Elastic instabilities in polymer tube of resonant sound absorbers under hydrostatic pressure

The solution of the problem of hydrostatic compression of an elastomeric tube is based on the nonlinear theory of elasticity for incompressible materials employing the method of Ritz variations and the ANSYS finite-element solutions. The main purpose of the investigations is to obtain the loading diagrams in the total range of elastomeric tube thicknesses, without any kinematical and physical restrictions on the behavior of elastomer, e.g., neglecting the Kirchhoff and Timoshenko hypotheses or Hooke's la

Application of macro-fiber composite (MFC) as a piezoelectric actuator

The aim of the present work is to investigate the use of Macro Fiber Composite (MFC) actuator for modal analysis of composite plate. Efficiency of application of MFC as an actuator in comparison with the impact hammer, PZT actuator and modal shaker has been investigated. POLYTEC laser Vibrometer operating on the Doppler principle and measuring back-scattered light from a vibrating panel has been used to determine its vibration velocity and displacement. Modal analysis is subsequently applied to extract natural frequencies and mode shape

Elastic instabilities in polymer tube of resonant sound absorbers under hydrostatic pressure

The solution of the problem of hydrostatic compression of an elastomeric tube is based on the nonlinear theory of elasticity for incompressible materials employing the method of Ritz variations and the ANSYS finite-element solutions. The main purpose of the investigations is to obtain the loading diagrams in the total range of elastomeric tube thicknesses, without any kinematical and physical restrictions on the behavior of elastomer, e.g., neglecting the Kirchhoff and Timoshenko hypotheses or Hooke's la

DESIGN OF HELICOPTER ROTOR BLADES WITH ACTUATORS MADE OF A PIEZOMACROFIBER COMPOSITE

For reducing the vibration and noise of helicopter rotor blades, the method of their controlled twisting by using built-in deformation actuators is employed. In this paper, the influence of various design parameters of the blades, including the location of actuators made of a piezomacrofiber material, on the twist angle is evaluated. The results of a parametric analysis performed allowed us to refine the statement of an optimization problem for the rotor blades