Optimization Design Of Crane’s Main Girder Considering Fatigue Behavior At The End Segment

During the periodical inspection of the crane’s metal structure, cracks were oftenfound at the weld of the transition arc region at the end of the main girder. So, it isnecessary to consider the fatigue performance about this area in the lightweight designingof the main girder. In view of the bridge crane box girder welding structure lightweightingproblem, considering the fatigue characteristics of variable cross-section area end of thispaper proposes a lightweight design method based on the hot spot stress method.The maincontents are:In the regular inspection of bridge crane metal structure, often in the region of thegirder ends transition arc weld position found the crack, so need to consider in thelightweight design of main girder fatigue properties of the parts. In the light of the boxgirder bridge crane welded structure of lightweight problem, considering the fatiguecharacteristics of variable cross-section area end of this paper proposes a lightweightdesign method based on the hot spot stress method.First of all, in the traditional design method of crane by gm bridge crane box girderon mechanical behavior research, and in a factory production of tz22.5/5intermediatebridge crane girders for regular stress checking, found the result while meet therequirements of general constraint design, but it can be lightweight and space.Secondly, based on the hot spot stress method, in view of the main girder end fatigueproblem of variable cross-section area, its finite element simulation model is established,the calculation of the hot spots of stress concentration coefficient expression, get here ofthe hot spot stress criterion is put forward here, and in order to verify the main girder endvariable cross-section area should be considered while checking fatigue properties.Finally, on the basis of optimization theory, the minimum structure quality as thedesign goal, the static intensity, static rigidity, stability based on regular constraint, joinedthe girder end arc section of fatigue strength of the constraints, established theoptimization model of box girder structure, using the MATLAB powerful computing tools,designed the optimization procedure, by comparing the experimental results show that inthe lightweight optimization design considering end fatigue properties, the result hashigher reliability, but also make the box girder of the bridge crane weight, save the costand create the benefits.