بررسی رفتار ارتعاشی پوسته های کامپوزیتی مخروطی تقویت شده با شبکه ناهمسان مشبک با روش تفاضل مربعات

نوع مقاله : مقاله پژوهشی

نویسنده

عضو هیات علمی / دانشکده مهندسی، دانشگاه امام علی (ع)، تهران، ایران

چکیده

پژوهش حاضر با هدف مطالعه رفتار ارتعاشی پوسته های کامپوزیتی مخروطی تقویت شده با شبکه ناهمسان مشبک، با استفاده از روش تحلیلی انجام گردیده است. بدین منظور، از روش معادلسازی جهت تعیین پارامترهای سفتی معادل سخت کننده ها استفاده می گردد. در این روش، مجموعه سخت کننده ها با یک پوسته معادل که از نظر سفتی معادل یکدیگر می باشند، جایگزین می گردد و سپس جهت دستیابی به سفتی معادل کل سازه، با سفتی های پوسته جمع می گردند. سخت کننده ها به صورت تیر مدلسازی می گردند تا توانایی تحمل بار برشی و لنگرهای خمشی همراه با بارهای محوری را دارا باشند. معادلات دیفرانسیل حاکم بر مسئله با اعمال اصل همیلتون و بر مبنای تئوری مرتبه اول تغییر شکل برشی استخراج و سپس با استفاده از روش تفاضل مربعات به گروهی از معادلات جبری تبدیل می گردند. در ادامه رابطه مسئله مقدار ویژه استخراج و در نتیجه آن فرکانس طبیعی محاسبه می گردند. جهت صحت سنجی نتایج، مقایسه ای میان نتایج بدست آمده و نتایج سایر محققین صورت گرفته است. سپس تاثیر پارامترهای مختلف نظیر زاویه نیم رأس مخروط، عدد موج محیطی و اثر شرایط مرزی مختلف بر فرکانس های طبیعی سیستم مورد ارزیابی قرار گرفته است.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Vibrational behavior investigation of composite conical shells reinforced by an anisogrid lattice structure using differential quadrature method

نویسنده [English]

  • Ali Asghar Naderi
Assistant Professor.Department of Engineering, Imam Ali University, Tehran, Iran
چکیده [English]

The present study aims to investigate the vibrational behavior of composite conical shells reinforced by an anisogrid lattice structure, using the analytical method. For this purpose, the smeared method was employed to determine the equivalent stiffness contribution of the stiffeners. In this approach, the smeared method was used to superimpose the stiffness contribution of the stiffeners with those of the shell to obtain the equivalent stiffness of the whole structure. The stiffeners were modeled as beams that can support shear forces and bending moments along with the axial forces. The governing partial differential equations of the problem are derived by applying Hamilton's principle and based on the first-order shear deformation theory, and then they are converted into a group of algebraic equations by using the differential quadrature method. Then, eigenvalue problem, and as a result, natural frequencies are calculated. In order to validate the results, comparisons of the present results with those of other studies are performed. Then. the effect of different parameters such as semi-vertex angle, circumferential wave number and the effect of different boundary conditions on the natural frequencies of the system has been evaluated.

کلیدواژه‌ها [English]

  • "vibrational behavior"
  • "composite conical shells"
  • "anisogrid lattice structure"
  • "smeared method"
  • "differential quadrature method"
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