Study On Lightening Structure Of Long-span Double-beam Gantry Crane

With the development of economy and technology,there are more and more large-scale cranes.The use of large cranes can effectively improve the efficiency of industrial production and transportation,and work fast,release the labor cost and intensity,and realize the modernization of industrial production.For the use of long-span double-beam gantry crane,on the basis of providing convenient practicality,people began to pay attention to the operating performance and economic performance of the crane,constantly promoting the development of the crane,promote the continuous progress of social economy.In the crane structure,metal components as the main support structure,the weight of metal components generally accounted for more than 60%of the overall weight of the crane,because the crane’s weight is too large to cause the installation of the use of the same,so people are increasingly concerned about the lightweight design of large cranes.In this paper,a 16t-26m long-span double-beam gantry crane is used as the research object,and a new type of structure is adopted for lightweight design,and the designed structure is analyzed based on the finite element method.Based on a type 16 t large span double girder gantry crane,using corrugated web as supporting structure of the main girder structure design,and on this basis,adopt the design of the bridge support experience,for the support form of crane design,adopt Y support form,form a new structural form of large span double girder gantry crane.For the design of the structure form.the contrast of the original structure,modal analysis,get the design of new structure fonns in full load condition in the middle girder position the car in the first 10 order natural frequency and vibration mode diagram,the results show that juki in vertical direction when the first order modal vibration natural frequency of 3.87 Hz,satisfy the using demand of the system.System for the analysis of the static stiffness,strength,the results show that the system of static analysis compared with the original structure,the style of the new design of the crane can satisfy the requirement of the system statics,and to a certain extent,can improve the condition of stress concentration,the new structure in the form of reduced 15.9%in terms of quality,realize the goal of the light-duty design.The transient dynamic analysis of the impact on the crane in the working process shows that the vibration displacement amplitude is correlated w ith the lifting velocity,and the initial lifting velocity is inversely correlated with the tensioning time.The larger the velocity value is,the larger the displacement amplitude will be.On the basis of the new crane design to meet the needs of use,to ensure the stability of the system and the goal of lightening,the buckling analysis of the system,the results show that in different working conditions,the system’s eigenvalues are greater than 1 which shows the stability of the design structure.The local buckling analysis shows that the thickness of the trapezoidal web has an important influence on the stability of the crane.In the design process,this key parameter should be effectively studied to satisfy the stability of the system and reduce the weight of the crane.