Study On Aircraft Structural Connection Of Calendar Life

The flight hours,flight takeoff landing numbers and calendar life are three indicators of active duty aircraft. Currently, three indicators of active duty aircraft are mismatched seriously. The flight hours and flight takeoff landing numbers have not arrived at the designated target when calendar life reached the rated life and it waste a lot of flight hours and flight takeoff landing numbers.The reason of this mismatch can be attributed to the imperfect methods and theory of the determination of calendar life. Therefore, research on calendar life has great values in theory development and engineering application. Life evaluation on aircraft structural connection is a major part of the life evaluation of aircraft life. Based on the completed evaluation method on calendar life of structural connection, this thesis focuses on some of the key technical issues. Specific content as follows:(1)This thesis is aimed at the typical aircraft structural connection. First, the pre-corrosion applied accelerating corrosion is made under the experimental condition, and then, the fatigue test is operated. As a result, the fatigue life in different years is got. By weighted considering C-T curve fitting method affected by a confidence interval, the C-T curve is given; moreover, through the corrosion fatigue test, flight corrosion influencing factor K is gained, which will laid a great foundation for the later calendar life evaluation.(2)The accuracy of the detail stress analysis is directly related to the analysis result of the connection life. This thesis firstly uses CATIA V5to build the3D-model and then does a three-dimensional finite-element analysis of the connection by software of ABAQUS. Thus, the stress distribution of connection will be obtained. The two examples demonstrate that using this method is much more than effective than the traditional ones as to the experimental results.(3)Based on the discussion of the traditional SSF method, this thesis has improved this method and got the key connection’s fatigue life of the aircraft.it modifies the fatigue life under the given flight strength condition, from which the calendar life and aircraft life system of the aircraft connection are got.