In this paper, vibrations and bifurcation of a damped system consists of a mass grounded by linear and nonlinear springs and a nonlinear damper is studied. Nonlinear equation of motion is derived using Newton’s equations. Approximate analytical solutions are obtained using multiple time scales (MTS) method. For free vibration, the approximate analytical results are compared with the numerical i...

Theoretically it was determined that changing longitudinal rigidity of waveguide the longitudinal vibrations amplitudes are increasing. The cross-section of waveguide is decreasing from the generating point towards its free end. Experimental results show that the free end of the waveguide is influenced by longitudinal vibrations only, which could be used for blood vessels cleaning.

~This report presents the first stage of an investigation of the response to random noise of a stiffened cylinder, representing an aircraft fuselage, including an analysis of the lower modes of such a cylinder. Preliminary investigations suggested that assumptions and approximations which are valid for the uniform, i.e., unstiffened, shell are not necessarily valid for a shell with heavy stiffe...

Arterial bleeding into a free space is known to cause local vibrations in tissue. To study the effectiveness of utilizing these tissue vibrations in localizing the site of arterial bleeding, we have developed an algorithm for ultrasonically imaging these tissue vibrations. Simulation results indicate that our algorithm can correctly detect vibrations in the presence of pulsatile wall motion, bl...

A complete solution is obtained for nonaxisymmetric resonant vibrations of a free cylinder or disk involving infinite sums. For axisymmetric longitudinal vibrations an alternative to previous solutions is included. In principle, the solutions satisfy exactly the stress-free boundary conditions, in contrast to the approximate bending-mode solutions due to Pickett or approximate solutions based o...

In this paper, the nonlinear free vibrations of thin symmetric and non-symmetric cross-ply composite plates subjected to biaxial initial stresses are investigated. Because of their excellent properties such as specific strength and specific stiffness, composite plates have wide applications in aerospace and mechanical structures. Based on Von-Karman's strain-displacement relations and using Gal...