مجید قدیری

[ 1 ] - تحلیل ارتعاشات نانوپوسته مدرج تابعی احاطه شده توسط بستر الاستیک با استفاده از نظریۀ تنش کوپل اصلاح شده

هدف از این پژوهش بررسی رفتار ارتعاشی یک نانو پوسته استوانه ای مدرج تابعی بر اساس تئوری تنش کوپل اصلاح شده می باشد. همچنین در اطراف این نانوپوسته بستر الاستیک پاسترناک در نظر گرفته شده است که در این مدل علاوه بر ثابت فنری نوع وینکلر، ثابت برشی نیز لحاظ شده است. علاوه بر این شرایط مرزی نانوپوسته در دو انتها به صورت تکیه گاه ساده فرض شده است. نانو پوسته استوانه ای درجه بندی شده تابعی، از ترکیب آلو...

[ 2 ] - بررسی ارتعاشات غیرخطی سیستم کابل حامل جرم و فنر و دمپر تحت اثر حرکت شتاب‌دار جرم متصل به آن

در این نوشتار ارتعاشات غیر خطی کابل حامل جرم متحرک که به‌کمک فنر و دمپر به کابل متصل شده، مورد بررسی قرار گرفته است. یک انتهای کابل ثابت، و انتهای دیگر آن، با اختلاف ارتفاع، غیرثابت است. کرنش مماسی کابل صفر فرض شده، اما طول کابل دائماً در حال تغییر است و این تغییر طول کابل، به آن اجازه‌ی ارتعاش می‌دهد. این تغییرات به‌گونه‌یی است که اختلاف کشش در انتهای غیر ثابت کابل صفر شود. ارتعاشات کابل به‌صور...

[ 3 ] - In-Plane and out of Plane Free Vibration of U-Shaped AFM Probes Based on the Nonlocal Elasticity

Atomic force microscope (AFM) has been developed at first for topography imaging; in addition, it is used for characterization of mechanical properties. Most researches have been primarily focused on rectangular single-beam probes to make vibration models simple. Recently, the U-shaped AFM probe is employed to determine sample elastic properties and has been developed to heat samples locally. I...

[ 4 ] - A Nonlocal First Order Shear Deformation Theory for Vibration Analysis of Size Dependent Functionally Graded Nano beam with Attached Tip Mass: an Exact Solution

In this article, transverse vibration of a cantilever nano- beam with functionally graded materials and carrying a concentrated mass at the free end is studied. Material properties of FG beam are supposed to vary through thickness direction of the constituents according to power-law distribution (P-FGM). The small scale effect is taken into consideration based on nonlocal elasticity theory of E...

[ 5 ] - Vibration Analysis of a Rotating Nanoplate Using Nonlocal Elasticity Theory

The nanostructures under rotation have high promising future to be used in nano-machines, nano-motors and nano-turbines. They are also one of the topics of interests and it is new in designing of rotating nano-systems. In this paper, the scale-dependent vibration analysis of a nanoplate with consideration of the axial force due to the rotation has been investigated. The governing equation and b...

[ 6 ] - Fracture Mechanics Analysis of Fourth Lumbar Vertebra in Method of Finite Element Analysis

Objective: In this paper, finite element model of the L4 vertebra subjected to combination of compression and flexion loading in isotropic and anisotropic cases is investigated. Methods: In both cases, the vertebra is considered homogeneous. Also, the body of vertebra is divided to cancellous and cortical sections in anisotropic model, but the process is assumed isotropic such as isotropic mode...

[ 7 ] - Fracture Mechanics Analysis of Fourth Lumbar Vertebra in Method of Finite Element Analysis

Objective: In this paper, finite element model of the L4 vertebra subjected to combination of compression and flexion loading in isotropic and anisotropic cases is investigated. Methods: In both cases, the vertebra is considered homogeneous. Also, the body of vertebra is divided to cancellous and cortical sections in anisotropic model, but the process is assumed isotropic such as isotropic mode...

[ 8 ] - Influence of Temperature Change on Modal Analysis of Rotary Functionally Graded Nano-beam in Thermal Environment

The free vibration analysis of rotating functionally graded (FG) nano-beams under an in-plane thermal loading is provided for the first time in this paper. The formulation used is based on Euler-Bernoulli beam theory through Hamilton’s principle and the small scale effect has been formulated using the Eringen elasticity theory. Then, they are solved by a generalized differential quadrature meth...

[ 9 ] - Influence of Rotation on Vibration Behavior of a Functionally Graded Moderately Thick Cylindrical Nanoshell Considering Initial Hoop Tension

In this research, the effect of rotation on the free vibration is investigated for the size-dependent cylindrical functionally graded (FG) nanoshell by means of the modified couple stress theory (MCST). MCST is applied to make the design and the analysis of nano actuators and nano sensors more reliable. Here the equations of motion and boundary conditions are derived using minimum potential ene...

[ 10 ] - Vibration Analysis of Rotary Tapered Axially Functionally Graded Timoshenko Nanobeam in Thermal Environment

In this paper, vibration analysis of rotary tapered axially functionally graded (AFG) Timoshenko nanobeam is investigated in a thermal environment based on nonlocal theory. The governing equations of motion and the related boundary conditions are derived by means of Hamilton’s principle based on the first order shear deformation theory of beams. The solution method is considered using generaliz...

[ 11 ] - Vibration Analysis of Size-Dependent Piezoelectric Nanobeam Under Magneto-Electrical Field

The damping vibration characteristics of magneto-electro-viscoelastic (MEV) nanobeam resting on viscoelastic foundation based on nonlocal strain gradient elasticity theory (NSGT) is studied in this article. For this purpose, by considering the effects of Winkler-Pasternak, the viscoelastic medium consists of linear and viscous layers. with respect to the displacement field in accordance with th...