Research On Fatigue Strength Of Arc Transitional Crane Beam Weld Based On Peak Stress Method

The traditional circular transition crane beam has been in service in China's industrial buildings for about 40 years.During this period,the problem of fatigue damage caused by the weld at the arc-transition is exposed,which seriously threatens the safety of the crane beam system.CISDI Group Co.,Ltd.has proposed a three-web circular transition crane beam for its shortcomings.So far,the fatigue performance of this type of crane beam has not been studied comprehensively,and the fatigue evaluation basis of this type of crane beam is lacking.The main purpose of this paper is to study the fatigue performance of two types of circular transition crane beam steel components in existing industrial plants.On the basis of the fatigue theory,relying on the subject “Study on fatigue assessment and reinforcement technology of existing industrial building steel structures” of the “13th Five-Year Plan” national key project,in view of the fatigue problems of the traditional circular transition crane beam and the three-web circular transition crane beam in the metallurgical workshop,the following work was carried out:Firstly,the basic theory of fatigue damage of crane beam is introduced,and the fatigue characteristics of crane beam and the method of improving fatigue performance are summarized.Based on the previous theory,the peak stress method is applied to the evaluation of fatigue strength of two types of circular transition steel crane beams.Then,the fatigue test of the scale model of the circular transition crane beam is carried out,and the fatigue failure laws of the two types of crane beams are summarized.On the other hand,the submodel technique in ABAQUS is used to calculate the equivalent peak stress of the fatigue cracking zone,and the equivalent peak stress is taken as the basic parameter.The fatigue performance of the two types of crane beams is quantitatively studied by S-N fatigue curve.In addition,combined with the experimental data and numerical simulation results for comparative analysis,the details of the cracking of the welds of two types of crane beams are compared,which provides support for the detection and reinforcement of the circular transition crane beam of industrial plants.Finally,the main plant inspection project of Weifang Special Steel Group was used to test and analyze the load spectrum of the circular transition crane beam,and the fatigue life of the two types of circular crane beams was evaluated to verify the engineering applicability of the fatigue curve.Through the above work,the engineering applicability of the peak stress method for the fatigue analysis of circular transition crane beam is verified.Compared with the traditional circular transition crane beam,the fatigue performance of the three-web circular transition crane beam is significantly improved.The work of this paper has important engineering significance for the fatigue diagnosis and treatment technology and life promotion management technology of the circular transition crane beam system.