Study Of Influence On Metal Structure By Arch Beam For Gantry Crane

Gantry crane is a kind of lifting and transportation machinery which is widely used. For gantry crane, metal structure is an important part as well as the main bearing structure. For one gantry crane, the weight of metal structure can account for more than50%of the total weight. Excessive weight will increase resource consumption during production and raise lifting risk in process of assembly. It also requires more strictly on accuracy of manufacture and installation that will increase operation and maintenance costs after applying.This paper regards metal structure of general gantry crane with double girders inclined legs and cantilever as the object of research. During the traditional design of this kind of crane, an arch beam is set at the top of connection between girders and legs against girders inward together. Because of the arch beam, the whole metal structure of this kind of gantry crane had been changed into a spatial indeterminate structure. At the same time, the weight and total height increased obviously, as well as the difficulty of the installation. But whether these kinds of arch beam is necessary had rarely been researched.According to above reasons, and based on further study metal structure design methods and contents of general gantry crane, as well as confirm calculation method sand processes of traditional design, the major work for this paper is as follow:(1) The formula of internal force and displacement of metal structure for gantry crane were researched and deduced. Based on force method, by decomposing the spatial statically indeterminate problem into a few plane problems, the problems were solved separately in plane.(2) The formula of level relative displacement of rail top of gantry crane trolley with and without arch beams were deduced.(3) The feasibility of the structure without arch beams was verified. To model and calculate finite element. A QM5030gantry crane as a main design example, by analyzing stress distribution and deformation between original structure and metal structure without arch beams, the feasibility of the structure without arch beams was verified.(4) The law how the arch beams affecting the force of metal structure was studied. Changed the hoisting capacity and span separately, by contrasting the results, analyzing the different affecting situation of metal structure by arch beams.Through comparing and analyzing the calculation results, it is found that the main effect of the arch beam is to reduce the horizontal displacement of main girder, and the effect is especially remarkable while both lifting weight and span are large. But when the lifting weight and span are reducing, even the metal structure is designed without the arch beam, the stiffness and strength also can completely meet the usage requirements of the equipment. After removing arch beam, the weight of structure reduced significantly, and met the target of reducing weight directly, it had also made big sense to save resources and costs. Meanwhile, the structure which is designed without arch beam provides a valuable reference for researching of structure lightweight and innovating design for gantry crane.