Mohammad Hashemian

Islamic Azad University, Khomeinishahr Branch

[ 1 ] - Free Vibration Analysis of Sandwich Micro Beam with Piezoelectric Based on Modified Couple Stress Theory and Surface Effects

In this paper, the free vibration analysis of sandwich micro beam with piezoelectric layers based on the modified couple stress and surface elasticity theories are investigated. The Hamilton’s principle is employed to derive the sandwich micro beam with piezoelectric based on modified couple stress theory incorporating with Gurtin- Murdoch surface theory. The generalized differential quadrature...

[ 2 ] - Vibration and Buckling of Double-Graphene Sheet-Systems with an Attached Nanoparticle Based on Classical and Mindlin Plate Theories Considering Surface Effects

Vibration of double-graphene sheet-system is considered in this study. Graphene sheets are coupled by Pasternak elastic medium. Classic and Mindlin plate theories are utilized for modeling the coupled system. Upper sheet carries a moving mass. Governing equations are derived using energy method and Hamilton’s principle considering surface stress effects and nonlocal parameter.  Using Galerkin m...

[ 3 ] - Dynamic Stability of Single Walled Carbon Nanotube Based on Nonlocal Strain Gradient Theory

This paper deals with dynamic Stability of single walled carbon nanotube. Strain gradient theory and Euler-Bernouli beam theory are implemented to investigate the dynamic stability of SWCNT embedded in an elastic medium. The equations of motion were derived by Hamilton principle and non-local elasticity approach. The nonlocal parameter accounts for the small-size effects when dealing with nano-...

[ 4 ] - Dynamic Stability of Nano FGM Beam Using Timoshenko Theory

Based on the nonlocal Timoshenko beam theory, the dynamic stability of functionally gradded (FG) nanoeams under axial load is studied in thermal environment, with considering surface effect. It is used power law distribution for FGM and the surface stress effects are considered based on Gurtin-Murdoch continuum theory. Using Von Karman geometric nonlinearity, governing equations are derived bas...

[ 5 ] - Study of The Effect of Hole Location on Stress Analysis of a Plate Subjected to Uni-axial Load by Using Numerical and Exact Solution

In the present study, stress analysis and explicit solution of rectangular plate with arbitrarily located circular hole, subjected to linear normal stresses on two opposite edges, has been investigated. Airy function and hoop stresses occurring at the edge of the circular have been computed. In this method 2D dimension elasticity and Airy stress function was used. The present method for explici...

[ 6 ] - تحلیل ارتعاشات و کنترل میکروتیر یکسر گیردار به همراه لایه های عملگر و حسگر پیزوالکتریک با فرض اثرات سطح

امروزه پیش‌بینی رفتار ارتعاشی و دینامیکی سازه‌های میکرو مورد توجه بسیاری از پژوهشگران قرار گرفته است. در این پژوهش تحلیل ارتعاشات و کنترل میکروتیر یکسر گیردار به همراه لایه‌های پیزوالکتریک عملگر و حسگر با فرض اثرات تنش سطح مورد ارزیابی قرار گرفته است. معادلات دیفرانسیل حاکم با استفاده از روش انرژی و اصل همیلتون استخراج شده و از روش مجموع مربعات دیفرانسیلی تعمیم یافته برای گسسته-سازی و تبدیل معا...