Composite member

Patent metadata

Field	Value
Publication number	US-2016348644-A1
Application number	US-201615166849-A
Country	US
Kind code	A1
Filing date	May 27, 2016
Priority date	May 28, 2015
Publication date	Dec 1, 2016
Grant date	—

Abstract

A composite member comprises first and second elongate composite elements. Each has a wedge shaped end with a complimentary tapered end surface. At least one of the components is formed of a stack of fibre layers impregnated in resin, with the tapered end surface being formed by each fibre layer extending longitudinally progressively further than the adjacent layer towards the thin end of the wedge at which the fibre layers have the greatest longitudinal extent. The components are joined at their tapered ends by an adhesive, and the properties of the cured composite material of the at least one component and/or the properties of the adhesive are different in the vicinity of the thin end of the wedge as compared to the rest of the tapered surface in order to reduce the stress concentrations in this region.

First claim

What is claimed is:

1 . A composite member comprising:
a first elongate composite element; and a second elongate composite element
wherein each elongate composite element comprises a wedge shaped end with a complimentary tapered end surface; at least one of the components being formed of a stack of fibre layers impregnated in resin, the tapered end surface being formed by each fibre layer extending longitudinally progressively further than the adjacent layer towards a thin end of the wedge at which the fibre layers have the greatest longitudinal extent; the components being joined at their tapered ends by an adhesive;
wherein the properties of the cured composite material of the at least one component and/or the properties of the adhesive are different in the vicinity of the thin end of the wedge as compared to the rest of the tapered surface in order to reduce the stress concentrations in this region.

2 . The composite member according to claim 1 , wherein the properties which are different may be one or more selected from the following group: fibre layer thickness, fibre/resin volume, fibre material, resin material, longitudinal spacing between fibre layers and adhesive material.

3 . The composite member according to claim 2 , wherein the different properties in the vicinity of the thin end of the wedge extend across the full longitudinal length of the composite element.

4 . The composite member according to claim 1 , wherein the different properties in the vicinity of the thin end of the wedge do not extend across the full longitudinal length of the composite element.

5 . The composite member according to claim 1 , wherein the composite member is a spar cap for use in a wind turbine blade.

6 . The composite member according to claim 5 , wherein the first elongate element is a spar cap element, the second elongate element is a connection piece joined at one end to the first element and at an opposite end to a third element which is a second spar cap element.

7 . A method of forming a composite member according to claim 1 , the method comprising applying adhesive to at least one of the tapered end surfaces, bringing the tapered end surfaces together and curing the composite material and adhesive.

Assignees

• Blade Dynamics Ltd

Inventors

• Hayden Paul Trevor
• Behmer Harald

Classifications

• B32B2260/046

  Synthetic resin · CPC title

• B32B2262/101

  Glass fibres · CPC title

• B29C66/7212

  characterised by the composition of the fibres · CPC title

• B29L2031/085

  Wind turbine blades · CPC title

• B29C66/1162

  Single bevel to bevel joints, e.g. mitre joints · CPC title