Statistical analysis of monotonic mechanical properties for unidirectional glass fiber (U)/random glass fiber (R)/epoxy hybrid and non-hybrid polymeric composites

The aim of this article is to study the variability in tensile, flexural, in-plane shear, and interlaminar shear properties of unidirectional glass fiber (U)/random glass fiber (R)/epoxy hybrid and non-hybrid composite laminates. Six kinds of laminated composites of average thickness 5.5 ± 0.2 mm and total fiber volume fraction (V_fT) = 37% were manufactured using hand lay-up technique and tested under tensile, bending, in-plane shear, and interlaminar shear loading conditions. The failure modes of all test specimens have been recorded and discussed. Two-parameter Weibull distribution function was used to statistically analyze the composite samples experimental results. Weibull graphics were plotted for each sample using experimental monotonic mechanical properties results. The Weibull distribution has also been employed to show both the failure probabilities as well as the scatter in the experimental results for the above mentioned composites. The obtained failure probability graphs for the manufactured composites under different static loading conditions are important tools for helping the designers to understand and choice the suitable material for the required design and development.