Integrity Assessment And Safety Monitoring Of Tower Crane Structural Bolt Connection

The development of the construction industry drives the growth of the number of tower cranes,and the tower crane accidents are also increasing.The failure of tower crane structural bolt connection is one of the causes of tower crane accidents.Real-time monitoring and evaluation of tower crane bolt connection status is of great significance for tower crane accident prevention and control.In this paper,ANSYS is used to model and analyze the whole and local bolt connection of tower crane,and the failure development state of structural bolt connection is quantitatively analyzed.Combined with the structural integrity evaluation method,the state of bolt connection of tower crane is evaluated.The existing monitoring technology is selected,and based on the modeling analysis results,the secondary development of monitoring device is carried out to adapt to the safety monitoring of tower crane.First of all,the development status of structural integrity research is clarified.Combined with the characteristics of tower crane structural bolts,the parameters required for evaluation are summarized,and the structural reliability evaluation method,which is used to evaluate the structural integrity of bolts,is applied.Then,the failure mechanism of bolt looseness is analyzed,and the influencing factors of bolt looseness are extracted.After defining the above of influencing factors and requiring evaluation indexes of bolt looseness,ANSYS is used to model and analyze the whole tower crane and the bolt connection,and to obtain the bolt connection looseness state and failure critical conditions under different load conditions.The reliability of bolt connection is evaluated through the bolt critical conditions.Finally,considering the space and working characteristics of the tower crane,the monitoring equipment suitable for the bolt connection of the tower crane structure is optimized.According to the requirements of wide range and high precision of the deformation of the connection interface of the tower crane,the secondary development of the monitoring equipment is carried out to adapt to the bolt connection monitoring of the tower crane,and the practicability of the developed equipment is verified by experiments.Based on the developed device,the monitoring framework of tower crane bolt connection status is constructed by using the Internet of Things.The tower crane model established in this thesis simulates the development process of bolt looseness,and quantitatively evaluates the status of tower crane structural bolts.The real-time monitoring of tower crane structural bolt connection status is realized by using the Internet of Things and the developed sensor device.The results of this paper provide theoretical and practical basis for monitoring the safety status of tower crane bolt connection,and are of great significance to the safety management of tower crane structure.