Bar of composite matrix material

Patent metadata

Field	Value
Publication number	US-2016159474-A1
Application number	US-201414228557-A
Country	US
Kind code	A1
Filing date	Mar 28, 2014
Priority date	Mar 28, 2013
Publication date	Jun 9, 2016
Grant date	—

Abstract

In a rotary wing aircraft a bar ( 1 ) of composite matrix material has a longitudinal axis ( 8 ) perpendicular to a cross section with upper and lower surfaces ( 2, 3 ). At least one torsion box ( 17 ) comprises an upper and a lower layers ( 10, 21, 11, 22 ) respectively offset of a longitudinal axis ( 8 ) and of the upper and the lower surfaces ( 2, 3 ), said upper and lower layers ( 10, 21, 11, 22 ) being laterally joint, while cross sections are filled with the first group of fibers extending essentially parallel to the longitudinal axis ( 8 ).

First claim

What is claimed is:

1 . A bar of composite matrix material, the bar being for joining a rotor blade of a rotor to a hingeless rotary hub assembly of a rotary wing aircraft, said bar having a longitudinal axis perpendicular to cross sections having upper and lower surfaces; said longitudinal axis having essentially equal distances from said upper and lower surfaces and said cross sections joining the rotor blade to the hingeless rotary hub assembly at regions that are flexible to allow the rotor blade to undergo movements in a flapping direction, in a lead-lag direction and in a pitch angle direction; the bar of composite matrix material comprising:
a first group of fibers which extend parallel to the longitudinal axis and a second group of fibers which extend at an angle to the longitudinal axis, wherein inside the cross section at least one torsion box is provided along the longitudinal axis, each of said at least one torsion box comprising an upper and a lower layer respectively offset of the longitudinal axis and of the upper and the lower surfaces, said upper and lower layers being laterally joint, while the cross sections between the upper and the lower layer, between the upper layer and the upper surface and between the lower layer and the lower surface is filled, in direction of the longer sides of the cross section at least partly, with the first group of fibers extending essentially parallel to the longitudinal axis.

2 . The bar according to claim 1 , wherein the second group of fibers extend at an angle of more or less 45 degrees relative to the longitudinal axis.

3 . The bar according to claim 1 , wherein the torsion box is closed by centrally located unidirectional layers of the first group of fibers or by additional layers of the second group of fibers with preferable more or less 45 degrees lay-up as an U-section to connect the upper and lower layers.

4 . The bar according to claim 1 , wherein the upper and lower layers are respectively positioned away from the upper and lower surfaces, at least 5% of the local height of the cross section.

5 . The bar according to claim 1 , wherein the respective distances of the upper and lower layers from each other increase from the lateral ends towards the longitudinal axis of the cross section.

6 . The bar according to claim 1 , wherein lateral parts of the upper unidirectional layers and the lower unidirectional layers each have respectively a share of up to 50% in direction of the longer sides of the cross section.

7 . The bar according to claim 1 , wherein the bar is of the flexbeam type.

Assignees

• Airbus Helicopters Deutschland GmbH

Inventors

• Pfaller Rupert
• Wagner Wolfgang J
• Ortner Martin

Classifications

• B32B5/26

  another layer {next to it} also being fibrous or filamentary {(relative arrangement of fibres or filaments of different layers B32B5/12)} · CPC title

• B32B2603/00

  Vanes, blades, propellers, rotors with blades · CPC title

• B64C27/37

  having articulated joints · CPC title

• B32B2307/542

  Shear strength · CPC title

• B64C27/33 Primary

  having flexing arms · CPC title