Nonlinear Analysis Research And Application For Boom System Based On Finite Element Method

As boom system is the main structure to bear weight of crawler crane, its design and manufacture's qualities are important to the security of whole crane. For the long boom system of large-scale crawler crane, the boom is flexible and bearing the moment and axial force simultaneously, which results in large displacement and falls into nonlinearity. The auxiliary bracing, which is needed on this occation to improve boom's strainedcondition, makes force analysis harder. This thesis is to study nonlinear analysis mothod of boom system, and apply it to long boom system's analysis and auxiliary bracing's design, then get the rules of this boom system for practical design.Based on the geometrical nonlinear FEA theory, on the steady-function and convected coordinate formulation method, two geometrical nonlinearity which are large displacement and beem-column effect are considered. This paper presents simplified finite element model and boundary condition simulated method, codes boom system nonlinear analysis FEA program, and proves that it is not allowed to ignore the nonlinear effect of boom system. An implement method of boom system nonlinear analysis based on ANSYS is researched, and it demonstrates the feasibility of the program and its method by computing and contrasting. Furthermore, this paper applies the program to the design of auxiliary bracing, gives an example of 450t crawler crane which was developed from Dalian University of Technology and Xuzhou Heavy Machinery Co., Ltd., studies the nonlinear effects of auxiliary bracing calculation, and analyzes the design parameters of auxiliary bracing included length and fixing position. Finally, a compensated auxiliary bracing is provided, and the author confirms its validity.