3.1. Tensile properties
The different composite specimen samples are tested in the universal
testing machine (UTM) and the samples are left to break till
the ultimate tensile strength occurs. Stress–strain curve is plotted
for the determination of ultimate tensile strength and elastic modulus.
The sample graph generated directly from the machine for
tensile test with respect to load and displacement for sisal–jute–
GFRP is presented in Fig. 4.
The load with respect to the displacement for different combination
of composite specimen is presented in Fig. 5. The results
indicated that jute–GFRP specimen gives better tensile strength
then the other two types of composites considered. The addition
of sisal fibers shows comparatively low tensile strength than the
other composites considered. The sisal–jute–GFRP hybrid composites
perform better than the sisal fibers. The comparative results of
the different composite specimen tested are presented in Fig. 6.
The ultimate tensile strength (UTS) of the sisal–GFRP composite,
jute–GFRP composite and sisal–jute–GFRP composite are in the
range of 176.20 MPa, 229.54 MPa and 200 MPa respectively. The
results indicated that the jute–GFRP composites outperformed
the other types of composites tested.
Fig. 7 shows the sample stress–strain curve obtained from the
universal testing machine when the samples are tested and Fig. 8
gives the stress–strain curve for the different composite materials
tested. The results indicate the same trend as that of the load vs
displacement curve.
From the results, it can be asserted that the jute–GFRP composites
are performing well compared to the other type of fibers used.