【作者】 李艳艳；

【导师】 高媛；

【作者基本信息】 大连理工大学 ， 机械设计及理论， 2012， 硕士

【摘要】 全地面起重机在工厂、码头、建筑工地、矿山等场地有着广泛的用途。为实现起重机大起升高度和大幅度,主臂与副臂的组合方式得到了广泛应用。大起升高度和大幅度时的起重量逐渐成为衡量起重机性能的一个重要指标。起重能力是由一定臂长和幅度下的额定起重量定义的,而额定起重量又反过来影响着幅度,因此在设计过程中必须考虑臂架变形的影响。目前在起重性能的计算和变形的计算上有了一些研究,但并没有深入研究起重量对变形的影响。换而言之,在对起重性能进行确定时没有相关文献讨论起重量对变形量的影响。本文以某500t全地面起重机臂架系统为研究对象,从线性、非线性理论出发,仅针对臂架强度决定的起重性能,研究主臂工况和塔式副臂工况下不同理论对臂架变形量的影响规律。具体研究工作如下：(1)研究全地面起重机的作业工况和臂架工作原理,选取主臂工况和塔式副臂工况为研究对象,在充分了解臂架结构特点的基础上对臂架各部分进行模型简化并建立两种工况下臂架的有限元模型。对此两种工况下简化模型和复杂模型进行对比,验证本文简化模型的正确性。(2)研究有限元参数化建模思想,采用比例迭代法利用ANSYS有限元软件的APDL语言编写求解最大起重量的计算程序,实现线性、非线性理论下不同工况的循环求解。(3)用MATLAB对有限元结果进行处理,通过对不同初始变幅角、主臂臂长和塔式副臂臂长等因素的研究,得出线性、非线性理论对臂架变形的影响规律。研究结果表明,随着主臂臂长、塔臂臂长以及初始变幅角的增加,刚性、线性、非线性对变形量的影响差别越来越大。因此,在臂长较短或者臂长较长初始变幅角较小时,可用线性模型代替非线性模型,以提高计算效率。本文研究成果为同类型全地面起重机臂架系统有限元模型的简化提供借鉴,为臂架系统的设计、分析提供了参考,同时为更准确合理的计算起重性能提供依据。更多还原

【Abstract】 All-terrain crane has a wide usage in factories, docks, construction sites, mines and other fields. The combination of main boom and tower jib has been widely used for large lifting height and workable radius of the crane. The lifting weight under large lifting height and workable radius seems to be an important indicator to measure the crane. Since the normal lifting capacity is defined by the rating weight under a certain length of boom and designated workable radius, then the rating weight can influence the workable radius. Therefore, the deformation effects should be considered in design process.Some researches have been studied on the calculation of lifting capacity and deformation, whereas there is no in-depth explotation on the influence of lifting weight on the deformation. In other words, no papers discuss the lifting weight influence under the deformation when determining lifting capacity.A certain500t all-terrain crane is taken to study, based on the linear and nonlinear theories, laws of the influence of different theories on the main boom and the tower jib working conditions are all considered. Specific research works are as follows:(1) The working conditions and principles of all-terrain crane are studied, and the main-boom and the tower jib working conditions are selected out. The models of every part of the boom are simplified and the FEA models are set up with fully understanding the boom structure. A comparison is made from the simplified and the complicated model to verify the correctness of the simplification in this thesis.(2) Parameterized modeling is investigated. With APDL provided by FEA software ANSYS, a proportional iterative method is used in program to solve the maximum lifting weight, tending to realize various cycle conditions under linear and nonlinear theories.(3) MATLAB is used in processing the FEA results by researching different initial luffing angle, length of the main boom and the length of the tower jib to obtain the laws of influence of linear and nonlinear theories on deformation of the boom.The study indicates that with the increase of the length of the main boom and the tower jib and the initial luffing angle, the influence of stiffness linearity and nonlinearity on deformation grows larger. As a result, when the boom is comparatively short or the initial luffing angle is small, calculating efficiency can be improved by the replace of nonlinear model by using the linear one. The results provide a reference for simplifying the finite element model of the same type boom for all-terrain crane. This still suits for its designing and analyzing. It can be a more accurate and reasonable method for lifting capacity calculation.更多还原