Aerospace Science and Technology
Bahram Ghorbani Rezaei; Jafar Eskandari Jam
Abstract
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 ...
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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.
M. Noorabadi; N. Namdaran; M. Rahnama; Jafar Eskandari Jam
Volume 11, Issue 2 , October 2017, , Pages 13-22
Abstract
The aim of this study is to investigatethe effective parameters on vibrations of circular cylindrical shells with fixed rotary speed andresting elastic foundation by means of analytical and finite element numerical simulation. First, the governing equations are derived using the theory of Donnell, considering ...
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The aim of this study is to investigatethe effective parameters on vibrations of circular cylindrical shells with fixed rotary speed andresting elastic foundation by means of analytical and finite element numerical simulation. First, the governing equations are derived using the theory of Donnell, considering the centrifugal forces,Coriolis acceleration, and the initial annular tension. Then, the analytical solution for cylindrical shells isintroduced under simply supported conditions. Further, the effect of parameters such as therotational speed of the shell, its lay-up, fiber angle, and the stiffness of the elastic foundation on the values of natural frequency and the critical velocity of the shells are studied. The analytical solution results are in good compatibility with the results achieved from the finite element method.