Quasi-UD glass fibre NCF composites for wind energy applications: a review of requirements and existing fatigue data for blade materials

Abstract

-Quasi-unidirectional glass fibre non crimp fabric composites are routinely used in wind energy applications. An important factor to consider in this type of application is the fatigue behaviour of the materials. The present paper gives an overview of the current approach to material fatigue testing and design in the wind energy industry, as well as a review of available material data for the fatigue of unidirectional glass fibre composites. Both "pure" unidirectional and quasi-unidirectional (NCF-based) materials are considered.

Influence of specimen type and reinforcement on measured tension–tension fatigue life of unidirectional GFRP laminates

“…One obvious reason for the better fatigue performance provided by the powder-bound fabric is the improved fibre alignment resulting from an absence of backing fibres and stitching. Stitching and backing bundles have been found to cause fibre undulation [5], which weakens fatigue performance [1]. The fatigue test results of this study are supported by the investigations in ref.…”

“…Unidirectional (UD) Non-Crimp Fabrics (NCFs) are nowadays widely used as a reinforcement, especially in the spar caps of wind turbine rotor blades [1]. NCFs are fabricated from UD fibre bundles by joining them together with stitch threads.…”

“…Nevertheless, fatigue properties of the laminates need to be known, since they are often subjected to uni-axial cyclic loads. Spars caps of wind turbine blades, for instance, are designed to have a service life of 20-25 years, which practically means more than 10 8 load cycles [1], [7], [8], [9], [10]. Thus, long-term durability, that is, preventing fatigue failure, is one of the most important issues within the design process of the wind turbine blades.…”

Theoretical study on the efficiency of utilization of nanoclay-CFRP composite materials in the root area of wind turbine blades

“…The spar caps region is considered as the most crucial region that carries almost 90% of the load [22]. It was formed by stacking piles of unidirectional fibres (glass or carbon) to achieve bending rigidity of the composite [18].…”

Bending properties of the multilayer‐connected biaxial weft knitted fabrics‐reinforced composites made with carbon fibers

“…The excellent mechanical properties, lower production costs, short production cycle and high property/cost ratio etc. of the MBWK fabrics‐reinforced composites make them attractive for light‐weight applications, particularly in the aviation industry, pilot helmets application, automobile industry, and wind turbine application . At present, there have been many studies focusing on formability performance of the MBWK fabrics, however, the limits are the basic researches for the mechanical properties of the MBWK fabrics‐reinforced composites, particularly the bending properties.…”