Fatigue fibre orientation

D3479-76 Tension-tension fatigue of oriented fibre—resin matrix composites... 

The influence of the fibre orientation. Figure 3.460, fibre nature and content Figure 3.461, fibre/matrix adhesion. Figure 3.462, temperature, Figure 3.463, and especially their intercorrelated action determines the fatigue level in the composite material. 

Figure 10.13 Effect of fibre orientation on the tensile fatigue performance of glass reinforced plastics (Lilholt and Andersen).

The lifetime of advanced composite components for use in aircraft is governed primarily by allowable deformation or by fatigue. The fatigue behaviour has been the subject of many years testing by the aircraft companies, generating empirical load-cycle curves for many combinations of fibre, matrix and orientation. Humidity ingress (diffusion... 

Konopasek, L. and Hearle, J.W.S. (1977) The tensile fatigue behaviour of para-oriented aramid fibres and their fracture morphology. J. Appl. Polym. Sci., 21 2791-2815. 

The orientation of fibres is certainly an important factor influencing the fatigue strength, but experimental confirmations were published only from the tests of advanced composites with ductile matrices. Similar tests for cement-based composites are not yet available because in most applications, fibres are randomly distributed. 

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