نویسندگان

1 گروه مهندسی عمران، واحد شهرقدس، دانشگاه آزاد اسلامی، تهران، ایران

2 گروه مهندسی عمران، واحد رودهن، دانشگاه آزاد اسلامی، تهران، ایران

چکیده

با توجه به کاربرد فراوان لوله­‌های حاوی جریان سیال در مهندسی عمران، ارائه یک مدل ریاضی مناسب برای تحلیل پایداری آنها ضروری است. بدین منظور یک لوله بتنی تقویت شده با با نانوذرات سیلیس و حاوی جریان سیال درنظر گرفته می­‌شود. هدف این تحقیق بررسی تحلیل پایداری سازه و نشان دادن اثر نانو­ذرات و سیال درون آن است. سازه با المان پوسته استوانه­‌ای و با تئوری ردی مدل­‌سازی می‌­شود. برای به‌دست آوردن نیروی ناشی از سیال درونی از معادله ناویر- استوکس استفاده می­‌شود. برای در­نظر گرفتن اثر نانو­ذرات در لوله از مدل موری– تاناکا استفاده شده به‌طوری که اثرات انباشتگی نانو­ذرات لحاظ شده است. درنهایت با استفاده روش انرژی و اصل همیلتون، معادلات حاکم بر سازه استخراج می­‌شود. برای تحلیل پایداری سازه از روش تفاضلات مربعی استفاده می­شود و اثر پارامترهای مختلف همچون درصد حجمی نانو­ذرات، انباشتگی نانوذرات، سیال درون لوله و پارامترهای هندسی بررسی شده است. نتایج نشان می­‌دهد که وجود نانو­ذرات به‌عنوان تقویت­‌کننده لوله، منجر به تأخیر ناپایداری سازه می‌شود.

کلیدواژه‌ها

عنوان مقاله [English]

Analysis of the Effect of Fluid Velocity on the Instability of Concrete Pipes Reinforced with Nanoparticles Conveying the Fluid Flow

نویسندگان [English]

  • A. Zamani Nouri 1
  • P. Ebrahimi 2

چکیده [English]

With respect to the great application of pipes conveying fluid in civil engineering, presenting a mathematical model for their stability analysis is essential. For this purpose, a concrete pipe, reinforced by iron oxide (Fe2O3) nanoparticles, conveying fluid  is considered. The goal of this study is to investigate the structural stability to show the effects of the inside fluid and the nanoparticles. The structure was modeled by a cylindrical shell and using Reddy theory. To obtain the force induced by the inside fluid, the Navier-Stokes equation was used. To assume the effect of the nanoparticles in the pipe, the Mori-Tanaka model was utilized so that the effects of agglomeration of nanoparticles could be considered. Finally, by applying energy method and the Hamilton's principle, the governing equations were derived. For the stability analysis of the structure, differential quadrature method (DQM) was proposed and the effects of different parameters such as volume fraction of the nanoparticles and agglomeration of the nanoparticles inside fluid and geometrical parameters were investigated. The results showed that the existence of the nanoparticles as the reinforcement for the pipe led to the delay in the pipe instability.

کلیدواژه‌ها [English]

  • Concrete pipe
  • nanoparticles
  • Reddy theory
  • DQM
  • Navier-Stokes equation
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