【作者】 牛坤；

【导师】 陆念力；

【作者基本信息】 哈尔滨工业大学 ， 机械设计及理论， 2010， 硕士

【摘要】 随着工程建设发展的需要,塔机日益向着高耸化方向发展,采用液压顶升形式进行安装拆卸的自升式塔机得到广泛应用,使顶升作业安全性问题日显突出。塔机顶升工况是需要人为参与的高空作业,鉴于特殊的工作需要,此时结构并不稳定,受力情况极为复杂,具有一定的特殊性。如何确保顶升作业安全进行,成为实际工程中的难点。到目前为止,无论是国内外规范,还是专业教科书中,对顶升工况结构受力情况的分析及合理的参数调整、风载的影响均无明确说法,通常设计制造者根据经验和简单的计算分析,使上部结构对油缸支承点平衡进行顶升。面对复杂的顶升结构受力情况,对安全顶升给出一个可以参考的理论指导和工程实用的、有效的方法,本文力图在这方面做些许有益贡献。顶升套架是顶升工况的关键受力结构,本文根据塔机顶升工况的工作特点,建立塔机顶升工况系统模型,分析套架受力的各影响因素。采用力学原理,分析上部载荷变化对受力滚轮及轮压的影响。确定结构受力最佳时的合理轮压分配原则。以动臂式塔机为例,列写以影响轮压的各因素为变化参数的轮压函数式。通过合理分配轮压,提出塔机的顶升策略,以达到使顶升工况结构受力最佳的目的。以轮压函数式为基础,分析得到最佳顶升吊臂角度。鉴于各塔机不同的工作要求,结构设计各具特殊性,某些动臂式塔机仅通过调整吊臂角度并不能达到理想的轮压平衡状态。对于此种情况,分析推导满足应力变形要求的、所能达到的相对较优状态。结合塔机配重设置一般要求,分析满足顶升最佳受力情况的合理配重。另外,对在加载合适调整吊重以求上部结构重心位置合理的方法进行了分析研究。建立多个不同幅度下顶升及上部结构完整的有限元模型,计算分析顶升工况结构受力变形情况,验证了本文计算的正确性和有效性,以便实际工程中参考和应用。同时,采用有限元软件计算分析侧向风载作用的危险顶升工况,并将各幅度下的计算结果与常规状态下顶升工况进行比较,分析侧向风载对结构受力变形等方面的影响。本文为塔机安全顶升提供了几种顶升策略与参数调整方法,并用实例进行了验证,供实际工程中使用和借鉴。更多还原

【Abstract】 With the demand of the engineering construction development, the development of increasingly towards high-rise towers, hydraulic jacking system is widely used for self-climbing tower crane building and disassembly, the problem about self-climbing safety made more obvious each day. Self-climbing is a task which needs people’s operating in the altitude, as a result of the specialization of the task, the lattice structure is not steady at the moment, the situation of the force is very complex and not in common as the others. How to make sure the safty of self-climbing operating, becomes a big problem of engineering. Until now, either in domestic and international norms, or professional textbooks, there was no clear argument about the how to analyse the force and deformation situation of self-climbing task or optimize the correlative parameters. Neither nor the effect of wind to the strucure. Generally, the fabricant accommodates center of gravity of the whole struture to the hydro cylinder bearing point on the self-climbing frame, bases on experience and simple caculation. Faced with the complex self-climbing structure force situation, giving a reference to the theoretical guidance and practical engineering, and effective method, is the purpose of this thesis. This thesis seeks to do a little useful contribution in this respect.Self-climbing frame is pivotal struture in lifting task. Bases on the peculiarity of the lifting work, this thesis establish the self-climbing system model, analyze the influencing complication to the struture. With the exoterica dynam principle, this thesis analyzes the center of gravity of the upside struture, which determines the functionary guide wheels and their pressure. This thesis also makes sure the admeasure priciple of guide wheels, when the force situation of the structure is oriental. Taking luffing-jib tower crane as example, this thesis lists the function of the guide wheels, which contains influential complication as variables.In order to maximize the self-climbing structure force situation, gives out some reasonable policies for tower crane in the method of lifting admeasuring the pressure of the wheels. Based on the wheels funcion, analyse and find the optimal luffing-jib angle for the lifting task. As the different operating requirement of tower cranes, the structure design is not the same, it is difficult to satisfy the need of optimal lifting state only in the method of admeasure the luffing-jib angle for some cranes. To deal with this kind of problem, analyse and deduce the comparatively optimal lifting state, which satisfies the condition of force and deformation attainability. Combining with the common design principle for the counterbalance of tower crane, analyse and find the reasonable counterbalance which make the self-climbing structure in the green wood. Otherwise, for the sake of logical center of gravity position of the upside structure, this thesis also considers the method of carrying load on the luffing-jib, and makes a brief analysis.In order to caculating and analysing the situation of force and deformation for lifting task, this thesis builds up several finite element models based on whole self-climbing and upside structure in several different ranges, and verify the correctness and validity of the calculation, so it can be referenced to the actual projects and applications. With the use of finite element analysis software caculate and analyse the dangerous lifting task with the effect of lateral wind, compare and analyse the result with normal lifting task in different ranges, analyse the effect of lateral wind to the structure deformation ,force and otherwise.This thesis gives out several effective lifting strategy for tower crane’s self-climbing safety, together with some method of parameter optimization. It verifies its correctness in the use of example, for the use and reference in the engineering.更多还原