This work deals with the effect of volume fractions (0, 10, and 20%) on fatigue behavior of unsaturated polyester
matrix reinforced with E-glass chopped fiber experimentally and numerically. The composite materials are
manufactured by hand layup technique, which is formulated by E-glass fibers immersed in polyester resin. The
experimental part includes achieving mechanical tests to estimate the mechanical properties, which represent by
tensile, and fatigue tests under completely reversed cyclic loading. The results shows that the tensile strength and
elastic modulus of such composite is increased by 44.4% and 60.8% respectively when the volume fraction
increased from 0% to 20%, while the fatigue strength of composite reinforced with 20% of volume fraction
increased by about 48% compared with that pure polyester. The numerical part includes a finite element method
by using ANSYS/16 workbench software to verify experimental data and good agreement has found with
maximum overall average error 7%.