塔吊结构在风力及吊重耦合作用下的响应分析
发布时间：2018-08-09 15:35
【摘要】：随着经济和社会的发展,为适应工程施工及物流运输的需要,塔式起重机的型式朝着塔身更高、塔臂更长的方向发展,而起重量也朝着更重的目标前进。这也给塔式起重机的设计计算与安全操作带来了挑战。因塔身更高,结构受到风荷载的影响也越大,那么再按以往将风做静力考虑是不合时宜的；因塔臂更长、起重量更重,塔式起重机在服役过程中机械操作带来的冲击激励造成的影响也更剧烈。上述两类外激励均会造成结构的振动,而对于这类振动响应的分析在塔式起重机的设计与制造以及安全操作方面具有指导意义。本文以QTZ25塔式起重机为例,进行分析讨论。 在建立该塔吊模型时,本文将少自由度法与有限元法相结合以简化结构自由度数目,再利用ANSYS有限元软件建立此简化模型。并选取起升工况、卸载工况、00风工况、90°风工况、起升与0°风工况、卸载与0°风工况、起升与900风工况、卸载与900风工况进行分析。其中,对于起升与卸载工况中的冲击激励运用动载系数法,参照《起重机设计规范》(GB3811-2008)求出冲击系数进而得到冲击激励；对于风载,本文运用线性滤波法自回归技术模拟出脉动风进而得到各工况所需风载。为简便直观的比较分析结果,本文在激励施加方式与施加时间设计上采用三段式的方式,将其分为初始平稳、冲击以及振动响应三个阶段。 在分析结果时,对于起升工况与卸载工况,本文提取起重臂上8个点的位移响应来分析冲击激励对起重臂的影响；而在分析其余6种工况时,本文则采用对整体结构进行分析的方法,但为了简化工程量和提高效率,仅提取塔式起重机9个点(沿塔身6个点,顺塔臂3个点)来观察各工况下的位移响应。又应力变化对分析结构振动响应亦至关重要,而塔式起重机为各个标准节拼装而成,标准节截面的应力变化对分析塔式起重机因振动而产生安全隐患有着一定的价值。故本文提取塔吊各标准节连接处55个截面的应力时程响应进行观察。 在对选取的位移响应及应力响应进行比较分析后发现：在冲击激励作用下,起重臂上振动幅度由远到近减小,且起重臂与拉杆连接处以及起重臂与塔身连接处的应力较大。在风载作用下,沿塔身从低至高,位移振动规律一致,幅度则增大。在风载与冲击激励耦合作用下,当风向与冲击激励作用面平行时,结构的振动响应会发生突变,且起升耦合工况的幅度最大；而风向与冲击激励作用面垂直时的结果与风单独作用时一致。
[Abstract]:With the development of economy and society, in order to meet the needs of engineering construction and logistics transportation, the tower crane type develops towards the direction of higher tower body and longer tower arm, and the lifting weight also moves towards the heavier target. This also brings challenges to the design calculation and safe operation of tower crane. Because the tower is taller and the structure is more affected by the wind load, it is not appropriate to consider the wind statically again in the past; because the tower arm is longer and the lifting weight is heavier, The impact caused by mechanical operation of tower crane is more severe. Both kinds of external excitations can cause structural vibration, and the analysis of these vibration responses is of great significance in the design, manufacture and safe operation of tower cranes. This paper takes QTZ25 tower crane as an example to analyze and discuss. In order to simplify the number of degrees of freedom of the structure, the method of less degrees of freedom is combined with the finite element method when the tower crane model is established, and the simplified model is established by using ANSYS finite element software. At the same time, the lifting condition, the unloading condition and the 90 掳wind condition, the lifting and the 0 掳wind condition, the unloading and the 0 掳wind condition, the lifting and 900 wind condition, the unloading and the 900 wind condition are selected and analyzed. Among them, the dynamic load coefficient method is used to calculate the impact coefficient according to the Crane Design Code (GB3811-2008) for the impact excitation in the lifting and unloading conditions, and for the wind load, the impact coefficient can be obtained by using the dynamic load coefficient method. In this paper, the method of linear filter autoregressive is used to simulate the pulsating wind and get the required wind load. In order to compare and analyze the results easily and intuitively, this paper adopts a three-stage method in the design of excitation and application time, which is divided into three stages: initial stationary, shock and vibration response. In the analysis of the results, for lifting and unloading conditions, the displacement response of 8 points on the boom is extracted to analyze the effect of shock excitation on the boom, while the other six conditions are analyzed. In this paper, the method of analyzing the whole structure is adopted, but in order to simplify the engineering quantity and improve the efficiency, only 9 points (6 points along the tower body and 3 points along the tower arm) are extracted to observe the displacement response of the tower crane under various working conditions. The stress change is also very important to the analysis of the structural vibration response, and the tower crane is composed of each standard section, and the stress change of the standard section is of certain value to the analysis of the hidden safety problems caused by the vibration of the tower crane. In this paper, the stress response of 55 sections at the joint of standard joints of tower crane is observed. After comparing and analyzing the displacement response and stress response, it is found that the vibration amplitude of the lifting arm decreases from far to near under the impact excitation, and the stress is larger at the connection between the lifting arm and the pull rod and the connection between the lifting arm and the tower body. Under the action of wind load, the displacement vibration law is consistent and the amplitude increases along the tower body from low to high. Under the coupling of wind load and shock excitation, when the wind direction is parallel to the impact excitation surface, the vibration response of the structure will change, and the amplitude of the lifting coupling condition will be the largest. When the wind direction is perpendicular to the impact excitation surface, the results are consistent with those of the wind acting alone.
