Understanding the compressive strength mechanisms of CFRP to design masts and hydrofoils for racing yachts
Topic(s) : Special Sessions
Co-authors :
Pierre-Yves MECHIN (FRANCE), Vincent KERYVIN (FRANCE)Abstract :
The masts and foils of racing yachts are generally made from continuous carbon fibre composite (CFRP) structures. The design of racing yachts does not need to follow strict standard rules and new materials can be developed rapidly. The loads are not well known, but these appendages clearly undergo pure compression and/or bending. The constraint of rapid design requires rapid dimensioning tools to estimate compressive strength. The Budiansky and Fleck model [1], based on micro-buckling of the fibres, makes this possible and also allows us to understand the effect of certain contributions: the initial fibre waviness due to the manufacturing processes and the non-linear shear behaviour of the ply.
For masts and hydrofoils, we are looking for a combination of stiffness and strength. The addition of nanofillers to the matrix is a classic way of improving stiffness [2]. In this work, we propose to understand why epoxy resins with silica nanofillers significantly improve the compressive strength of CFRPs with intermediate modulus carbon fibres, whereas they fail to do so with high modulus carbon fibres.
The first focus will be on the influence of non-linear shear behaviour. Computational homogenisation is used to study the influence of fibre arrangement and nanofiller content in the resin [3]. Regular and random microstructures are generated even with very high fibre volume fractions. The initial fibre waviness will then be measured by automated image analysis using artificial intelligence based on the methodology proposed by Yurgartis [4].
It will be shown that there is an interplay between the fibre plastic instability and the shear strength of the ply, which may or may not lead to the complete development of the resin and the fibre potential for enhancing compressive strength.
For masts and hydrofoils, we are looking for a combination of stiffness and strength. The addition of nanofillers to the matrix is a classic way of improving stiffness [2]. In this work, we propose to understand why epoxy resins with silica nanofillers significantly improve the compressive strength of CFRPs with intermediate modulus carbon fibres, whereas they fail to do so with high modulus carbon fibres.
The first focus will be on the influence of non-linear shear behaviour. Computational homogenisation is used to study the influence of fibre arrangement and nanofiller content in the resin [3]. Regular and random microstructures are generated even with very high fibre volume fractions. The initial fibre waviness will then be measured by automated image analysis using artificial intelligence based on the methodology proposed by Yurgartis [4].
It will be shown that there is an interplay between the fibre plastic instability and the shear strength of the ply, which may or may not lead to the complete development of the resin and the fibre potential for enhancing compressive strength.