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https://idr.nitk.ac.in/jspui/handle/123456789/17775
Title: | Dynamic Analysis of Composite Sandwich Beam Under The Passive, Semi-Active and Active Vibration Control Techniques |
Authors: | Suryarao, Nagiredla |
Supervisors: | Joladarashi, Sharnappa Kumar, Hemantha |
Keywords: | Finite element formulations;Sandwich beam;Magneto-rheological fluid;Viscoelastic material |
Issue Date: | 2023 |
Publisher: | National Institute Of Technology Karnataka Surathkal |
Abstract: | The present study is aimed at understanding the behavior of sandwich beams and the influence of vibration control methods on the dynamic response. The passive, semiactive, and active vibration control techniques are implemented on the sandwich beams. The present study developed a finite element (FE) formulation for the composite sandwich beam and utilized the Euler-Bernoulli's method for sandwich beam element and Lagrange's approach is considered to obtain the equation of motion (EOM). The FE formulation solution is validated using different case studies available in the literature. The validation process ensures that the developed model is accurate and reliable for predicting the dynamic response of sandwich beams. The study provides insights into the effectiveness of different vibration control methods and the impact of various parameters and boundary conditions on the dynamic response of sandwich beams. Viscoelastic materials can dissipate the vibrational energy in the form of heat when the structure undergoes cycles of deformation. For the passive vibration control of sandwich beam, two different viscoelastic materials and four different axial gradation configurations of viscoelastic materials are considered. The influence of viscoelastic material and boundary conditions on natural frequency, loss factor, and frequency response are investigated as a part of the initial study. Further, the influence of axial gradation configurations of the viscoelastic materials on the dynamic response is reported. Then, a comparison study of all configurations at different boundary conditions is discussed. The field-dependent magneto-rheological (MR) fluid is used for the semi-active vibration control of the sandwich beam. MR fluid comes under the category of smart materials, and it can transform its rheological properties when it is exposed to an externally applied magnetic field. This nature of the MR fluid provides additional stiffness and damping for the sandwich beam applications. The effect of combined damping due to composite facings and MR fluid on the dynamic response of composite sandwich beams is discussed. The static, free, and forced vibration analyses of the composite sandwich beam are extracted to understand the influence of various iv parameters on the static and dynamic response of the sandwich beam applications. A detailed study is conducted to evaluate the effect of composite laminate angle, magnetic field, and thickness ratio on the static deflection, natural frequency, loss factor, and frequency response. The influence of the magnetic field on the percentage of deviation in natural frequency, loss factor, and static deflection is also discussed. Further, the influence of MR fluid pocket configuration type on the dynamic response of the sandwich beam is presented. The configuration types include 1/4th, 1/2th, 3/4th, and the full length of the MR fluid pockets at different locations. In addition, a detailed study of the influence of each MR fluid pocket configuration type on the natural frequency, loss factor, and frequency response are presented for the clamped-free (CF), clamped-clamped (CC), simply-supported (SS), clamped-simple (CS) and simple-free (SF) boundary conditions. In addition, two different compositions of in-house MR fluid samples with 24 and 30 percentage of volume fractions of carbonyl iron (CI) particles are prepared. The influence of oscillating driving frequency, strain amplitude, magnetic field, and the percentage of CI particles on the rheological properties of the MR fluid samples are discussed. The properties of MR fluid samples are used in the numerical formulations to explore the influence of the iron particles volume percentage on the dynamic response of the MR sandwich beam. Further, the active vibration control technique is implemented in combination with passive and semi-active control techniques. The Proportional, Integral, and Derivative (PID) controller is developed to compare the transient response of the sandwich beam with the controller and without the controller. |
URI: | http://idr.nitk.ac.in/jspui/handle/123456789/17775 |
Appears in Collections: | 1. Ph.D Theses |
Files in This Item:
File | Description | Size | Format | |
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177155-177ME030-NAGIREDLA SURYARAO.pdf | 18.76 MB | Adobe PDF | View/Open |
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