| With theimprovement of requirements engineering onstruction,construction machinery has also gradually develop in the direction to the large tonnage.Truck crane construction machinery as the main product, is the development of large-tonnage:Boom growing more and performance growing more.Finite element method structural analysis as the most suitable approach for the design staff has been gradually accepted.In order to better combine calculation of the traditional method and the finite element method,in virtue the development of 500 tons and 400 tons All-terrain crane,Find truck crane-assisted finite element method of calculating the design.At the same time for large-tonnage lay the foundation for product development.500 tons and 400 tons All-terrain crane of the development process is divided into the program, the detailed calculation, performance calculation and the parameters of phase for a total of four stages, the current performance of the calculation has completed a major phase of work. Procedures for the preparation of the performance calculation. calculating the performance of the products and submit it with the factory.In accordance with the requirements of the factory, the performance of control is divided into the intensity control, stiffness control, vehicle rollover stability control, slewing control, outrigger reaction force control and force control Luffing anti-tanks. Among them, the intensity control, stiffness control and amplitude control of the performance primarily on the basis of the finite element model. Tipping vehicle stability control, power control and anti-outrigger slewing control the performance of the main design specifications in accordance with crane and crane design manual prepared formula. Are more than six kinds of control flow through the preparation of APDL in ANSYS in order to achieve.This paper highlights the performance of computational procedures in the preparation of the main problems encountered and methods: The finite element crane model simulations, analysis of types and the results of calculation procedures. In the calculation of the process, using the shell element models and beam element model to simulate the structure of a crane. Shell element model can reflect the characteristics of all the characteristics of the structure, which reflects the structure of power in the state, local stress, but the accuracy of calculation results due to mesh density and element in it the size of mesh must be moderate, relatively slow speed makes the calculation, so the use of shell element model of the main stage in the detailed calculations. Beam element model, is through the establishment of beam element, and then given the form of custom cross-section crane simulation, simulation in this manner can be a true reflection of the characteristics of the crane section. Slider through the establishment of units and sections of constraint equation simulation to connect the relationship between the crane, the crane can be a true representation of the forces. Calculation model and a relatively small number of units, so the calculation speed is very fast, which is in the calculation of program performance computing and large computing requirements.Modules for different models, namely the use of a linear static analysis and geometric analysis of large deformation. Linear static analysis is the basic method of structural analysis, mainly based on the assumption of small deformation, the calculation formula for calculating the mechanical and calculated results are very close. Little deformation of the work structure, such as the frame and table structure, more precise calculations. Analysis of large deformation geometry is a non-linear analysis, it mainly takes into account the process of loading imposed by structural deformation of the structure. Due to the characteristics and structure of forces and other factors, cranes crane is a very large deformation, especially in the case of a longer arm length. The use of large deformation analysis can be fully taken into account the structural deformation due to the additional bending moment of the impact of the crane. Through prototype test results and comparison of results found with the crane beam element model, using the geometric large deformation analysis results with test results very kiss and, in particular, is the long arm of the working conditions and the results are less than the relative error 5%. Therefore, the use of crane beam element simulation, very high reliability performance.The same structure, although the results of finite element results than the theoretical formula of high accuracy, but the calculation speed is slow, and the performance of the calculation of the volume of calculation is very large, it is necessary to improve the computing speed of the calculation method. In the calculation of the process, namely the use of linear search, the dichotomy and work to improve the status of the succession of three methods of computing speed, which makes the calculation time by a third, greatly improving the computational efficiency.As 500 tons and 400 tons All-terrain crane structure and the structure of similar products abroad, through the performance curve, we can find a better method of calculating foreign crane. If the calculated performance curve and performance curve, the trend of foreign products in line, you can view, control is reasonable, only need to adjust the control of the control standards. If the calculated performance curve, the performance of foreign products and trends in the differences that there are other foreign products control standards of performance, you need to control the content of further study. 500 tons and 400 tons All-terrain crane, the calculated performance curves of the main arm and the performance of similar products abroad is very similar curves, and the main arm + luffing jib structure is greatly different results, this may be the performance of control did not consider the reasons for the stability of the crane, crane, so further research is also necessary to determine the contents of the calculation control. |
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