CFRP加固桥式吊车金属桥架性能研究与数值模拟

发布时间：2018-06-28 22:56

本文选题：碳纤维 + 双重非线性　；参考：《山东大学》2012年硕士论文

【摘要】：桥式起重机是横架于车间、仓库和料场上空进行物料吊运的起重设备。它的两端坐落在高大的水泥柱或者金属支架上,形状似桥。桥式起重机的桥架沿铺设在两侧高架上的轨道纵向运行,可以充分利用桥架下面的空间吊运物料,不受地面设备的阻碍。它是使用范围最广、数量最多的一种起重机械。桥式起重机都是以桥形主梁的金属结构作为主要承载构件,它是整台桥式起重机的骨架。再通过起升机构、小车运行机构、大车运行机构等三个工作机构的组合运动,使起重机在固定跨度的盒形空间内完成物料搬运作业任务。因此起重机金属桥架结构必须满足强度、刚度和稳定性条件。其中强度决定了桥架的承载能力,是保证起重机安全运行的必要条件。刚度是保证桥架在规定的使用条件下不产生过大的变形,如果刚度太小,会使得桥架挠度过大,造成小车打滑或溜车的现象,进而影响小车的正常运行。而满足稳定性是保证在规定的使用条件下桥架不会失稳。本文主要研究减少因为提高桥式起重机额定载荷而引起的桥架挠度过大的问题。采用的加固材料为碳纤维材料。首先通过解析分析得到了加固钢梁界面应力的控制微分方程。然后通过数值分析的方法——几何材料双重非线性分析,得到在几种不同加固方案下,金属桥架的挠度变化以及其内部最大应力的变化。研究表明在使用碳纤维加固后,桥架的挠度和桥架内最大应力都适当减小了。而且在使用不同层数的碳纤维板加固桥架时,桥架的挠度和内部最大应力的减小幅度各不相同。其中使用三层碳纤维板的加固方案最优,桥架的挠度和内部最大应力的减小幅度最大。通过数值分析可知,加固后钢梁和胶层间的界面剪应力和剥离应力值只在梁端很短的部分较大,随着距离梁端的距离越大急剧减小随着时代的发展,生产中对起重机的起重量和安全性能提出了更高的要求。鉴于社会资源的稀缺性和工程建设的经济性,这些桥式起重机不可能因为起重量的适当提高就退役,因此对桥式吊车金属桥架进行加固可以延长这些吊车的使用寿命和确保吊车的安全工作,进而避免资源的浪费。
[Abstract]:Bridge crane is a lifting equipment for lifting materials over workshop, warehouse and material yard. Its two ends are located on tall concrete columns or metal supports, shaped like bridges. The bridge frame of the bridge crane runs longitudinally along the track laid on the two sides of the viaduct, which can make full use of the space below the bridge frame to lift and transport the material without the hindrance of the ground equipment. It is the most widely used, the largest number of lifting machinery. The bridge crane takes the metal structure of the bridge girder as the main bearing member, and it is the skeleton of the whole bridge crane. Then through the combined movement of three working mechanisms such as hoisting mechanism, trolley running mechanism and trolley running mechanism, the crane can complete the task of material handling in the fixed span box space. Therefore, the crane metal bridge structure must meet the strength, stiffness and stability conditions. The strength determines the bearing capacity of the bridge frame and is the necessary condition to ensure the safe operation of the crane. Stiffness is to ensure that the bridge frame does not produce too large deformation under the specified conditions of use. If the stiffness is too small, the deflection of the bridge frame will be too large, which will cause the skidding of the car or the phenomenon of running the car, and then affect the normal operation of the small car. To satisfy the stability is to ensure that the bridge frame will not lose stability under the prescribed conditions of use. In this paper, the problem of reducing the deflection of bridge frame caused by increasing the rated load of bridge crane is studied. The reinforcing material is carbon fiber material. First, the differential equation of stress control at the interface of strengthened steel beam is obtained by analytical analysis. Then the deflection of metal bridge and the change of maximum internal stress of metal bridge under several different reinforcement schemes are obtained by the method of numerical analysis, which is the double nonlinear analysis of geometric material. The results show that the deflection of the bridge frame and the maximum stress in the bridge frame are reduced properly after the reinforcement with carbon fiber. Moreover, the deflection and the maximum stress of the bridge frame are different when different layers of CFRP are used to reinforce the bridge frame. Among them, the reinforcement scheme with three layers of CFRP is optimal, and the maximum deflection and maximum stress of the bridge are decreased greatly. Through numerical analysis, it can be seen that the interfacial shear stress and peeling stress between the strengthened steel beam and the rubber layer are only larger in the very short part of the beam end, and decrease sharply with the increase of the distance from the beam end with the development of the times. In the production of crane lifting weight and safety performance put forward higher requirements. In view of the scarcity of social resources and the economy of engineering construction, these overhead cranes cannot be decommissioned as a result of proper lifting. Therefore, strengthening the metal bridge of bridge crane can prolong the service life of these cranes and ensure the safety of crane, thus avoiding the waste of resources.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH215

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