A force-feedback control system for VIV experiments is designed and evaluated for the purpose of achieving high accuracy free vibration tests. Through an organized approach, this work details specific methods for minimizing the combined effect of mass and damping using control system fundamentals. The dynamics of the closed-loop system are analyzed, a numerical model constructed and a control s...

This paper aims at presenting a new efficient element for free vibration and instability analysis of Axially Functionally Graded Materials (FGMs) non-prismatic beams using Finite Element Method (FEM). Using concept of Basic Displacement Functions (BDFs), two- node element extends  to three-node element for obtaining much more exact results using FEM. First, BDFs are introduced and computed usin...

purpose– analysis of non-prismatic beams has been focused of attention due to wide use in complex structures such as aircraft, turbine blades and space vehicles. apart from aesthetic aspect, optimization of strength and weight is achieved in use of this type of structures. the purpose of this paper is to present new shape functions, namely 3-node basic displacement functions (bdfs) for derivati...

in this paper, natural frequencies of the sandwich plates with soft flexible core and composite face sheets are obtained. three-dimensional (3d) finite element method (fem) is used for constructing and analyzing of the sandwich plates to obtain their natural frequencies. continuity conditions for transverse shear stresses at the interfaces as well as transverse flexibility and transverse normal...

In this study, a semi analytical method for transverse and axial vibration of single-walled boron nitride nanotube (SWBNNT) under moving a nanoparticle is presented. The surrounding elastic medium as Pasternak foundation and surface stress effect are included in the formulations of the proposed model. Using Timoshenko beam theory (TBT), Hamilton’s principle and nonlocal piezoelasticity theory, ...

In this note, small amplitude free vibration of a double-beam system in presence of inner layer nonlinearity is investigated. The nonlinearity is due to inner layer material and is not related to large amplitude vibration. At first, frequencies of a double-beam system with linear inner layer are studied and categorized as synchronous and asynchronous frequencies. It is revealed that the inner l...