| The subject originates from "Technology and Industrialization of Installation and Maintenance Construction Equipment in Huge Space", which is supported by National Key Technology R&D Programe During the 11th Five-year Plan Period (Item number: 2008BAJ09B06).The project aims to develop a new spider-type aerial work platform, which will be used in the installation and maintenance of tall buildings, such as stadium, airport and so on. Wheeled chassis and spider-type outrigger are two of the most important parts of the aerial work platform.The rational selection of parameters and the structural design, the exact force analysis and calculation are very important to develop wheeled chassis.The characteristics of little weight and high stability can allow the wheeled chassis to pass through the narrow doorway and work indoors.According to the study of the foreign similar machines and the design requirments, the structural design of wheeled chassis and spider-type outrigger, the calculation of traction performance of wheeled walking device and the time of main motion have been completed.The results have revealed that the selected parameters and the technology characteristic of the wheeled chassis are rational and advanced.The designs of the wheeled chassis and outrigger are suitable for working indoors.The stability of the machine has been studided from the outrigger reaction and coefficient of working stability when the machine is working.The outrigger reaction,influenced by the elevated angle of telescopic boom,the swing angle of superstructure,the distraction angle of outrigger and the amount of telescopic,has been studided by the rated load when the basket is working at the working boundary of one and two workers area.The results have showed that,in the regular working area(θ=46°),the value of the outrigger reaction is larger than 0,which reaches the requirements of GB/T9465-2008.According to ISO16368:2003E and taking the supporting foot centerline as overturing line,the working stability of machine is studided and calculated when the basket is working at the working boundary of one and two workers area.The results have demonstrated that,in the regular working area(θ=46°),the coefficient of working stability is larger than 1.For some particular working area,where the outrigger reaction is smaller than 0 and the coefficient of working stability is less than 1, the operation of the machine can be limited by the electronic design to meet the stability.According to the results of outrigger reaction, the typical working conditions of wheeled frame and spider-type outrigger are found out.The finite element models are set up and static strength of structures are analyzed by using ANSYS software.The static stress and deformation are obtained.It can be deduced from the results that both of wheeled frame and spider-type outrigger reach the strength standards and their structural designs are reasonable.The equivalent mass and stiffness of telescopic boom are got by using the method of energy equivalent.The dynamic model is established and analyzed by transient dynamic analysis of ANSYS in two typical working conditions,including upgrade start and brake down.The dynamic response of the end of telescopic boom and frame is got.The dynamic factor of this platform is bigger than 1.11 at least by comparing the static results with the dynamic ones.Based on the results of the finite element analysis,the lower outrigger and the base of diesel engine are optimized by taking the minimum volume as the objective function and gets the optimial results at last.
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