Study on Effect of Fiber Orientation on Flexural Properties of Glass Fiber Reinforced Epoxy Composite Laminates for Structural Applications

Composite laminate design is an important procedure in defining the mechanical properties of laminated composite structure to be used in multi-directional service loading application. Composite technologies or manufacturers who is lack of knowledge regarding the importance of laminate design, tend to develop a composite structure that will collapse or fail below the service requirement. The purpose of this study is to determine the effect of fiber orientation on flexural properties of the designed glass fiber reinforced epoxy laminated composite. Six sets of laminates with different fiber orientation and sequence were simulated using CompositeStar© software to determine its flexural properties. Samples were fabricated to verify the simulated data and were tested in accordance to ASTM D2344. Moreover, crack pattern within the samples after the flexural test is studied. From the simulated results, it shows that laminates which have fiber in tri-direction and quasi-direction display a higher flexural modulus and strength compared to laminates with fiber in uni-directional and bi-directional. In addition, data from tested fabricated laminates samples displayed the same modulus patterns against the simulated data, with variants from 8% to 35%. Additionally, it is found that samples with fiber in ±45 direction shows a transverse and shear cracking which prolonged the cracking propagation before the samples show a complete failure.