Lifting Performance Contrastive Research Of Large Margin Flat-top Tower Crane Boom

Tower crane is one kind of elevator machinery that is widely used in high-rise building, power station construction, water conservancy construction and shipbuilding etc. Boom is an important structure of tower crane, so its design directly affects the lifting performance. So far, flat-top tower crane mostly applies the structure of positive triangular section whereas application of inverted triangular section is fewer. Besides, there is no research on the contrast of these two booms’ lifting performances. This paper is mainly about flat-top tower crane. In this paper, two kinds of boom with different section shapes are discussed, to contrast the performances and look for respective application. The main work is as follows:(1) Design of boom with inverted triangular section. The boom of XGTL1200 with triangular section is selected to be the research object. On the basis of boom with positive triangular section, boom with inverted triangular section is designed, which includes the design of boom length, boom section and main chord etc. In the design process, the same weight of two booms, the same length of same number sections and the same section sizes are ensured.(2) Calculation and analysis of boom with inverted triangular section. The finite element model of boom with inverted triangular section is established with ANSYS, and the rationality of the design is analyzed from strength, stiffness, stability and mode. Considering that the bottom chord could produce stress and deformation of thin plate under wheel load, local stability, strength and stiffness is analyzed.(3) Design of derricking trolley of boom with inverted triangular section. Under the condition of large derricking, the weight of trolley is very significant to the lifting performance of boom. In this paper, Derricking trolley of boom with inverted triangular section is designed and weight parameters of derricking trolleys are contrasted under two different boom section shapes, which are used in the contrast of lifting performances. Concluding from the analysis, when the section shape is positive triangle, the weight of derricking trolley is 2t. When the section shape is inverted triangle, the weight is 1.32t.(4) Contrast of two booms with positive and inverted triangular sections. This paper focuses on the contrast of rated lifting weights when boom works on the maximum derricking with boom length as 40m,50m,60m,70m,80m. Concluding from the analysis, when the boom length is 40m,50m or 60m, the lifting performance of positive triangular section is better. When the boom length is 70m or 80m, the lifting performance of inverted triangular section is better. In addition, stiffness and stability of two different booms are contrasted under five boom lengths with loads to be equal. The advantages and disadvantages of stiffness and stability are analyzed.