Research And Development Of The Structural Health Monitoring System For Lifting Machinery

With the rapid development of China’s economy and the continuous innovation of construction industry,high-rise and super high-rise buildings are rising astonishingly.Because the use of cranes adapts to the needs of construction and development,more and more attention has been paid from managers and users of the cranes.In general,the safety situation of the construction in China is relatively stable,but a significant number of serious accidents of old cranes are happening every yearn causing immeasurable loss of economic property to the country and the people both.As for the reason of these accidents,in addition to the operator’s illegal operation,the complexity of the work task for large lifting machinery and the bad working environment is nonnegligible.All these facts make lifting machinery suffer from high cycle fatigue,material aging,corrosion and so on,which greatly shortens their service life.As mentioned in Professor Xu Hao’s "fatigue strength",more than 80%of mechanical fracture accidents are caused by metal fatigue.This paper introduces and summarizes the structure health monitoring and control management system both at home and abroad.By studying the monitoring experience of the heavy machinery and their actual working conditions at the field,this paper develops a set of structural health monitoring system based on industrial embedded system,which can be applied to monitoring the structural health of old lifting machinery.At the same time,this system has the characteristics of time monitoring,long term stability and safe operation.Moreover the system can be programmed with structural stress warning and fatigue life algorithm,providing reference for the calculation of residual life of cranes.The main contents and innovations of this paper include the following points:1.Research and develop a set of structural safety monitoring system which can be applied to large bridge cranes.The rated weight of lifting test does not need anymore at the field,because of its real-time monitoring,real-time analysis and real-time evaluation of the cumulative health of the structure.2.The simplified model of bridge cranes is established by monitoring the actual parameters of bridge cranes at the field.The elastic mechanics calculation and finite element calculation software are used to analyze the working performance to find out key points of the bridge crane for selecting the placement scheme of sensors.3.Combined the actual characteristics of bridge cranes at the field with the result of the finite element analysis,the selection and installation scheme of the sensor are studied.A set of comprehensive data acquisition card suitable for lifting machinery is developed,which can collect various data signals from cranes.4.Build the system hardware framework and network framework,and use they in the actual working conditions to test and collect.In use,the data acquisition and security alarm function are started,and the system records the life of the structure according to the data.