重型自行式平台臂架结构动静态分析及优化

发布时间：2018-04-27 20:44

本文选题：箱型伸缩臂 + 有限元分析　；参考：《哈尔滨工业大学》2011年硕士论文

【摘要】：重型自行式平台臂架节数多、铰点多、工作位置多,受力复杂,承受弯扭剪复合载荷,并且工作环境多为高风载,高沙尘工地。本课题来源于国家十一五科技支撑计划项目《无脚手架安装作业装备技术研究与产业化开发》(编号2008BAJ09B01-3)。该重型自行式平台具有大臂长,高负载,低变形等特点,本文对其结构进行了强度、刚度、稳定性及模态等方面的研究,并对其结构进行优化,降低其自重。在对伸缩臂的伸缩原理简要说明的基础上,本文对起升角度为0°、66°、80°三种危险工况条件下的伸缩臂进行强度、刚度等静力学分析。并且针对伸缩臂轴向力承载的两种不同假设,分别建立有限元模型进行非线性静力学分析,确定了伸缩臂在工作中危险截面以及应力集中的位置,为结构优化提供宝贵参考。近些年来重型自行式平台稳定性失效逐渐成为重型自行式平台事故发生的主要原因,关于重型自行式平台箱型伸缩臂的稳定性分析越来越被学者们重视。本文在箱型伸缩臂稳定性分析时,考虑伸缩臂体与搭接滑块之间的摩擦力,通过与液压缸独立承担轴向力模型,变截面阶梯柱模型的比较,推导出由液压缸和搭接滑块处的摩擦力共同承担轴向力时箱型伸缩臂的稳定性方程。利用ansys软件,采用Lanczos法对重型自行式平台箱型伸缩臂进行模态分析,提取出前15阶固有频率及振型,并对其进行分析。为结构的动态响应分析提供了理论基础。本文建立了以箱型伸缩臂截面积为目标函数,以箱型伸缩臂刚度、强度、稳定性及结构尺寸条件为约束条件的箱型伸缩臂结构优化数学模型,借助Ansys12.0的优化程序OPT,进行分析和求解,计算后所得到的伸缩臂截面积减小了7.5%,达到了降低臂重的目的。
[Abstract]:The heavy-duty self-propelled platform has more joints, more hinges, more working positions, more complicated forces, and more high-wind loads and high sand and dust sites under the combined load of bending, torsion and shear, and the working environment is mostly high wind load and high sand dust construction site. This subject comes from the 11th Five-Year Plan of National Science and Technology support Project "Technology Research and industrialization Development of equipment without scaffolding installation" (No. 2008BAJ09B01-3). The heavy-duty self-propelled platform has the characteristics of long arm, high load, low deformation and so on. In this paper, the strength, stiffness, stability and mode of its structure are studied, and its structure is optimized to reduce its weight. On the basis of a brief explanation of the telescopic principle of the telescopic arm, the strength and stiffness of the telescopic arm under three dangerous working conditions with a lifting angle of 0 掳or 66 掳or 80 掳are analyzed in this paper. According to two different assumptions of axial load bearing of telescopic arm, the finite element model is established for nonlinear static analysis, and the position of dangerous section and stress concentration of telescopic arm in work is determined, which provides valuable reference for structural optimization. In recent years, the stability failure of heavy-duty self-propelled platform has gradually become the main cause of heavy self-propelled platform accidents, and the stability analysis of heavy-duty self-propelled platform box-type telescopic arm has been paid more and more attention by scholars. In this paper, the friction between the telescopic arm and the lap slider is taken into account in the stability analysis of the box-shaped telescopic arm. The model of axial force bearing independently with the hydraulic cylinder and the stepped column model with variable cross section are compared. The stability equation of the box telescopic arm is derived when the axial force is shared by the friction force between the hydraulic cylinder and the lap slider. By using ansys software, the modal analysis of the heavy-duty self-propelled platform box-shaped telescopic arm is carried out by using the Lanczos method. The first 15 natural frequencies and modes are extracted and analyzed. It provides a theoretical basis for the dynamic response analysis of the structure. In this paper, the optimization mathematical model of box telescopic arm structure is established, in which the cross section area of box telescopic arm is taken as the objective function, and the stiffness, strength, stability and structural dimension condition of box telescopic arm are taken as constraint conditions. By using the optimization program of Ansys12.0, the section area of the telescopic arm is reduced by 7.5%, and the weight of the arm is reduced.
【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】：2011
【分类号】：TH211.6

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