Nonlinear dynamics of PFG cylindrical shells reinforced with oblique stiffeners under viscous fluid flow

IF 6.6 1区工程技术 Q1 ENGINEERING, CIVIL

Thin-Walled Structures Pub Date : 2025-09-05 DOI:10.1016/j.tws.2025.113925

Kamran Foroutan , Farshid Torabi

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引用次数: 0

Abstract

In this paper, the nonlinear dynamic (ND) behavior of porous functionally graded (PFG) cylindrical shells (CSs) reinforced with oblique stiffeners under viscous, compressible, and non‑isentropic internal fluid flow is comprehensively analyzed using a semi‑analytical approach. Moreover, this study investigates two variations of PFG: one featuring an even porosity distribution (EPD) and the other exhibiting an uneven porosity distribution (UEPD). Lekhnitskii’s smeared stiffener approach is utilized to model the stiffeners. The nonlinear governing equations (NGEs) are formulated based on Donnel shell theory (DST) incorporating von Kármán geometric nonlinearity. Then, these equations are discretized via Galerkin’s method, and a three-term approximate solution for the deflection is established. An approach utilizing the P-T method is developed for analyzing the ND behavior of PFG-CSs reinforced with oblique stiffeners in the presence of fluid flow, providing a continuous semi-analytical solution across the full-time domain with highly accurate numerical results. This method combines a piecewise-constant argument with Taylor series expansions, hence its designation as the P-T method. The study advances the state of the art by integrating oblique stiffener effects, porosity variations, and realistic fluid–structure interaction in the analysis of PFG-CSs, thereby capturing the influence of both material distribution and internal fluid properties on their ND responses. The results demonstrate that stiffener angles, porosity distribution, and fluid characteristics significantly affect the ND behavior, providing valuable insights and design guidelines for marine risers, heavy‑oil pipelines, and aerospace propellant tanks where fluid–structure interactions are critical to structural safety and performance.

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粘性流体作用下斜加劲PFG圆柱壳的非线性动力学

本文采用半解析方法，全面分析了斜肋加筋多孔功能梯度圆柱壳在粘性、可压缩和非等熵内部流体流动下的非线性动力学行为。此外，本研究还研究了PFG的两种变化：一种具有均匀孔隙度分布（EPD），另一种具有不均匀孔隙度分布（UEPD）。采用Lekhnitskii的涂抹加劲板方法对加劲板进行建模。基于Donnel壳理论，结合von Kármán几何非线性，建立了非线性控制方程。然后，利用伽辽金方法对这些方程进行离散化，建立了挠度的三项近似解。采用P-T法分析了斜加强PFG-CSs在流体存在下的ND行为，提供了一个跨全时域的连续半解析解，并具有高精度的数值结果。这种方法结合了分段常数参数和泰勒级数展开，因此被称为P-T方法。该研究通过在PFG-CSs分析中整合斜加劲效应、孔隙度变化和现实的流固耦合，从而捕捉材料分布和内部流体性质对其ND响应的影响，从而推进了目前的研究水平。结果表明，加强角、孔隙度分布和流体特性显著影响ND行为，为海洋立管、重油管道和航空航天推进剂储罐提供了有价值的见解和设计指南，在这些领域，流固耦合对结构安全和性能至关重要。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Thin-Walled Structures 工程技术-工程：土木

CiteScore

9.60

自引率

20.30%

发文量

801

审稿时长

66 days

期刊介绍： Thin-walled structures comprises an important and growing proportion of engineering construction with areas of application becoming increasingly diverse, ranging from aircraft, bridges, ships and oil rigs to storage vessels, industrial buildings and warehouses. Many factors, including cost and weight economy, new materials and processes and the growth of powerful methods of analysis have contributed to this growth, and led to the need for a journal which concentrates specifically on structures in which problems arise due to the thinness of the walls. This field includes cold– formed sections, plate and shell structures, reinforced plastics structures and aluminium structures, and is of importance in many branches of engineering. The primary criterion for consideration of papers in Thin–Walled Structures is that they must be concerned with thin–walled structures or the basic problems inherent in thin–walled structures. Provided this criterion is satisfied no restriction is placed on the type of construction, material or field of application. Papers on theory, experiment, design, etc., are published and it is expected that many papers will contain aspects of all three.