Lateral buckling of laminated composites with delamination

Fiber reinforced laminated composite materials have superior mechanical properties, like corrosion resistance, flexibility, high impact strength, low weight/volume ratio compared, with the metallic materials. Therefore, laminated composite materials havebeen alternatively used in air, sea and land transportation vehicles instead of metallicmaterials.The main objective of this study is to investigate effect of delamination damage, which occurs in laminated composite, on lateral buckling load of composite materials. Forthis purpose, woven E-glass/epoxy laminated composite plates with eight layers wereproduced. In order to create the delamination damage teflon film having 12 µm thickness,was used. Delamination was located mid-plane of laminated composite plate.In the study, two different delamination shapes were used as rectangular andcircular. To investigate the effect of delamination, which have different shape and size, on lateral buckling load of laminated composites; test specimens were classified in two different categories which consist of different twenty two series. In the first of these categories (eight different series), the rectangular and circular delamination areas wereselected as fixed and 600 mm^2 . In this category, the aspect ratio of square delamination and also minor and major axis ratio of circular delamination were taken as a/b=1, 2, 3 and 4. Asfor that in the second category (fourteen different series), the ratios of square and circularvidelamination were selected as a/b=0.5, 0.6, 0.75, 1, 1.3, 1.6, and 2. To better understanding effect of delamination on the lateral buckling behavior, the experimental and numericalresults of specimens with and without delamination were compared with each other?s.Ansys 12.1 software was used to investigate the lateral buckling behavior of laminated composites with delamination. Obtained numerical results have good agreement with experimental results.In addition, Weibull distributions, which have 95% reliability, were obtained withusing critical buckling load values. ReliaSoft Weibull 8++ program was used for statistical study.