Analysis On Static-dynamic And Fatigue Characteristics Of Metallurgical Overhead Traveling Crane

With the rapid development of steel industry, there is an increasing demand to metallurgical crane, so requirement of structure and performance have become more and more higher. Metallurgical overhead traveling crane is one of the most important equipment in steel factory, structure strength, fatigue strength and reliability of crane are reduced gradually when used frequently. Particularly, crack of metal structure of crane may occur and expand when crane is forced under action of cycled and alternated load, leading to sudden rupture of metal structure. Nowadays, China has lacked mandatory standard for service life of crane, as high cost of crane, so many cranes have run out of design life, but used also, which bring about security risk. It's significant to analysis for long service, heavy load and high frequent used crane by stress test, finite element analysis and fatigue life research.The static characteristic, dynamic characteristic (Modal analysis, Harmonic analysis, Transient analysis) and fatigue life of bridge structure of 200t-20m's crane are simulated and analyzed by ANSYS finite element software, which provide a certain reference for design, manufacture, inspection and management of crane.Distribution of stress, static stiffness and so on are known by static analysis and field test of bridge structure.Dynamic characteristic of bridge structure is analyzed, and ANSYS Parameter Design Language (APDL) of modal analysis, harmonic analysis and transient analysis have been written. Former ten natural vibration frequencies and corresponded mode shapes of bridge structure are obtained by modal analysis, dynamic stiffness of crane is checked also. Deformation of ten frequencies of bridge structure are obtained under outset dynamic excitations by harmonic analysis. Dynamic response of bridge structure when trolley frame is working in the middle are obtained by transient analysis, including time course curve of Y direction's displacement, velocity, accelerate.Fatigue life of crane is analyzed by finite element analysis, damage tolerance design and fracture mechanics. The fatigue life of middle location of under cover plate of north beam is calculated by Paris formula. Meanwhile, impact for fatigue life to parameter change of Paris formula are discussed.