TY - JOUR JF - mdrsjrns JO - Modares Mechanical Engineering VL - 15 IS - 4 PY - 2015 Y1 - 2015/6/01 TI - Size-dependent pull-in instability analysis of FGM nano-beam under molecular force by differential quadrature method TT - ناپایداری کششی وابسته به اندازه نانوتیر ساخته شده از مواد تابعی مدرج تحت نیرو‌های بین‌مولکولی با روش دیفرانسیل تربیع N2 - In this paper, pull-in instability of a cantilever beam type nanoactuator made of the functionally graded material (FGM) based on higher order modified strain gradient theory investigated. It is assumed that the functionally graded beam, made of germanium and silicon, follows the volume fraction definition and law of mixtures, and its properties change as a power function through its thickness. By changing the germanium constituent volume fraction percent of the nano-beam, five different types of the nano-beams are investigated. The influences of the volume fraction index, length scale parameter and the intermolecular forces, on the pull-in instability are examined. Principle of minimum total potential energy used to derive the nonlinear governing differential equation and consistent boundary conditions which is then solved using the differential quadrature method (DQM). The present analysis is validated through direct comparisons with published other research methods and experimental results and after comparison excellent agreement has been achieved between new solution method and other experimental and numerical solution results. Besides, the results demonstrate that size effect and amount of volume fraction have a substantial impact on the pull-in instability behavior of beam-type nanoactuator. SP - 101 EP - 111 AU - Ataei, Hossein AU - Tadi Bani, Yaghoub AD - KW - Modified strain gradient Theory KW - intermolecular forces KW - Functionally graded material KW - Size effect KW - Differential Quadrature Method UR - http://mme.modares.ac.ir/article-15-1999-en.html ER -