AN INVESTIGATION OF THE DYNAMIC RESPONSE OF THREE STORIES BUILDINGUSING NONLINEAR SPRING

Abstract

A novel analysis of three stories - building, using finite element method via ANSYS software with nonlinear spring is presented. The investigation is carried out to show the natural frequencies and the response of the building under nonlinear effect of spring. The free and force vibration of a building with a non-linear spring–mass system has been investigated. The non-linear spring appears in the form of quadratic, exponential and logarithmic equation. The transient and modal solutions are done by using ANSYS to the non-linear system. The results of the linear frequencies and the response matched well with those obtained in the mathematical model. Subsequent non-linear study indicates that there is a pronounced effect of the non-linear spring and its mass. The exponential equation of nonlinear stiffness gives the highest magnitude of three modes of the natural frequencies with 0.0371% ,0.014% and 0.07% respectively of other cases of form equation (quadratic and logarithmic).