Large Amplitude Dynamic Instability of a Graphene-Reinforced Pipe Conveying Pulsating Flow

In many industries' applications, one deals with pipes conveying fluid. Besides, the implementation of advanced materials in manufacturing of new-brand structures is developing. Consequently, in this paper, one of the most important dynamics analyzes that an advanced pipe conveying fluid may meet it is addressed. For the first time, linear and nonlinear dynamics of a pipe reinforced with graphene nanoplatelets (GPL pipe) that conveys pulsating flow is presented. The Euler-Bernoulli beam model follows the plug flow model in order to formulate the problem. The method of multiple scales (MMS) applied to the discretized couple nonlinear gyroscopic governing equations with the aim of specifying the instability region and the steady-state response of the GPL pipe subjected to the principal parametric resonance of one of its modes, as a consequence of pulsating flow. Respectively, the Floquet theory and the Runge-Kutta fourth-order (RK4) method are applied to the linear governing equations and nonlinear governing equations for the sake of confirming the current MMS results. It is deduced that a small amount usage of GPL reinforcement phase improves substantially the resistance against static instability, and the critical fluid excitation amplitude fraction, meanwhile declines the instability region bandwidth, and the steady-state response of the pipe. In contrary, it is confirmed that a heavier fluid makes reverse the preceding statements with respect to a lighter fluid. The aforementioned findings shed light on the essential design keys that outstandingly affect the mechanics of the GPL pipe conveying pulsating fluid that lead and conduct forthcoming studies and open new horizons for designers in industry implementations.