فهرست مقالات Dynamic buckling

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  1 - Electro-Thermo-Dynamic Buckling of Embedded DWBNNT Conveying Viscous Fluid
  A Ghorbanpour Arani M Hashemian
  In this paper, the nonlinear dynamic buckling of double-walled boron-nitride nanotube (DWBNNT) conveying viscous fluid is investigated based on Eringen's theory. BNNT is modeled as an Euler-Bernoulli beam and is subjected to combine mechanical, electrical and thermal lo چکیده کامل

  In this paper, the nonlinear dynamic buckling of double-walled boron-nitride nanotube (DWBNNT) conveying viscous fluid is investigated based on Eringen's theory. BNNT is modeled as an Euler-Bernoulli beam and is subjected to combine mechanical, electrical and thermal loading. The effect of viscosity on fluid-BNNT interaction is considered based on Navier-Stokes relation. The van der Waals (vdW) interaction between the inner and outer nanotubes is taken into account and the surrounding elastic medium is simulated as Winkler and Pasternak foundation. Considering the charge equation for coupling of mechanical and electrical fields, Hamilton's principle is utilized to derive the motion equations based on the von Kármán theory. Dynamic buckling load is evaluated using differential quadrature method (DQM). Results show that dynamic buckling load depends on small scale factor, viscosity, elastic medium parameters and temperature changes. Also, dynamic instability region is discussed for various conditions. پرونده مقاله
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  2 - Dynamic Stability of Laminated Composite Plates with an External Smart Damper
  M Hoseinzadeh J Rezaeepazhand
  The dynamic stability of a composite plate with external electrorheological (ER) damper subjected to an axial periodic load is investigated. Electrorheological fluids are a class of smart materials, which exhibit reversible changes in mechanical properties when subjecte چکیده کامل

  The dynamic stability of a composite plate with external electrorheological (ER) damper subjected to an axial periodic load is investigated. Electrorheological fluids are a class of smart materials, which exhibit reversible changes in mechanical properties when subjected to an electric field. As a result, the dynamic behavior of the structure is changed. The ER damper is used for suppressing the vibrations and improving the stability of the system. The Bingham plastic model is employed to express the behavior of the ER fluid. The finite element model of the structure is developed and constant acceleration average method is used to obtain the response of the system. Effect of different parameters such as the electric field, the orientation of the ER damper, the initial gap between the two electrodes of the ER damper and the stacking sequences of the plate on the first instability boundaries of the composite plate are investigated. پرونده مقاله
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  3 - Nonlinear Dynamic Buckling of Viscous-Fluid-Conveying PNC Cylindrical Shells with Core Resting on Visco-Pasternak Medium
  A Ghorbanpour Arani A.A Mosallaie Barzoki R Kolahchi
  The use of intelligent nanocomposites in sensing and actuation applications has become quite common over the past decade. In this article, electro-thermo-mechanical nonlinear dynamic buckling of an orthotropic piezoelectric nanocomposite (PNC) cylindrical shell conveyin چکیده کامل

  The use of intelligent nanocomposites in sensing and actuation applications has become quite common over the past decade. In this article, electro-thermo-mechanical nonlinear dynamic buckling of an orthotropic piezoelectric nanocomposite (PNC) cylindrical shell conveying viscous fluid is investigated. The composite cylindrical shell is made from Polyvinylidene Fluoride (PVDF) and reinforced by zigzag boron nitride nanotubes (BNNTs) where characteristics of the equivalent PNC being determined using micro-mechanical model. The poly ethylene (PE) foam-core is modeled based on Pasternak foundation. Employing the charge equation, Donnell's theory and Hamilton's principle, the four coupled nonlinear differential equations containing displacement and electric potential terms are derived. Harmonic differential quadrature method (HDQM) is applied to obtain the critical dynamic buckling load. A detailed parametric study is conducted to elucidate the influences of the geometrical aspect ratio, in-fill ratio of core, viscoelastic medium coefficients, material types of the shell and temperature gradient on the dynamic buckling load of the PNC cylindrical shell. Results indicate that the dimensionless critical dynamic buckling load increases when piezoelectric effect is considered. پرونده مقاله