Research And Development Of Digital Twin-based Intelligent Monitoring System For Bridge Girder Erection Machine

In 2016,the Ministry of Transport released the ’Medium and Long-term Railway Network Planning’ and proposed an ’eight vertical and eight horizontal’ high-speed railway network,which is expected to reach 38000 kilometers of high-speed rail in China by 2025.With the continuous acceleration of China’s high-speed railway development process,the use of highspeed railway large-tonnage bridge girder erection machine is increasingly frequent.In the process of the overall bridge girder erection machine installation and construction,it is easy to produce collision,derailment,collapse caused by insufficient strength of the components,causing serious economic losses and casualties,affecting the speed of bridge construction,and hiding safety hazards for the subsequent construction and maintenance of the bridge.In order to solve the above problems,this thesis developed an intelligent monitoring system based on digital twin,Io T and finite element analysis technology around the construction process of SLJ900/32 type mobile bridge girder erection machine.The construction process of the bridge girder erection machine was simulated and dynamically monitored,so as to improve the construction quality and reduce the construction risks.Firstly,this thesis designed intelligent monitoring system for bridge girder erection machine based on the digital twin.According to the construction process of SLJ900/32 mobile bridge girder erection machine,proposed the system design objectives,analyzed the system functional requirements,and confirmed the system technology development route,and lightened the design model,and built a high-fidelity virtual construction scene using by Unity3 D to realize the virtual construction environment of the bridge girder erection machine.Secondly,for the construction process is prone to collision interference and low visualization problem,this thesis designed and developed the bridge girder erection machine process simulation,collision detection and virtual scene roaming function modules,implemented script driven bridge erecting machine construction process simulation using by Unity 3D components and C# language,analyzed the collision interference potential of the bridge girder erection machine process,combined with Collider component to realize the construction process virtual model collision detection,and used the serial communication technology to realize the virtual-real model motion synchronization.This thesis realized the construction scene roaming and human-machine interaction during the construction process based on the HTC Vive virtual reality device.Then,for the collapse of the key parts of the bridge girder erection machine due to insufficient strength of the components problem,this thesis designed and developed the dynamic finite element analysis function module during the construction process.This thesis selected the main girder of the bridge frame as the test object,established the finite element analysis model of the main girder,analyzed the load bearing size and restraint mode of the main girder of the bridge frame under different working conditions,adopted the APDL command flow for the finite element analysis process,and realized the effective coupling between Ansys and Unity 3D software used by C# language to implement the monitoring of the mechanical performance of the key parts of the bridge frame during the construction process.Finally,this thesis developed and validated intelligent monitoring system for bridge girder erection machine based on digital twin,deployed the system test environment,established the physical model of the bridge erecting girder machine and realized the virtual-real model synchronization with the virtual digital model,selected the process of erecting 32m/900 t precast box girders for high-speed railway as a case study,and tested the SLJ900/32 mobile bridge erector process simulation,collision detection,virtual roaming and finite element analysis modules to verify the effectiveness of the system.