Open AccessTO STUDY THE EFFECT OF CENTER OF MASS, CENTER OF RIGIDITY, CENTER OF STRENGTH OF A BUILDING ON A TORSIONAL MOMENT USING NONLINEAR TIME HISTORY ANALYSIS
Author(s) -
Prof. Syed Farrukh Anwar,
Mr. Mohd Zaker,
Md Shahabuddin
Publication year - 2016
Publication title -
zenodo (cern european organization for nuclear research)
Language(s) - English
DOI - 10.5281/zenodo.161676
Subject(s) - center (category theory) , nonlinear system , center of mass (relativistic) , moment (physics) , rigidity (electromagnetism) , structural engineering , physics , engineering , mechanics , classical mechanics , chemistry , quantum mechanics , energy–momentum relation , crystallography
Modern architectural design more often than not deals with irregular structures. In these structures, the torsion phenomenon can induce significant stresses, especially in the case of seismic motion. The seismic response of an asymmetric building subjected to ground motion tends to be significantly stronger due to torsional effects. These effects arise from the non uniform distribution of mass, the stiffness, the strength and the torsional components of the ground movement. Torsion has been the cause of major damage to buildings subjected to strong earthquakes, ranging from visible distortion of the structure to structural collapse. It occurs under the action of earthquake forces when the center of mass of the building does not coincide with the center of rigidity. The distance between them is called eccentricity. Lateral force multiplied with this eccentricity causes a torsional moment that must be resisted by the structure. In theory, reducing the distance between the center of mass and center of rigidity should minimize the torsional effects. Six models were considered to test the effects of torsion and rotation wherein, models one, five and six shared column size. Model one served as the basic model while model five had a base isolator incorporated in it and model six implements shear walls. Models two, three and four are similar to the basic model except for the column sizes with the redistribution of strength and stiffness and have no special parameters applied. In this project, it has been evaluated that it is possible to effectively reduce torsional and rotational effect within an irregular building up to 15 stories. Although the base isolator provided the best resistance to deforming forces over the structure, it is worthwhile to note that just the configuration of centers provides an acceptable levels of resistance with significant reduction in cost and is far more feasible in many parts of the world. Keywords: Center of Mass, Center of Rigidity, Center of Strength, Torsional Moment, Nonlinear time history analysis