Composite laminate and load-introduction component for a load-introduction joint

Patent metadata

Field	Value
Publication number	US-10280953-B2
Application number	US-201514877077-A
Country	US
Kind code	B2
Filing date	Oct 7, 2015
Priority date	Oct 8, 2014
Publication date	May 7, 2019
Grant date	May 7, 2019

Abstract

A composite laminate for connection to at least one attachment component in a load-introduction joint, said composite laminate comprising an opening that is adapted to receive a load-introduction component of said load-introduction joint, wherein a prefailure indication element is provided in the region of said opening, said prefailure indication element being modifiable by said load-introduction component in a prefailure mode of said load-introduction joint for indication of an impending function-affecting failure of said composite laminate. The invention is further related to a corresponding load-introduction component.

First claim

What is claimed is:

1. A composite laminate for connection to at least one attachment component in a load-introduction joint, the composite laminate comprising:
an opening extending between opposing sides of the composite laminate and defining a central axis, the opening being adapted to receive a load-introduction component of the load-introduction joint therethrough; and
a prefailure indication projection defined in and circumferentially extending along a portion of a peripheral sidewall of the opening, the prefailure indication projection having a first position and a second position, the projection being compressed or partially destructed from the first position to the second position by the load-introduction component in a prefailure mode of the load-introduction joint for indication of an impending function-affecting failure of the composite laminate,
wherein the prefailure indication projection comprises an arc-shaped projection defined between axially opposing circumferentially-extending first and second arc-shaped axial recesses that extend radially away from the central axis into the peripheral sidewall of the opening, and
wherein the prefailure indication projection extends radially toward the central axis between the first and second arc-shaped axial recesses.

2. The composite laminate according to claim 1 , wherein the prefailure indication projection is arranged diametrically opposed to a main load direction of a main load that is applicable to the composite laminate in operation.

3. The composite laminate according to claim 1 , wherein the prefailure indication projection is formed to reduce a given contact surface between the load-introduction component and the composite laminate when the prefailure indication projection is in the first position.

4. The composite laminate according to claim 1 , wherein the prefailure indication projection comprises a projection thickness that amounts to at least 50% and at most 90% of a thickness of the composite laminate adjacent to the load-introduction component when the prefailure indication projection is in the first position.

5. A composite laminate for connection to an attachment component in a load-introduction joint, the composite laminate comprising:
a through-hole opening extending between opposing sides of the composite laminate and defining a central axis, the opening being adapted to receive a load-introduction component of the load-introduction joint therethrough; and
a prefailure indication projection defined in and circumferentially extending along a portion of a peripheral sidewall of the through-hole opening, the prefailure indication projection being compressed or partially destructed from a first condition to a second condition by the load-introduction component in a prefailure mode of the load-introduction joint, providing an indication of an impending function-affecting failure of the composite laminate,
wherein the prefailure indication projection comprises an arc-shaped projection defined between axially opposing circumferentially-extending first and second arc-shaped axial recesses that extend radially away from the central axis into the peripheral sidewall of the through-hole opening, and
wherein the prefailure indication projection extends radially toward the central axis between the first and second arc-shaped axial recesses.

6. The composite laminate according to claim 5 , wherein the prefailure indication projection is arranged diametrically opposed to a main load direction of a main load that is applicable to the composite laminate in operation.

7. A composite laminate for connection to an attachment component in a load-introduction joint, the composite laminate comprising:
a through-hole opening extending between opposing sides of the composite laminate and defining a central axis, the opening being adapted to receive a load-introduction component of the load-introduction joint therethrough, the through-hole opening having a diameter; and
a prefailure indication projection defined in and circumferentially extending along a portion of a peripheral sidewall of the through-hole opening, the prefailure indication projection being compressed or partially destructed from a first condition to a second condition by the load-introduction component in a prefailure mode of the load-introduction joint, providing an indication of an impending function-affecting failure of the composite laminate,
wherein the prefailure indication projection comprises an arc-shaped projection defined between axially opposing circumferentially-extending first and second arc-shaped axial recesses that extend radially away from the central axis into the peripheral sidewall of the through-hole opening,
wherein the prefailure indication projection extends radially toward the central axis between the first and second arc-shaped axial recesses, and
wherein the prefailure indication projection defines a length extending radially into the through-hole opening in a direction substantially orthogonal to a central axis of the through-hole opening, and wherein the length is no more than 50% of the diameter of the through-hole opening.

Assignees

• Airbus Helicopters Deutschland GmbH
• Airbus Heicopters Deutschland Gmbh

Inventors

• Buesing Moritz

Classifications

• B64D2045/0085

  Devices for aircraft health monitoring, e.g. monitoring flutter or vibration · CPC title

• B64C27/48

  Root attachment to rotor head · CPC title

• B29C66/721

  Fibre-reinforced materials (B29C66/729 takes precedence) · CPC title

• B29L2031/082

  Blades, e.g. for helicopters · CPC title

• F16B31/02

  for indicating {the attainment of a particular tensile load} or limiting tensile load {(apparatus for, or method of, determining value of torque or twisting moment for tightening a nut or other member similarly stressed G01L5/24)} · CPC title