Strain-Rate Sensitivity of Fiber-Reinforced Polymer Matrix

Abstract

This paper evaluates the strain-rate sensitivity of fiber-reinforced polymer matrix. The methodology involved extracting fiber from plantain pseudostem, prepared and treated with nine different liquids; acetone, acetylation, glycerol, methanol, mercerization (NaOH), Methyl ethyl ketone peroxide (MEKP), hydrogen peroxide, potassium permanganate, and phosphoric acid. The fiber was prepared with the objective of molding cylindrical shape for mechanical test samples with continuous and unidirectional aligned fibers. Contact angle measurement was carried out in all the treated and untreated samples using two different probe liquid; water and glycerol. Matlab software tools were used in the mathematical analysis of the data generated from the experiments. Strain rate was calculated from adhesive energy- tensile stress model and used to determine the strain-rate sensitivity index, m for treated plantain fiber-reinforced polyester matrix. The low values of the strain rate suggest that the fiber sliding against the polymer matrix to which it was bonded was infinitesimally low and would not cause noticeable changes in their bonding between fiber and matrix. Since the strain rate sensitivity index in this study is less than 0.30, it can be concluded that the reinforced plastic is relaxed and so would not be adversely subjected to stress build up at the interface between the fiber and the matrix. This work shows that the use of adhesive energy-stress concept to determine the strain rate is valid since the values of strain rate indices calculated are comparable with values reported in the literature.