Evaluation of residual strength of Beechcraft Bonanza spar carry-through with fatigue cracks
A front spar carry-through structure from a Beechcraft Bonanza, affected by a fatigue crack, was obtained for analysis and testing. Examination of the structure revealed a crack that was located between the huck bolts on the lower left side of the front shear panel. The first step in this project was to digitize the structure into a three dimensional CATIA model. After a detailed analysis, the maximum loads the structure would experience were identified. Utilizing the calculated load values, the stresses in the area surrounding the crack can be approximated using Finite Element Analysis (FEA). A fatigue test will then be performed on the structure and the resulting data will be used to validate the FEA model. During the fatigue test, acoustic emission transducers will be used to collect data that will help determine the critical crack length. Currently, FAA airworthiness directives state that fatigue cracks must be fixed immediately.