A theoretical analysis of the influence of winding patterns on buckling load of filament wound composite pipes

While the composite pipes and cylinders manufacture by filament wound system, there are a lot of parameters that influence on the strength and mechanical behavior of them. This various mechanical behavior causes various buckling behavior. One of the most important parameters is winding pattern that have effects on critical buckling loads. So this parameter should be controlled since it effects on mechanical behavior of pipes and cylinders. In the present work the influence of winding patterns on the critical buckling load of filament wound pipes exposed by pure axial loading have been studied. The studied specimens are Glass/Epoxy tubes with [+55,-55]6 lay-up(diameter to thickness ratio d/t of 10 and length of 280mm). Parameters were all considered to be consistent to investigate the effects of winding patterns there is just difference in winding pattern between three the experimental specimens. The lay-up is the result of classical theories. Love model and Galerkin’s method were used to provide buckling equations and solve theoretically the resulted equation respectively. Although the results illustrate that there is a difference, about 2-4 percent, in terms of critical buckling load between disparate winding patterns, 16 unit cells winding pattern bears higher buckling load than other patterns. Also the results show that no evident patterns influence on buckling modes of pipes. Later, the maximum lateral buckling loads of the patterns are verified with experimental data.