QTZ100平头式塔式起重机起重臂疲劳特性分析
发布时间：2019-02-13 20:16
【摘要】：平头式塔式起重机在安装和使用过程中的优势越来越明显，但由于其发展的历史不是很长，工况载荷对其结构因素的影响还没有得到充分的实践数据验证。目前对于平头式塔式起重机的研究还主要是通过类比的方法来进行结构强度及稳定性设计计算，而对于利用疲劳特性方法并综合载荷、材料、焊接结构等许多不确定因素的影响来分析其结构寿命考虑较少。 本文以QTZ100平头式塔式起重机起重臂作为研究对象，，利用疲劳理论方法和有限元数值方法得出了起重臂弦杆与腹杆焊接处的疲劳寿命及允许的初始裂纹长度，并结合实验进行了验证。 本文的主要内容简述如下： （1）对QTZ100平头式塔式起重机起重臂弦杆与腹杆焊接处进行理论和数值计算，得出弦杆与腹杆焊接处的应力值,并通过对载荷谱的研究得出应力幅值。 （2）综合应力幅值和《起重机设计规范》（GB/T3811-2008）对于塔机的设计寿命要求并以经典疲劳理论与高周疲劳损伤理论为基础得出两种理论下允许的初始裂纹长度。 （3）将QTZ100平头式塔式起重机起重臂弦杆与腹杆焊接结构处进行简化后试制出疲劳拉伸试样，应用疲劳试验机进行疲劳特性实验，并对其实验结果进行了分析。 （4）对QTZ100平头式塔式起重机起重臂焊接结构处进行有限元建模分析，将得出的应力应变场及裂纹扩展形态与理论及实验结果进行了对比。 本文着重对焊缝的裂纹扩展寿命及扩展形态进行了研究，得出了在存在不同焊缝裂纹时的疲劳寿命和在设计寿命基础上允许的初始裂纹长度，为塔式起重机起重臂的疲劳寿命预测提供了新的研究方法，同时也为塔式起重机起重臂的疲劳寿命设计提供理论依据。
[Abstract]:The advantages of flat head tower crane in installation and use are more and more obvious, but the influence of load on its structure has not been fully verified by practical data due to the fact that the history of its development is not very long. At present, the research of flat head tower crane is mainly carried out by analogy method to design and calculate the structural strength and stability, but for the use of fatigue characteristic method and comprehensive load, material, The influence of many uncertain factors, such as welding structure, on structural life is less considered. In this paper, the fatigue life and the allowable initial crack length of the joint between the chord and the web are obtained by using the fatigue theory method and the finite element numerical method, taking the lifting arm of the QTZ100 flat head tower crane as the research object. The experimental results are verified. The main contents of this paper are summarized as follows: (1) the theoretical and numerical calculation of the joint between the chord and the web of the QTZ100 flat head tower crane is carried out, and the stress values of the joint between the chord and the web are obtained. The stress amplitude is obtained by studying the load spectrum. (2) combining the stress amplitude and the Crane Design Code (GB/T3811-2008) for the design life of the tower crane, and based on the classical fatigue theory and the high cycle fatigue damage theory, the allowable initial crack length is obtained. (3) the fatigue tensile specimen was made by simplifying the welding structure between the hoist chord and the web rod of the QTZ100 flat head tower crane, and the fatigue characteristic experiment was carried out by using the fatigue testing machine, and the experimental results were analyzed. (4) the finite element modeling and analysis of the welded structure of the lifting jib of QTZ100 flat head tower crane are carried out, and the stress and strain field and crack propagation are compared with the theoretical and experimental results. In this paper, the fatigue life and the initial crack length allowed on the basis of the design life are obtained by studying the crack propagation life and the propagation morphology of the weld seam, and the fatigue life and the initial crack length of the weld are obtained when there are different weld cracks. It provides a new research method for predicting the fatigue life of the tower crane boom, and also provides a theoretical basis for the design of the fatigue life of the tower crane boom.
【学位授予单位】：湘潭大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH213.3
本文编号：2421831
[Abstract]:The advantages of flat head tower crane in installation and use are more and more obvious, but the influence of load on its structure has not been fully verified by practical data due to the fact that the history of its development is not very long. At present, the research of flat head tower crane is mainly carried out by analogy method to design and calculate the structural strength and stability, but for the use of fatigue characteristic method and comprehensive load, material, The influence of many uncertain factors, such as welding structure, on structural life is less considered. In this paper, the fatigue life and the allowable initial crack length of the joint between the chord and the web are obtained by using the fatigue theory method and the finite element numerical method, taking the lifting arm of the QTZ100 flat head tower crane as the research object. The experimental results are verified. The main contents of this paper are summarized as follows: (1) the theoretical and numerical calculation of the joint between the chord and the web of the QTZ100 flat head tower crane is carried out, and the stress values of the joint between the chord and the web are obtained. The stress amplitude is obtained by studying the load spectrum. (2) combining the stress amplitude and the Crane Design Code (GB/T3811-2008) for the design life of the tower crane, and based on the classical fatigue theory and the high cycle fatigue damage theory, the allowable initial crack length is obtained. (3) the fatigue tensile specimen was made by simplifying the welding structure between the hoist chord and the web rod of the QTZ100 flat head tower crane, and the fatigue characteristic experiment was carried out by using the fatigue testing machine, and the experimental results were analyzed. (4) the finite element modeling and analysis of the welded structure of the lifting jib of QTZ100 flat head tower crane are carried out, and the stress and strain field and crack propagation are compared with the theoretical and experimental results. In this paper, the fatigue life and the initial crack length allowed on the basis of the design life are obtained by studying the crack propagation life and the propagation morphology of the weld seam, and the fatigue life and the initial crack length of the weld are obtained when there are different weld cracks. It provides a new research method for predicting the fatigue life of the tower crane boom, and also provides a theoretical basis for the design of the fatigue life of the tower crane boom.
【学位授予单位】：湘潭大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH213.3
【参考文献】
相关硕士学位论文 前1条
1 杨华平;QTZ100平头式塔式起重机结构安全性研究[D];湘潭大学;2011年
本文编号：2421831
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