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For a large number of active aircraft , most of the aluminum structure , after years of flight generated a lot of damage , most of which fatigue cracks and stress corrosion cracking. In order to extend the life of damaged aircraft to ensure flight safety of aircraft , damaged components must be replaced or repaired. Since the 1980s , the foreign air force developed a new structural repair technology, which uses the aircraft composite patch glued repair damaged structures , this technology with its bonding structure , light weight, stress concentration is small, maintenance low cost and greatly extended service life , etc. got national attention , extremely rapid development , has been in a variety of military and civilian aircraft has been applied . For damaged aircraft life extension problem, we use a large number of active aircraft structural aluminum structure as the research object , using finite element analysis and experimental research on the method of combining the repair of damaged metal plate crack problem is studied . First, the use of experimental data , the James-Anderson draw on traditional methods , gives a method for determining composite repair with cracks LF21 aluminum stress intensity factor test methods ; Then, using the finite element method of composite materials with a central crack patch glued numerical analysis of the metal plate , the obtained form factor and form factor test methods comparing ; Finally, the aluminum alloy plate with a central crack , damage tolerance based on the view of the composite sheet material patch length , width, and cracked plate remaining thickness on fatigue life of the law , while the composite patch size to optimize the design , finding the best critical dimension , so that the life expectancy of the longest crack , patch works best.
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