Mechanical Properties of Continuous Fiber-Reinforced Composites

1 Mechanical Properties of Continuous Fiber-Reinforced Composites 

The fiber mass fraction, and the flexural and tensile properties of the continuous fiber-reinforced composites produced by various techniques were determined according to ISO 1172, ISO 178, and EN 60, respectively. The split disk test method according to ASTM 2290 was employed to determine the circumferential strength and modulus of the pipes produced by filament winding. 

The respective average values (AV) and their standard deviations (SD) are summarized in Table 7. The experimental results are also compared with those theoretically predicted in the composite fiber direction, using the rule of mixing (ROM), from the properties already determined for the fibers and the polymer.  

The composite theoretical strengths were determined by using the mean and the standard deviation values calculated for the fiber strength at the appropriate fiber length from the Weibull distribution. The values of the fiber volume fitiction were measured experimentally. 

A major improvement over the previous results was obtained with compression molded composites, by enhancing the fiber-matrix adhesion small quantities of a carboxylic-acid-anhydride-modified polypropylene, Licomont AR 504 (supplied by Clariant, Portugal), were added in the coating chamber during the production of the towpregs. The results are summarized in Table 8. 

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