Structural Analysis And Optimization Of Telescopic Ladder System For TD60 Fire Truck

The ladder fire truck is a special vehicle used by firefighters for fire fighting and personnel rescue of high-rise buildings.It is equipped with telescopic ladder frames,hydraulic systems,lifting platforms and fire extinguishing systems.The telescopic ladder system composed of turntable,bracket and a sleeve telescopic system consisting of a multisection U-shaped truss arm,and each of the ladder frame can realize the overall proportional telescopic linkage through the wire rope synchronous stretching system.The ladder system is the main load-bearing and force-bearing component,which plays a decisive role in the performance of the fire truck.This paper takes the telescopic ladder system of the ladder fire truck as the research object,and uses APDL language of ANSYS finite element analysis software to build the parametric finite element model of the whole structure of the system,and realizes the static and dynamic performance analysis of the ladder.The stress test experiments under the typical working conditions are carried out.The test results were consistent with the results of finite element analysis,which verified the correctness of the developed finite element model.According to the analysis results,the bracket structure of the telescopic ladder system and the part of the first ladder connected to it with greater stress are improved to reduce the stress concentration.The optimized design module of ANSYS is adopted to reduce the mass of the turntable as the objective function,and the geometrical parameters of the section are used as the design variables.The strength of the turntable and the overall stiffness as constraints,and the weight reduction structure of the turntable structure is optimized.The modal analysis of the overall ladder system is carried out to obtain the natural frequency and vibration mode of the ladder frame.The dynamic response analysis of the whole ladder frame under wind load is carried out,and the maximum deviation of the ladder top working platform under the wind load is obtained.The analysis results show that the improved ladder frame structure meets the design requirements of overall stiffness and strength of each component,and the optimized design scheme has been applied to actual products.