Reliability And Safety Analysis Of The Box Girder Of Existing Crane

With China’s rapid economic development, The crane as material handling, loading and unloading machinery products need more and more demand, however, the fracture accidents occur frequently in large-scale machinery and equipment, the cracked crane girder structure fatigue damage in these incidents is the most representative.This paper is based on the crane girder structure as the research object, comparative analysis of shell elements with unit box girder structure modeling, simulate the3-d crack fracture model. Use the MSC.FATIGUE computer software in the fatigue life of an approximation of actual operating conditions.Using the monte-carlo method, calculate reliability index calculation of box girder. The main content of this thesis include:(1) Through MATLAB sampling program generated random from the weight of the combination of box girder structure in ANSYS transient response analysis of the impact load time history and the car running load time histories, three load generation block of load cycles.(2) Comparative analysis using shell elements and unit to establish the results of the finite element model of the box girder structure, containing three-dimensional crack fracture model using the finite element software ANSYS simulation node coupled to the shell elements with the unit connected to ensure that the accuracy of calculation, and the stress intensity factor with the trend of the crack length and structure residual strength value of the crack length.(3) In order to make the results more accurate, consider the case of stress cycles below the fatigue limit the impact of the structural fatigue life, the methods used in this article is a revised material SN curve and combined with imported ANSYS results file, use forecast MSC.FATIGUE box girder fatigue life.(4) Will load and fatigue strength as a random process, considering the fatigue damage of all kinds of random factors, dynamic analysis model is put forward in order to research the crane box girder structure fatigue reliability, remaining reliability analysis method and its numerical simulation are discussed. Used in railway container freight yard.36TU container gantry crane as research object, using the monte-carlo method, box girder remaining reliability index is calculated.