Research On Fatigue Performance Of The Partial Welded Structures Of Ladle Crane’s Girder

Ladle crane is a kind of essential equipment in steelmaking factory.It is consist of plates and different section bars,which belongs to typical welding structures.The welding structure is prone to the phenomenon of welding defects and stress concentration,fatigue failure of the weld joint is the main failure form of the ladle crane.It is difficult for the traditional method of nominal stress and hot spot stress to fatigue assessment of the welding structure of the ladle crane,The equivalent structural stress method has the advantage of not sensitive to the unit size of the weld joint and the ability to effectively distinguish the stress concentration effect in different types of welding structures,it becomes an ideal method for fatigue assessment of metal structure of ladle crane.The paper to having appered fatigue cracking of 180 t ladle crane as the research object,in view of the fatigue cracks appear in the main girder web and small rib plate root of this kind of local welding structure.According to the current situation of crane crack,make the corresponding test plan.Through the field stress test,the stress level and the change law of the fatigue crack zone of the local welding structure of the main beam are obtained.To establish the finite element model of the bridge and to compare different under the condition of finite element simulation results,combined with the field test results and analysis of the main beam local welding structure of crack damage mechanism.Further research on the local stress level of the welding area by sub model technology,using the equivalent structural stress method to study the local fatigue performance of the welded structure.In view of the present situation of the fatigue performance of the existing local welded structures,several different types of welding structures are put forward,The influence of the fatigue performance of the crane girder is studied,choose the best local welding structure,it has been successfully applied to the reinforcement of the crack damage ladle crane.The work of this paper is of theoretical significance to research the fatigue performance of welding structure of different local ladle crane girder,It has guiding significance for the reinforcement and repair of the actual ladle crane,and provides reference value for the design and manufacture of new products in the future.