Application Of Limit States Design Method (LSDM) For The Design Of Steel Construction In Tower Crane

Limit states design method (LSDM) has been proposed as a parallel design method to the allowable stress method (ASM) in the standard of crane design (GB/T3811-2008). However, the new standard defines only the frame of LSDM method without detailed contents. It's different to analyze the limit load under different work states and environments. And the limit states are disparity between different materials and constructions. Additionally it's very difficult to obtain the base data in accordance with china's actual conditions. So, there are lots works to do before the true application of LSDM in the crane design. Aimed at steel construction have a big proportion weight in tower crane, this thesis focus on the application technologies of LSDM for the design of steel construction in tower crane.First, the difference and relation between LSDM and ASM are analyzed using contrast method. The concept and intension of LSDM are defined. And the operational design process of LSDM is presented in detail aimed at application in crane steel construction.Second, calculation methods on load and load combination are analyzed in detail because that load is the design base of steel construction in tower carne and it determines the calculation accuracy. A series of coefficients and tables are presented related with load including load and motive force coefficients, load combination tables. Additional, these coefficients of strength, resistance and sub-item load are tabled in order to calculate the limit stress of construction materials.Third, the principles are concluded about how to apply the LSDM for tower crane. And the calculation formulas of strength, rigidity and stability are listed which are verified by the steel construction design of crane house of TC7030. The conclusions are as followed:(1) Nonlinear analysis method should be used in the calculation of severe deformation construction because of the nonlinear relationship between load and stress.(2) LSDM should be applying on the nonlinear analysis. LSDM is realistic than ASM, so the steel construction of tower crane designed by LSDM is more safe and economic. In last, it is proposed that the develop trend of computer aided engineering (CAE) on the design of tower crane. And the problems between steel construction modeling of tower crane, finite element analysis and the CAD software are discussed combining the analysis of LSDM.