Bolted connection transmitting transverse forces in laminated fibrous composite structures, includes resilient filler in bolt holes elongated as a function of their distance from center and further reinforced by local layers of metal sheet

摘要

Outer openings (11, 12), i.e. those near the ends of the long row(s) of bolts, have greater width than the bolts passing through them. Thus an intermediate space (3) or clearance is left. This contains a filler with lower modulus of elasticity than the fibrous composite component (1). An Independent claim is included for the method of making the bolt opening and filling. The opening is introduced and closed-off flush with the surfaces. The matrix is injected. The tightly-fitting bolt hole is bored out centrally, in the hardened filler. Preferred features: Only the one or two central openings (10) in a row, have no intermediate space (3). The width of the space increases, with the distance of the opening from the central bolt(s). The interspaces (3) with filler are symmetrical about the center of the row. The outer openings are slot-shaped and aligned with the direction of loading (F). Slot center point spacing, increases with the distance from the row center. The fibrous composite, at the locations of joining, contains individual metal layers replacing composite layers. The number of such metal layers increases towards the center of the connection, in the loading direction. Near the outer openings, the metal layers are located near the surfaces of the composite. Bolt stiffness and/or diameter and/or modulus of elasticity rise towards the center of the joint. Filler modulus of elasticity rises from the center outwards. The filler comprises: short fibers with a matrix, a random nonwoven, or a sealant mastic. Outer openings taper conically inward on both sides. In construction, the injected filler is heated, and during injection, air is withdrawn from the closed-off opening.