This study presents the effect of vertical and horizontal oriented cracks on free vibration response for circular annular thin plates. To investigate dynamic behavior damaged structures are modeled separately considering horizontal/vertical orientations, ten different locations, four crack sizes. For plates, placed in middle between outer inner edges to directions. The first five resonant frequ...

In the present paper, the free vibration characteristics of nanobeams embedded in an elastic medium are investigated. Inclusion of size effects is considered in the analysis by incorporating Eringen’s nonlocal elasticity continuum into the classical Euler–Bernoulli beam theory. To include the surrounding elastic medium, the Pasternak elastic foundation model is utilized, including shear deforma...

This paper presents the most important multilevel inverter topologies like diode-clamped inverter (neutral-point clamped), capacitor-clamped (flying capacitor), and cascaded multicell( H-Bridge ) with separate dc sources. A Comparison of 5-level hybrid cascaded inverter with PWM method, 5 level diode clamped inverter & 5 level capacitor coupled inverter is also presented in this paper. This pap...

The aim of this contribution is to present numerical comparisons model-order reduction methods for geometrically nonlinear structures in the general framework finite element (FE) procedures. Three different are compared: implicit condensation and expansion (ICE), quadratic manifold computed from modal derivatives (MD), direct normal form (DNF) procedure, latter expressing reduced dynamics an in...

In the previous literature, the introduction of the virtual-space-vector (VV) concept for the three-level, three-leg neutral-point-clamped converter has led to the definition of pulsewidth modulation (PWM) strategies, guaranteeing a dc-link capacitor voltage balance in every switching cycle under any type of load, with the only requirement being that the addition of the three phase currents equ...

For medium voltage, high power applications 3-phase neutral point clamped AC-DC multilevel converters are becoming a good choice. In this paper the performance of a 3-phase neutral point clamped Active Front End three level converter for high power application with simplified control scheme is presented. A complete mathematical model of the control scheme is developed and performance is investi...

in this paper, eringen’s nonlocal elasticity and timoshenko beam theories are implemented to analyze the bending vibration for non-uniform nano-beams.  the governing equations and the boundary conditions are derived using hamilton’s principle. a generalized differential quadrature method (gdqm) is utilized for solving the governing equations of non-uniform timoshenko nano-beam for pinned-pinned...

Direct torque control (DTC) is a control technique in AC drive systems to obtain high performance torque control. The classical DTC drive contains a pair of hysteresis comparators and suffers from variable switching frequency and high torque ripple. These problems can be solved by using space vector depending on the reference torque and flux. In this paper the space vector modulation technique ...