岸边集装箱桥式起重机载荷谱与剩余寿命研究

发布时间：2018-11-19 17:24

【摘要】：金属结构的疲劳问题是工程机械研究领域永久的热点问题。疲劳破坏问题的发生大多具有突发性，这使得疲劳破坏总是带来毁灭性的灾难，如整机坍塌事故以及因此引发的人员伤亡。如何合理地控制或减少疲劳破坏的发生显得十分的必要。岸边集装箱桥式起重机在各港口都普遍存在，它是工作比较频繁的机械设备。岸边集装箱桥式起重机工作的特点是运行小车以重载高速往返运行在起重机的前后大梁上，且伴随着集装箱的起升、下降及运行机构的起动、制动等复杂的运动过程。因此，金属结构的受力状况是随机变化。对这种经常承受交变载荷且工作繁忙程度很高的岸边集装箱桥式起重机进行疲劳载荷谱及剩余寿命的研究是非常有必要的。本文基于国内外相关领域的研究成果和疲劳理论基础知识，结合岸边集装箱桥式起重机的结构特性及工作特点，确定其疲劳类型为高周疲劳，选用名义应力法对其进行剩余寿命的估算。本文的主要研究内容及结论如下：（1）查阅有关结构疲劳及载荷谱的研究文献，总结和分析该领域研究的现状及不足，介绍疲劳相关理论。（2）根据岸边集装箱桥式起重机金属结构的实际受力特点，结合相关的检测规范及其发生破坏的历史记录情况，选取疲劳测点；然后对测点应力进行实际动态采样，将采样数据与有限元分析获得的自重下的结构静应力进行叠加以获得完整的应力数据，用于载荷谱的编制。（3）将应力数据经过相关的数据预处理及雨流计数进行循环计数统计，对统计的计数结果展开幅值频次及幅值概率分布的研究，编制起重机结构的疲劳载荷谱。因为动态采样时间比较短，本文基于疲劳载荷谱理论对实测的载荷频次进行了外推，得到了结构在全寿命期内的载荷谱。（4）本文依据起重机设计规范确定起重机结构件的S N曲线，根据起重机的实际工作状况，选用修正的线性累积损伤理论合理地估算了岸边集装箱桥式起重机的疲劳剩余寿命，，应用VB编程实现剩余寿命估算的可视化过程。
[Abstract]:The fatigue problem of metal structures is a permanent hot issue in the field of construction machinery research. The occurrence of fatigue damage is mostly sudden, which makes fatigue damage always bring devastating disasters, such as machine collapse accident and the resulting casualties. How to reasonably control or reduce the occurrence of fatigue damage is very necessary. Quayside container bridge crane is widely used in all ports. The working characteristic of quayside container bridge crane is that the trolley runs on the front and rear girders of the crane with heavy load and high speed, and accompanied by the lifting and dropping of the container, the starting and braking of the running mechanism, and so on. Therefore, the stress condition of metal structure is random change. It is necessary to study the fatigue load spectrum and residual life of this kind of quayside container bridge crane which is often subjected to alternating load and has a high degree of busy work. In this paper, based on the research results and fatigue theory of related fields at home and abroad, combined with the structural characteristics and working characteristics of container crane, the fatigue type is determined as high cycle fatigue. Nominal stress method is used to estimate its residual life. The main contents and conclusions of this paper are as follows: (1) referring to the research literature on fatigue and load spectrum of structures, summarizing and analyzing the present situation and deficiency of the research in this field, and introducing the theory of fatigue. (2) according to the actual stress characteristics of the metal structure of the container crane, combined with the relevant testing code and the history record of the damage, the fatigue test points are selected; Then the measured point stress is sampled dynamically, and the static stress of the structure under the weight obtained by the finite element analysis is superposed to obtain the complete stress data, which can be used to compile the load spectrum. (3) the stress data are preprocessed by the relevant data and the rain flow counting is carried out. The amplitude frequency and amplitude probability distribution of the counting results are studied, and the fatigue load spectrum of the crane structure is compiled. Because the dynamic sampling time is relatively short, this paper extrapolates the measured load frequency based on the fatigue load spectrum theory, and obtains the load spectrum of the structure in the whole life cycle. (4) according to the crane design specification, the S-N curve of crane structure is determined in this paper, and according to the actual working condition of crane, The modified linear cumulative damage theory is used to estimate the fatigue residual life of quayside container bridge crane reasonably, and the visual process of residual life estimation is realized by VB programming.
【学位授予单位】：武汉理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U653.921

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