【学位授予单位】：武汉理工大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH213.3
本文编号：2174539
[Abstract]:With the development of economy and society, in order to meet the needs of engineering construction and logistics transportation, the tower crane type develops towards the direction of higher tower body and longer tower arm, and the lifting weight also moves towards the heavier target. This also brings challenges to the design calculation and safe operation of tower crane. Because the tower is taller and the structure is more affected by the wind load, it is not appropriate to consider the wind statically again in the past; because the tower arm is longer and the lifting weight is heavier, The impact caused by mechanical operation of tower crane is more severe. Both kinds of external excitations can cause structural vibration, and the analysis of these vibration responses is of great significance in the design, manufacture and safe operation of tower cranes. This paper takes QTZ25 tower crane as an example to analyze and discuss. In order to simplify the number of degrees of freedom of the structure, the method of less degrees of freedom is combined with the finite element method when the tower crane model is established, and the simplified model is established by using ANSYS finite element software. At the same time, the lifting condition, the unloading condition and the 90 掳wind condition, the lifting and the 0 掳wind condition, the unloading and the 0 掳wind condition, the lifting and 900 wind condition, the unloading and the 900 wind condition are selected and analyzed. Among them, the dynamic load coefficient method is used to calculate the impact coefficient according to the Crane Design Code (GB3811-2008) for the impact excitation in the lifting and unloading conditions, and for the wind load, the impact coefficient can be obtained by using the dynamic load coefficient method. In this paper, the method of linear filter autoregressive is used to simulate the pulsating wind and get the required wind load. In order to compare and analyze the results easily and intuitively, this paper adopts a three-stage method in the design of excitation and application time, which is divided into three stages: initial stationary, shock and vibration response. In the analysis of the results, for lifting and unloading conditions, the displacement response of 8 points on the boom is extracted to analyze the effect of shock excitation on the boom, while the other six conditions are analyzed. In this paper, the method of analyzing the whole structure is adopted, but in order to simplify the engineering quantity and improve the efficiency, only 9 points (6 points along the tower body and 3 points along the tower arm) are extracted to observe the displacement response of the tower crane under various working conditions. The stress change is also very important to the analysis of the structural vibration response, and the tower crane is composed of each standard section, and the stress change of the standard section is of certain value to the analysis of the hidden safety problems caused by the vibration of the tower crane. In this paper, the stress response of 55 sections at the joint of standard joints of tower crane is observed. After comparing and analyzing the displacement response and stress response, it is found that the vibration amplitude of the lifting arm decreases from far to near under the impact excitation, and the stress is larger at the connection between the lifting arm and the pull rod and the connection between the lifting arm and the tower body. Under the action of wind load, the displacement vibration law is consistent and the amplitude increases along the tower body from low to high. Under the coupling of wind load and shock excitation, when the wind direction is parallel to the impact excitation surface, the vibration response of the structure will change, and the amplitude of the lifting coupling condition will be the largest. When the wind direction is perpendicular to the impact excitation surface, the results are consistent with those of the wind acting alone.
【学位授予单位】：武汉理工大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH213.3
【参考文献】
相关期刊论文 前7条
1 尹强;陈世教;冀满忠;;基于ANSYS的塔式起重机结构模态分析[J];重庆建筑大学学报;2005年06期
2 陆念力,夏拥军,剑明思;塔式起重机结构动态分析的两种有限元模型及比较[J];建筑机械;2002年11期
3 夏拥军,陆念力,罗冰;关于水平臂式塔机起升动载系数φ_2的一点讨论[J];工程机械;2005年01期
4 程文明,王金诺;起重机的动态分析方法[J];起重运输机械;2002年02期
5 龙沂,张明勤,李全民,林榕;塔式起重机动态特性研究的现状与发展[J];建筑机械;1998年10期
6 王之宏;风荷载的模拟研究[J];建筑结构学报;1994年01期
7 黄珊秋;QTZ80型塔式起重机的振动分析[J];起重运输机械;2000年07期
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