Aluminum Alloy Friction Stir Welds Crack Stable Extension Study

Fracture mechanics is a new branch of solid mechanics which control and prevent the structure's destruction. It refer to research the stress field and strain field of a structure, and condition or rule about the crack expension. It is used in many areas, such as the aviation, astronautics, transportation, chemical industry, machinery, materials, energy sources.The Friction Stir Weld (FSW) is a new weld technology which invented in 1991s by the English welding research institute. The new welding technology can be used to weld the material,the hard Aluminum alloy ,which be weld difficulty by the old technology. It has been widespread in the industry and has a large significance in the actual project.In recent years, the Friction Stir Weld' technology about the hard Aluminum alloy AA2524-T351 (AA2524-T351) has developed very quickly and the most corresponding researchs are about the welding craft, the material's microscopic performances change,and so less about their mechanics performances and the fracture performance research ,only a few experiments. There are barely numerical analysis researchs in domestic. The scarcity of fracture performance research lag behand the development of the friction welding craft. Therefore the study about the FSW of AA2524-T351 fracture performance has important engineering significance and the academic value.The article is the study about the AA2524-T351:1. Studying experimental result about the AA2524-T351 under two kinds of FSW welding parameters and defined the new critical CTOA.2. Using FRANC2D/L to build the Arcan model of AA2524-T351 and get the useful results.3. Compare the result of FRANC2D/L to xperimental result and suggest that the Critical COD is a viable fracture parameter for the establishment of fracture criterion and the optimization of welding parameters. 4. Has completed the function about elastic and plastic analysis of FRANC2D/L. FRANC2D/L is one kind of fracture analysis software, but has not popularized in the domestic. Therefore the paper research also can advanced the widespread use about FRANC2D/L.