UV radiation effect on static and dynamic behavior of fiber reinforced Composite plates


The exposure to sever environment has undesired impact on the behavior of mechanical and physical properties of composite materials. This research studies the effect of ultraviolet radiation on composite material of symmetrical and anti-symmetrical cross ply [0/90] 8-layer glass-fiber reinforced composite laminates. The samples were placed inside a special designed container and exposed to the radiation which simulates the natural sun light for 2000 hrs .The flexural properties (strength and stiffness) were determined experimentally before and after exposure to the radiation. Samples were examined using the three point bending test method to determine the properties of the composite laminate. Analytical solution based on the classical laminates theory been used, where shear effect taken into consideration because of and due to merging this theory with three point bending equations to compare the convergence between experimental and theoretical results of samples without environmental effect. The finite element analysis method were used to verify the experimental results ,and analyze the vibration characteristics to obtain the natural frequencies , response and stress distribution when exposed to radiation for different time range and harmonic load .It was shown that the exposure to ultraviolet radiation reduces the bending strength, were the symmetrical laminates lose 64% of its bending strength after 2000 hrs of exposure ,while the anti-symmetrical laminates lose 34% for the same time. Also it was shown that the natural frequencies of the cantilever and simply supported plates which is similar to the three point bending specimen reduces with the increased exposure time .The result of displacement and effective stresses at point of the applied load for symmetrical cantilever plates were directly proportional with increase of load and exposure time of radiation , while for the anti-symmetrical plates reduces with the increase of load and exposure time