This research studied the buckling of composite columns made from glass fiber reinforced unsaturated polyester. The composite specimens were prepared by hand lay-up technique with different fiber volume fraction Vf, aspect ratio and angle of fibers when reinforced with coarse and fine woven fibers. Mathematical models were done by using statistical analysis which show the critical load of the composite column as a function of volume fraction, fiber angle and aspect ratio.
The results show that the maximum value of the critical load can be observed at volume fraction Vf =11%, aspect ratio L/T = (3.5) and fiber angle θ = (0º/90º) for fine fiber was (500.72 N). Also its found the maximum critical load for coarse fiber can be observed at Vf =8%, L/T= (3.5) and θ = (0º/90º) was (400.4 N).