轻量化桥式起重机主梁焊缝疲劳寿命研究

发布时间：2018-01-15 10:19

本文关键词：轻量化桥式起重机主梁焊缝疲劳寿命研究　出处：《大连理工大学》2014年硕士论文　论文类型：学位论文

【摘要】：桥式起重机在国民经济的各行各业中有着广泛的应用,随着我国现代化建设发展的需要,桥式起重机的产量迅速增长。然而,我国现有的通用型桥式起重机主要技术多沿用原苏联上世纪50年代的产品结构形式,虽然经过多次改进,但与目前国际领先水平比较仍存在很大差距。轻量化桥式起重机采用了先进的结构与技术,对起重机主梁、端梁、小车架等金属结构进行优化,减轻结构重量,降低生产成本。主梁是桥式起重机的主要承载部件,轻量化技术的应用使主梁金属结构在满足强度、刚度、稳定性的前提下实现减重。轻量化主梁的疲劳强度将直接决定整机的使用寿命。桥式起重机的主梁为焊接箱形结构,主梁破坏大部分是焊接结构的疲劳破坏。因此,研究主梁焊缝疲劳寿命是桥式起重机轻量化设计的重要内容。本文基于等效结构应力焊缝疲劳分析理论,将有限元分析软件ANSYS作为获得焊缝焊趾处的节点力和弯矩的工具,利用疲劳分析软件FE-SAFE中以等效结构应力为核心技术的VERITY模块计算焊缝节点的等效结构应力和疲劳寿命,最后通过ANSYS后处理模块得到焊缝的疲劳寿命云图。针对轻量化主梁焊缝疲劳寿命问题,论文的主要工作如下： (1)研究了等效结构应力焊接疲劳分析方法,对FE-SAFE软件VERITY模块焊缝疲劳分析流程进行详细说明。 (2)对轻量化主梁进行有限元静强度分析,在主梁结构满足强度设计要求的前提下,分析主梁焊缝疲劳寿命,并对焊缝疲劳寿命的影响因素进行分析,得出各影响因素对焊缝疲劳寿命的影响规律,最后提出满足主梁抗疲劳性能的焊缝结构形式。 (3)完成主梁焊缝疲劳试验。通过主梁焊缝疲劳试验获得大量的试验数据,验证了新型起重机主梁结构的设计安全性,为轻量化桥式起重机设计基础研究积累了有效数据和设计经验。
[Abstract]:Bridge cranes are widely used in all walks of life of the national economy. With the development of modernization in China, the output of bridge cranes is increasing rapidly. The main technology of the existing bridge crane in our country mostly follows the product structure form of the former Soviet Union in -50s. Although it has been improved many times, there is still a big gap with the international leading level at present. The light weight bridge crane adopts advanced structure and technology to optimize the metal structure such as the main girder, end beam, small frame and so on, to reduce the weight of the structure. The main beam is the main bearing part of the bridge crane. The application of lightweight technology makes the main beam metal structure meet the strength and stiffness. The fatigue strength of lightweight main beam will directly determine the service life of the whole machine. The main girder of bridge crane is welded box structure. The main beam failure is mostly the fatigue failure of welded structure. Therefore, it is important to study the fatigue life of the main beam weld seam in the lightweight design of bridge crane. Based on the equivalent stress weld fatigue analysis theory, the finite element analysis software ANSYS is used as a tool to obtain the joint force and bending moment at the weld toe. The equivalent structural stress and fatigue life of weld joints are calculated by using the VERITY module with equivalent structural stress as the core technology in the fatigue analysis software FE-SAFE. Finally, the fatigue life of weld is obtained by ANSYS post-processing module. The main work of this paper is as follows: 1) the fatigue analysis method of equivalent structure stress welding is studied, and the flow of weld fatigue analysis of FE-SAFE software VERITY module is described in detail. 2) the finite element static strength analysis of lightweight main beam is carried out, and the fatigue life of weld seam of main beam is analyzed on the premise that the structure of main beam meets the requirement of strength design, and the influencing factors of fatigue life of welding seam are analyzed. The effects of various factors on the fatigue life of the weld are obtained. Finally, the weld structure which meets the fatigue resistance of the main beam is put forward. Through the fatigue test of the main beam weld, a large number of test data are obtained, which verifies the design safety of the main girder structure of the new crane. It has accumulated effective data and design experience for the basic research of lightweight bridge crane design.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TH215

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