Development And Application Of Tower Crane Mechanics Simulation System

Tower cranes are important construction equipment in the construction industry and mainly complete loading,unloading and transportation of cargoes by lifting,rotating and transporting operations.Dynamic loads induced by frequently starting and braking the three major mechanisms cause structure vibrations of the tower cranes and the dynamic stresses induced by the structural vibrations cause fatigue damage of the mechanical parts.A special tower crane mechanics simulation system was developed based on the structural characteristics of the tower crane and its actual working conditions by the interface technology between Visual Studio and ANSYS software.The static stresses,dynamic stresses and vibration behaviors of the tower crane structure and the responses of the maximum static stresses,maximum dynamic stresses and vibrations of the tower crane structure were simulated on the simulation system for the various working conditions.The main research contents are as follows:(1)The functional requirements of the tower crane mechanical simulation system were determined,the overall framework and system interface of the simulation system were designed,and the system development process is formulated according to the structural features and dynamic characteristics of the tower cranes,combined with the characteristics of ANSYS and Visual Studio software and related development languages.Then the APDL parameterized design language was used to establish the finite element model of the tower crane.And the key technologies such as Visual Studio and ANSYS interface technology,user interface parameter transfer technology,and simulation results display technology were used to establish mechanical simulation system of the tower cranes.Finally,the simulation system that can simulate static stress,dynamic stress and vibration characteristics was finished.(2)Static simulation of the tower crane structure was finished on the tower crane mechanics simulation system.The maximum static stress of the tower crane structure and the deflection value of the jib were obtained under various working conditions.The static strength and staticstiffness of the tower crane structure were checked according to the simulation results.The static stresses of the crane structure were carried out by mean of the static stress test.And the accuracy of the mechanical simulation system of the tower crane and the reliability of the finite element model were verified by comparing the test results with the simulation results.(3)The dynamic loads of the tower cranes were analyzed under the single working conditions and composite working conditions.The dynamic stresses and vibration characteristics of the tower crane structure were simulated on the tower crane mechanics simulation system and the maximum dynamic stresses and vibration responses of the tower body and jib were obtained during the various working conditions.The effects of parameter change such as cargo mass,transporting width,lifting speed and transporting speed on the maximum dynamic stress and vibration characteristics of the tower crane structure were also discussed.The simulations results show that the maximum dynamic stresses on the tower crane structure and the deflections,vibration periods and vibration amplitudes of the tower body and the jib become bigger with the cargo mass,the transporting width,the lifting speed,and the transporting speed.