Failure analysis of pinned joint laminated composite materials

The aim of study was to investigate the effects of different environmental conditions on the failure mode, maximum failure load and mechanical properties of two parallel pinned joint of glass fiber reinforced woven epoxy composite plates. Therefore, the study carried out in three stages. In the first stage, dry composite plates were exposed to tensile test. In the second stage, composite plates kept in sea water for 3 months and third stage composite plates kept in sea water for 6 months were exposed to tensile test. The obtained test results were compared with the dry composite plates.For the different geometrical parameters of composite plates were investigated both experimentally and numerically. The edge distance-to-upper hole diameter (E/D), the two hole-to-hole centre diameter (K/D), the distance from the upper or the lower edge of the specimen to the centre of the hole-to-hole diameter (M/D), and the width of the specimen-to-hole diameter (W/D) ratios were selected as parameters. This study, E/D, K/D, M/D, W/D were determined from 2 to 5, 2 to 4, 1 to 4, and 4 to 12, respectively.The numerical study was performed by using prograssive failure analysis method with ANSYS 11.0 finite element program. Tsai-Wu failure criterion was used in the prograssive failure analysis method and were obtained failure modes, failure loads.The effect of sea water decreased of failure load values, and mechanical properties values of two parallel pinned joint of glass fiber reinforced woven epoxy composite plates. Therefore, it was resulted that the sea water reduced the strenght of composite plate. Experimental and numerical results of the study were found to be compatible with each other.Key Words: Pinned Joint, Prepreg, Failure Analysis, Sea Water, Finite Element Method, Environmental Conditions, Mechanical Analysis, Laminated Composite.