a set of bridges by studying the definition of crane life damage and several types of currently used fatigue life algorithms,and based on the high cycle fatigue characteristics of bridge cranes,combined with the advantages and disadvantages of structural fatigue life algorithm and normative algorithm.Double path life assessment system for cranes.The system includes a crane operation data acquisition system to calculate the fatigue life of the bridge crane from the stress angle,and combines the typical working conditions and lifting tasks in the crane's life cycle to analyze the remaining life of the bridge crane according to the design specifications.The research contents and results of this system are as follows:(1)The fatigue damage of metal structures is studied.The different types of analysis methods of high-cycle fatigue and low-cycle fatigue of hoisting machinery are discussed.The fatigue life stress method and the standard reverse-calculation double-path fatigue life calculation method are used to evaluate the life and obtain More scientific test results.(2)The finite element software ANSYS was used to establish a simplified model of the bridge beam of the bridge crane.According to the investigation record,four typical working conditions were designed for loading simulation.The stress cloud diagram was used to determine the main beam flange plate as a dangerous position for sensor installation.(3)According to the crane specification requirements,the signal source required for the test is counted,the type of sensor suitable for the test bridge crane is selected,the acquisition card module and the integrated acquisition panel are designed,and the sensor and strain gauge are installed in the field for data acquisition,and multiple groups are valuable of crane operation data.(4)Summarize the various data results of the bridge crane under test,carry out the double path estimation calculation process of the crane fatigue life,and use the strain data obtained by the acquisition system to calculate the total fatigue life at the survival rate of 99.9% through the stress method calculation process;Lifting height,displacement distance and lifting weight data give the working level of the crane component at the current stress state level.(5)The fatigue life of the bridge crane obtained by the stress method path and the normal method path is compared.Determine the type of fatigue life,and set the three remaining life analysis according to the life difference time of the calculation result,use the record of the used time of the bridge crane in the data acquisition system,or check the historical work record of the old crane under test and In the typical event,the total life ratio is calculated by using the speculative path of the estimated life of the crane,and the remaining life of the stress path is further calculated. |
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