NEW APPROACH FOR AN INSPECTIONS PROGRAM AND USE OF C-FACTOR MODEL FOR STRESS ANALYSIS OF COMPOSITE COMPONENT STRUCTURE
Konstantin Nechval, Rafał Chatys, Igor Petukhov, Alexander Bain
Quarterly No. 3, 2024 pages 205-212
DOI: https://doi.org/10.62753/ctp.2024.07.3.3
keywords: aircraft riveted joints stress analysis, C-factor reliability
abstract A complete airplane structure is manufactured from many parts. These parts are made from sheets, extruded sections, forgings, castings, tubes, or machined shapes, which must be joined together to form subassemblies. The subassemblies must then be joined together to form larger assemblies and then finally assembled into a completed airplane. Many parts of the completed airplane must be arranged so that they can be disassembled for shipping, inspection, repair or replacement and are usually joined by bolts or rivets. In order to facilitate the assembly and disassembly of the airplane, it is desirable for such bolted or riveted connections to contain as few fasteners as possible (which is guaranteed by composite structures). Nevertheless, the impact of birds or elements during the take-off or landing (the operation) of an aircraft sometimes generates a critical dispersion of impact energy in the composite structure due to the high heterogeneity (of resin or microbubbles) of the structure. For example, a metal wing usually resists bending stresses in numerous stringers and sheet elements distributed around the periphery of the wing cross sections. The wing cannot be made as one continuous riveted assembly. The new approach to design an inspection scope and schedule based on maintenance checks brings elements of novelty. Although the maintenance schedule can be obtained through simulation, the simulation results might not be accurate enough. The obtained results provide usable analytical solutions. However, without an additional wide data-collection program, the results can serve only advisory purpose for practicians.