Stability analysis of composite thin-walled pipes conveying fluid

Stability analysis of a composite thin-walled cantilever pipe conveying fluid supported at free end by linear translational and rotational springs is considered in this paper. The governing equations of the system are developed by extended Hamilton's principle for open systems. Applying extended Galerkin technique, eigenvalue analysis is implemented and the critical fluid velocity and consequently stability of the system are obtained. The critical velocity and eigenvalue are validated by comparison with the results in available literature. The numerical results are presented to investigate the effects of fiber orientation angle, volume fraction of fiber, composite layup, size of fiber, structural damping coefficient, mass fluid ratio and elastic boundary conditions on eigenvalue and critical fluid velocity of the system. It is revealed that by increasing the value of fiber orientation angle, the critical fluid velocity of the system is decreased. Furthermore, it is found that the volume fraction of fiber and size of fiber have stabilizing effects on the dynamic behavior of the system. Moreover, it is demonstrated that by increasing the value of linear spring constant at the free end, the pipe loses stability by either divergence or flutter.