大柔度动臂式塔机的动静态刚度问题研究

发布时间：2018-05-17 08:51

本文选题：大柔度动臂式塔机 + 静态刚度　；参考：《哈尔滨工业大学》2012年硕士论文

【摘要】：随着高强度结构钢材的普遍使用，动臂式塔机朝着大型重载、轻质高速度方向发展的同时，其刚度却相对减少。为此，计及构件柔性变形的非线性力学分析更多地为人们所关注。本文综合考虑分析了多种因素对动臂式塔机动静态刚度的影响，基于非线性理论，分别获得了计算大柔度动臂式塔机静态刚度和动态刚度的高精度、便捷、实用表达式，并给出了两者相互关系式。充分考虑了格构式构件腹杆的影响，建立动臂式塔机的实腹等效模型。在多种复杂载荷作用下，基于非线性理论建立柔性动臂式塔机侧向位移分析的力学模型，推导出塔身端部侧向位移精确解析表达式。在精确解析表达式基础上，给出便于工程应用习惯的侧向位移实用便捷算式及其挠度放大系数和计算长度系数的表达式。对计算长度系数进行分析，得出在起重力矩一定时，侧向位移和挠度放大系数分别随吊臂仰角增加而增加的规律。分析了动臂式塔机自重及吊臂对塔机静态刚度计算结果的影响，明确了自重及吊臂在静态刚度计算分析中的重要性。根据动能等效原则，建立了动臂式塔机平面内点头频率的单自由度模型，大大降低了计算量，提高了计算效率。与传统的做法相比，塔身等效时考虑了腹杆影响，，并考虑了轴力对塔身刚度的削弱，计入挠度放大系数，提高了模型的计算精度。建立了动臂式塔机动静态刚度的之间相互关系式。通过典型动臂式塔机实例计算分析表明，采用本文中的公式计算动臂式塔机静态刚度和动态刚度的结果与通用有限元软件ANSYS的计算结果基本吻合，体现了本文方法的精确性，符合工程及科研的计算分析要求。本文的结果可为起重机设计规范中关于动臂式塔机动静态刚度的计算及对大柔度动臂式塔机力学计算分析提供理论依据。
[Abstract]:With the widespread use of high strength structural steel, the stiffness of the movable arm tower crane is relatively reduced while it is developed towards the direction of heavy load and light weight and high speed. For this reason, nonlinear mechanical analysis of flexible deformation of members has attracted more and more attention. In this paper, the influence of many factors on the dynamic and static stiffness of the movable arm tower crane is analyzed synthetically. Based on the nonlinear theory, the high precision, convenient and practical expressions for calculating the static and dynamic stiffness of the movable arm tower crane with large flexibility are obtained, respectively. The relationship between them is given. The full web equivalent model of the movable arm tower crane is established by considering the influence of the web bar of the latticed member. Based on nonlinear theory, a mechanical model for lateral displacement analysis of flexible movable arm tower crane is established under various complex loads, and an accurate analytical expression of lateral displacement at the end of tower body is derived. On the basis of the exact analytical expression, the practical and convenient formula of lateral displacement and the expressions of the deflection magnification factor and the calculating length coefficient are given, which are convenient for engineering application. Based on the analysis of the calculated length coefficient, the law that the lateral displacement and deflection magnification coefficient increase with the elevation angle of the boom is obtained when the lifting moment is fixed. The influence of dead weight and boom on the calculation results of static stiffness of tower crane is analyzed, and the importance of dead weight and boom in static stiffness calculation is clarified. According to the principle of kinetic energy equivalence, a single degree of freedom model of nodding frequency in the plane of a movable arm tower crane is established, which greatly reduces the calculation amount and improves the calculation efficiency. Compared with the traditional method, the web member is considered when the tower body is equivalent, and the axial force is considered to weaken the stiffness of the tower body, and the deflection magnification factor is taken into account to improve the calculation accuracy of the model. The relationship between the dynamic and static stiffness of the movable arm tower crane is established. Through the calculation and analysis of a typical movable arm tower crane, it is shown that the results of static and dynamic stiffness calculated by the formula in this paper are in good agreement with those of the general finite element software ANSYS, which reflects the accuracy of the method in this paper. Meet the requirements of calculation and analysis of engineering and scientific research. The results of this paper can provide a theoretical basis for the calculation of the dynamic and static stiffness of the crane in the design code of the crane and for the mechanical calculation and analysis of the movable boom tower crane with large flexibility.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH213.3

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