Structural Analysis And Optimization On The Operated Traverse Mechanisms Of Large Building Maintenance Unit

Building maintenance unit(BMU)as the special non-standard equipment working on the higher levels,has become the important mechanical equipment to maintain and clean the external wall of high-rise and super high-rise building.With the development of the building of special-shaped wall,in order to achieve the purpose of expanding the scope of operation and to meet the higher operational requirements,the large building maintenance unit with more than 30 m jib has gradually developed.The typical telescopic arm building maintenance unit suspension rig on twin roof track gradually become the mainstream models.Operated traverse mechanism is the support basis component and the growth of telescopic jib section and the telescopic arm length may result in a change in the quality of the whole machine and the gravity center and bring operated traverse mechanisms adversely effects.Operated traverse mechanisms directly affect performance and security of the whole machine.The structure failure may cause serious accidents and consequences.So building maintenance unit maximization put forward higher requirements to the operation ability and carrying capacity of operated traverse mechanism.First of all,in this thesis,a three-dimensional model of building maintenance unit model was established by using three-dimensional modeling software SolidWorks.The assembly model was transformed into the system dynamics simulation Adams software and established a rigid virtual prototype model for building maintenance unit.According to the complete working process,the dynamic simulation analysis obtained the device characteristics and dynamic parameters of movement,such as speed,acceleration and the wheel/rail contact force.Dangerous work position was found and the result made the preparations and provided support data to the operated traverse mechanisms structure element analysis and optimization.Operated traverse mechanism includes two parts,frame structure and bearing wheel.Bearing wheel was analyzed elastic contact between wheel and rail by using Hertz contact theory and finite element method.Comparing the analysis results of two methods,the finite element method for the analysis of elastic contact required less qualification,and the consequence of high precision is much more tallied with the actual contact condition.Bearing wheel was analyzed elastoplastic contact by using finite element analysis method,got bearing wheel has reached the material yield limit comparing with the elastic contact analysis results,and the material of wheel and rail shows better carrying capacity.The building maintenance unit whole machine finite element model was established by using the APDL parametric modeling method based on ANSYS software platform.Stress and displacement were obtained by mechanics analysis.The maximum stress appeared in the frame structure vertical shaft of operated traverse mechanism and the stability of the whole machine was obtained by buckling analysis.The weak position of the operated traverse mechanism structure from above analysis result provided the convincing basis for structural optimization and amelioration.Finally.lightweight technical approach was applied for bearing wheel and based on structural improvement to improve the frame structure by using ANSYS optimization module,and analyzed the optimal scheme to verify the optimization rationality.At present,the large building maintenance unit is still in early phases of development,related research is less on operated traverse mechanism.In this thesis,based on contact analysis of bearing wheels and mechanical property analysis of frame structure for building maintenance unit,the optimization of the structure provided reference and foundation for the the large building maintenance unit and laid the foundation for the development of technology.