Random Vibration of Elastic Systems

Understanding random Vibration signals

Analyzing Random Vibration Fatigue

Determining the fatigue life of parts under periodic, sinusoidal vibration is a fairly straightforward process in which damage content is calculated by multiplying the stress amplitude of each cycle from harmonic analysis with the number of cycles that the parts experience in the field. The computation is relatively simple because the absolute value of the vibration is highly predictable at any...

Disordered Systems and Optimization : Elastic Lines and Random Magnets

The behavior of many physical systems, especially at low temperatures, is governed by the properties of their ground states. Usually it is not a trivial task to find the ground state configuration, especially in the case of disordered, complex systems. However, with quenched disorder this can be often done efficiently with the means of combinatorial optimization. In this thesis we study two suc...

Nonlinear Forced Vibration Analysis of Elastic Structures by Using Parallel Solvers for Large-Scale Systems

Geometrically nonlinear forced vibrations of three dimensional structures, due to harmonic excitations, are investigated in the frequency domain. Structures of elastic materials are considered and the discretized equation of motion is derived by the finite element method, using Elmer software. The shooting and the continuation methods are applied to the resulting large scale FEM system by using...

Gyro-elastic beams for the vibration reduction of long flexural systems

The paper presents a model of a chiral multi-structure incorporating gyro-elastic beams. Floquet-Bloch waves in periodic chiral systems are investigated in detail, with the emphasis on localization and the formation of standing waves. It is found that gyricity leads to low-frequency standing modes and generation of stop-bands. A design of an earthquake protection system is offered here, as an i...