• فهرس المقالات Follower force

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        1 - Static and Dynamic Stability Analysis of Thick CNT Reinforced Beams Resting on Pasternak Foundation Under Axial and Follower Forces
        M Hosseini A Ghorbanpour Arani M karamizadeh Sh Niknejad A Hosseinpour
        In this paper, a numerical solution is presented for static and dynamic stability analysis of carbon nanotube (CNT) reinforced beams resting on Pasternak foundation. The beam is considered to be exposed to compressive axial and follower forces at its free end. The beam أکثر
        In this paper, a numerical solution is presented for static and dynamic stability analysis of carbon nanotube (CNT) reinforced beams resting on Pasternak foundation. The beam is considered to be exposed to compressive axial and follower forces at its free end. The beam is modeled based on the Reddy’s third order shear deformation theory and governing equations and external boundary conditions are derived using Hamilton’s principle. The set of governing equations and boundary conditions are solved numerically using differential quadrature method. Convergence and accuracy of results are confirmed and effect of various parameters on the stability region of the beam is investigated including volume fraction and distribution of CNTs, width and thickness of the beam and elastic and shear coefficients of the foundation. تفاصيل المقالة
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        2 - Effect of Follower Force on Vibration Frequency of Magneto-Strictive-Faced Sandwich Plate with CNTR Composite Core
        M.R Ghorbanpour Arani Z Khoddami Maraghi
        This study deals with the vibration response of sandwich plate with nano-composite core and smart magneto-strictive face sheets. Composite core is reinforced by carbon nanotubes (CNTs) and its effective elastic properties are obtained by the rule of Mixture. Terfenol-D أکثر
        This study deals with the vibration response of sandwich plate with nano-composite core and smart magneto-strictive face sheets. Composite core is reinforced by carbon nanotubes (CNTs) and its effective elastic properties are obtained by the rule of Mixture. Terfenol-D films are used as the face sheets of sandwich due to magneto-mechanical coupling in magneto-strictive material (MsM). In order to investigate the magnetization effect on the vibration characteristics of sandwich plate, a feedback control system is utilized. Also the sandwich plate undergoes the follower forces in opposite direction of x. Based on energy method, equations of motions are derived using Reddy’s third order shear deformation theory, and Hamilton’s principle and solved by differential quadrature method (DQM). A detailed numerical study is carried out based on third-order shear deformation theory to indicate the significant effect of follower forces, volume fraction of CNTs, temperature change, core-to-face sheet thickness ratio and controller effect of velocity feedback gain on dimensionless frequency of sandwich plate. These finding can be used to automotive industry, aerospace and building industries. تفاصيل المقالة
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        3 - On the dynamic stability of a flying vehicle under the follower and transversal forces
        Omid Kavianipour Majid Sohrabian
        This paper deals with the problem of the instability regions of a free-free uniform Bernoulli beam consisting of two concentrated masses at the two free ends under the follower and transversal forces as a model for a space structure. The follower force is the model for أکثر
        This paper deals with the problem of the instability regions of a free-free uniform Bernoulli beam consisting of two concentrated masses at the two free ends under the follower and transversal forces as a model for a space structure. The follower force is the model for the propulsion force and the transversal force is the controller force. The main aim of this study is to analyze the effects of the concentrated masses on the beam instability. It is determined that the transverse and rotary inertia of the concentrated masses cause a change in the critical follower force. This paper also offers an approximation method as a design tool to find the optimal masses at the two tips using an artificial neural network (ANN) and genetic algorithm (GA). The results show that an increase in the follower and transversal forces leads to an increase of the vibrational motion of the beam which is not desirable for any control system and hence it must be removed by proper approaches. تفاصيل المقالة