About choice of holes sizes and layouts for fastener assembly of rotor composite blades | Mekhanika | kompozitsionnykh | materialov i konstruktsii
> Volume 24 > №3 / 2018 / Pages: 349-361

About choice of holes sizes and layouts for fastener assembly of rotor composite blades


A question of rotor composite blades intelligent design is considered in this article. Usually the layout and size ratio of aperture for fastener assembly bolts into rotor longeron blade are chosen on the basis of the constructive and technological reasons. Incidentally of course the strength and fatigue resources requirements are took into account. However, as a rule, the preference gives up to easiest decision that is simplest from the technological point of view. Meanwhile it is the stress-strain state features into this region that who determine largely strength and fatigues properties of blade on the whole. This is check out of bench test results as well as the vehicle exploitation into flight conditions. Series of finite element calculus are performed for estimation of optimal sizes and layouts of fastener assembly holes into rotor blade butt part. Nonlinear contact interaction between fastener assembly bolts and blade composite material are took into account for finite-element model. Hill’s criterion is used for estimation of stress-strain state of multilayer composite material. Incidentally the necessity are appeared of determination of preliminary estimations of strength limits for arbitrary layup multilayer material that having known monolayer characteristics. Deformation curve building algorithm for multilayer composite material is developed. Diagram data are used for estimation multilayer layup stiffness characteristics and limit linear load. Composite material stress state estimation calculus is implemented for fastener assembly regions at determined loading conditions. 45 layout and size ratio variants of aperture are considered. On the basis of the calculus results conclusion are made that actual variant of constructive solutions not optimal.