Overall Fracture Characteristics Of The Spar Structure Analysis And Research

Large-scale holistic Integration structures replace the traditional riveted combined structures is a trendy in aircraft structure research, the integral structure have some advantage of good supporting ability, low weight, few place of stress concentration and potential fatigue crack source, simple machining technology. But it is well known that the integral structure have some deficiency , for example, the disrepair safety character of this kind of structure is weak because of lack of the rivet which is the "natural" Crack Arrested component, that is, the anti-fracture ability of the integral structure may be lower than the riveted structure. Because of this reason, the fracture character of integral structure became the new attention problem in the field of engineering, especially the aviation engineering.From the damage tolerance design of practical Integral wing beam structure, the anti-fracture ability of wing beam structure was researched, the stress and cracking mode of Integral wing beam uncracked structure were analyzed using the FEM software ANSYS, maximum pull rule, the path of crack growth was analyzed, using finite element direct displacement method, the SIF of crack tip when crack propagate along the varied path, the effects of varied parameters of the stringer, such as: the width, length, position, having frame, without frame etc on SIF was researched.Through a lot of numerical calculations, the stress intension curves were provided and can be practically used, the analysis and conclusion can help the damage tolerance design of aircraft integral wing beam structure.