Semester

Spring

Date of Graduation

2014

Document Type

Thesis

Degree Type

MS

College

Statler College of Engineering and Mineral Resources

Department

Mechanical and Aerospace Engineering

Committee Chair

Nithi T. Sivaneri

Committee Co-Chair

Roxana Cisloiu

Committee Member

Victor Mucino

Abstract

Applications of axially-moving beams are found in earthquake engineering, robotic arms, conveyor belts, etc. Previous studies have shown that the amplitude of lateral vibration of moving beams is 40 percent higher than that of non moving beams. In this research a numerical model based on the finite element method is done to reduce the excess vibrations caused by the axial oscillation of the beam. A computer code is written in MATLAB to accomplish this.;The vibrational amplitude of composite moving beams is reduced by means of an active vibration control technique that employs the piezoelectric effect. Piezoelectric sensors and actuators are added to the beam to sense and control the vibrational response of the moving beam. The sensors and actuators are made to communicate with each other using negative velocity feedback control. Classical laminate plate theory (CLPT), first order shear deformation theory (FSDT) and higher order shear deformation theories (HSDT) are considered for the analysis of composite beams. A consistent formulation is used to reduce the composite plate theory to beams. The governing equations are obtained using variational principles. The displacement constraints are applied through Lagrange multipliers. An over hanging beam is considered for the analysis purpose. First bending mode shape is taken as the initial shape of the beam. Newmark's time integration scheme is used to generate the controlled response of the beam. The feedback gains are altered to have a desired control at certain time.;Results are presented in terms of tip deflections. The damped response of the CLPT is compared with that of FSDT and HSDT for a specific gain. A parametric study is conducted by varying the frequency of axial oscillation and considering different laminates.

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