التحليل الطيفي للاهتزازات العابرة المتتالية

  Any motion that repeats itself after an interval of time is called vibration or oscillation. The quality of ride of an automobile, the motion of an airplane's wings and the swaying of a large building due to wind or an earthquake are typical examples of vibration. The theory of Vibration deals with the study of oscillatory motions of bodies and forces associated with them. Vibration can be harmful and should be avoided, or it can be extremely useful and desired.

  Vibration is modeled mathematically based on fundamental principles, such as

Newton's law, and its analyzed using results from calculus and differential equations. In addition, information and methods that are given in the useful designing a particular system to have a specific response.

  The physical explanation of the phenomena of vibration concerns the interplay between potential and kinetic energies. A vibration System must have a component that stores potential energy and releases it as kinetic energy in the form of motion of the mass. The motion of the mass then gives up kinetic energy to the potential energy storing device.

  In many practical situations, the dynamic excitation is neither harmonic nor periodic. Thus we interested in studying the dynamic response of Single Degree of Freedom (SDF) system to excitation varying with time. This result is used to study the response of the systems to Step Force, linearly increased force and step force with finite rise time. These results demonstrate how the dynamic response of the system is affected by the rise time.

  In our project we will conduct a research in order to determine the effect of base motion upon the simple mass system an d its response. Different excitation forces are applied to the system in order to differentiate between their effects. The aim of these analyses is to eliminate the effect of the harmful vibrations to systems such as those in vehicle system 2nd its occupational drivers, drivers whom exposed themselves to vibration for a long time, which might cause bad effects to their health and low back pain. So in this project we will go over the effects of the successive force in single degree of freedom system and the base excitation to a second degree of a freedom system.