| In recent years, with the rapid development of science and technology, industrialequipments have been larger and complexity, and the accidents of fatigue is increasing.At the same time, duplex stainless steel, as a new steel types that has excellentperformance, has been widely used, and much to replace the general trend of austeniticstainless steel particularly in the pipes and the shipbuilding industry. With thebackground of the project from Chongqing Science and Technology Commission whichis called the "Research on Special Shipping Welding Technology (CSTC2008AB3033)",2205duplex stainless steel welded structure fatigue crack growth rate was studied byexperimental and ANSYS finite element simulation software in this thesis. The mainpoints are as follows:First, the thesis reviews the status and trends of the duplex stainless steel weldingandcrack propagation, and an overview of the basic theory of fatigue strength of weldedstructure were introducede in detail.Secondly,â–³K,da/dN and other parameters of2205duplex stainless steel werestudied under the different stress conditions ratio. The ability to resist fatigue growthamong base metal, heat affected zone and weld metal in the structure of this duplexstainless steel welded were investigated. The sensitivity of the stress ratio in differentparts of welded components was also analyzed.Thirdly, the crack growth rate in different parts of2205duplex stainless steelwelded components were simulation analyzed by ANSYS analysis software, and thepost-processing of the simulation data were developed by PDL language included in theANSYS. After these operations, the situation of stress, strain, the length of fatigue crackand loading states in various conditions were got and saved in the form of a document.Finally, the simulation data which analysised by ANSYS software were processedby damage model theory of Yanyao Jiang and program of Forman. At the end, Thefeasibility of finite element simulation were tested and verified by the comparisonbetween the results of Experiment and simulation.Through a series of studies, finite element simulation and experiment of the studyof2205duplex stainless steel welded structure fatigue crack growth rate were consistent.Results confirmed the feasibility of the study method.. |
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