Dynamic Analysis And Optimized Design Of Crawler Spider Aerial Working Platform Chassis

Building on National Key Technology R&D Program During the 11th Five-year Plan Period, "the Technology and Industrialization of Installation and Maintenance Construction Equipment in Huge Space" (No:2008BAJ09B06), A new crawler spider style aerial working platform is developed. Instead of a universal automobile chassis, the platform is equipped with a special crawler chassis and the limitation that a car-carrying platform can only work on outdoor hardened road can be overcome.By digesting and absorbing the strongpoint of the chassis of advanced aerial working platform both at home and abroad, the crawler chassis of the aerial working platform is designed preliminarily. According to related standards, the reaction force of outrigger and stability coefficient are analyzed and calculated to obtain the force and dangerous working conditions of frame and outriggers. The variation curves of the stability coefficient and the forces loaded on outriggers and cylinders are obtained by a program coded in MATLAB. The stability and security of the whole equipment are assessed. The results have showed that,in the working boundary of one and two workers area,the value of the outrigger reaction is larger than 0,the coefficient of working stability is larger than 1,which meet the requirements of the working stability of the machine.A static finite element models for frame and outriggers are made to analyze their deformations and stresses distribution under typical working conditions. Based on energy principle, the formulas for calculating equivalent mass of jib and load are derived. A transient dynamic finite element models for the platform in the process of luffing is established by replacing jib and load with the corresponding equivalent mass, and the transient responses of the frame are achieved. The static and dynamic analysis show that the frame and outriggers meet the requirements of design.The structural parameters of the frame and the spider style outriggers are optimized on the premise of meeting all requirements in work. The weights of the frame and outriggers are reduced and the strained conditions are improved. A·crawler chassis with high efficiency, strong adaptability, and satisfying the requirements on strength and stability are designed for the aerial platform finally. In addition, a complete procedure including preliminary design, dynamic analysis and optimum design is put forward to improve the dynamic properties of mechanical structure.