Finite Element And Reliability Sensitivity Analysis Of 500 Tonne Double-Girder Gantry Crane’s Main Girders

The girders, the key parts of 500 tonne double-girder gantry crane were taken as the study object in this paper. Finite element method was used to confirm the rationality of the structural design of 500 tonne double-girder gantry crane’s main girder. Reliability sensitivity analysis method was taken to find the main factors to girder structural strength. Finite element method was also applied to optimizing the girders, while controlling the main factors.Firstly, some important parameters in structure design of the crane were explained, especially the girders structure. Also, the calculation methods were presented and the parameters of the girders were ascertained.Secondly,5 typical conditions were chosen based on the actual working conditions. The model in these conditions are analyzed by ANSYS Workbench. According to the analysis results, the equivalent stress and deformation contour of 500 tonne double-girder gantry crane’s girders in 5 typical conditions were obtained. Meanwhile, the maximum equivalent stress value and deformation value of the girders were found. The static structural analysis results were proved that the primary design girders of 500 tonne gantry crane met the design requirement, while the equivalent stress was more surplus. So, the primary designed structure of girders were absolutely necessary to be optimized.Thirdly, the structural strength of girders’ reliability analysis model was constructed. Advanced FORM was chosen as the right way to analyze reliability and reliability sensitivity of the 500 tonne gantry crane’s girders. Specifically, the gravity of girders q, the flexural modulus of girders’ section w, the length of girders L, the strength of steel f and the car weight and the rated weight F were analyzed. Based on the analysis results, the main factors to girder structural strength were obtained:flexural modulus of girders’section w and main girder length L. It had a certain reference value for optimization design of the girders.Finally, controlled the thickness of girders’ fender and web plates respectively, established the finite element analysis models of these girders. By analyzing, the thickness of girders’ fender and web plates were proven to be the the main factors to girder structural strength and the advanced FORM was truly certified to be the best and practical way for reliability and reliability sensitivity analysis of the girders. Then, the optimized parameters of girders’fender and web plates were achieved. Through ANSYS Workbench, the optimized girders were analyzed. The results indicated:(1) keeping the thickness of girders’web plates unchanged, the maximum equivalent stress value was incremental with the thickness of fender reductive. (2) keeping the thickness of girders’ fender unchanged, the maximum equivalent stress value was incremental with the thickness of web plates reducing. (3) the optimized girders can meet design requirements well.In this paper, finite element method and advanced FORM have been applied to designing and analyzing the girders of 500 tonne double-girder gantry crane, which increasing the rationality and reliability of the girders, making better use of the material and helping meet the customers’ requirements. These methods have an absolute reference value for structural design of the girders.