Finite element and analytical models for load transfer calculations for structures utilizing metal and composites with large CTE differences

摘要: Large composite structures have been increasingly used in the aviation industry. In order to achieve higher fuel efficiency, use of light-weight, high-strength materials, such as carbon/epoxy, needs be fully explored. New applications materials include primary aircraft fuselages. This study dealt with thermal stresses induced a fuselage, which fuselage skin was made carbon/epoxy and fastened aluminum beams. These resulted from large coefficient expansion (CTE) difference also temperature between time assembly, 75oF actual flight condition, -65oF). around 140oF high stresses, not only fasteners but beams panels. The two main objectives are follows: • To investigate thermally feasibility isolating skins. An experimental program conducted measure strains on top surface an beam, panel loads due CTE mismatch. approach designed effects length beam stresses. analytical model developed evaluate fastener load transfer stress within aluminum/composite assemblies. Five parameters were develop calculate hybrid structures: equivalent area panel, temperatures v stiffness determined using three-dimensional finite element analysis. attempt has effect diameter, spacing, material metallic size thickness five required find so that relation could established for working engineer determine these without doing any work. Equations correlating geometric properties provided.