REACTION OF VARIOUS VIBRATIONAL MOTIONS

Structural dynamic is a mandatory graduate level course for structural engineering student all around the world. In civil engineering buildings are mostly designed based on prescriptive methods of standard codes. Usually loads on these buildings are of low magnitude which results in elastic structural behavior. However, strong loads such as a sudden earthquake will lead the building beyond its elastic limit. Generally 4 kinds of earthquake ground motions are considered such as Fault Normal, Fault Parallel, Near Fault and Far Fault components.

In the current study the performance of a building in a single degree of freedom system is investigated under different ground motions such as Fault normal and Fault parallel component of the ground motion by dynamic time history analysis method and the analysis is done in the SEISMOSTRUCT software developed by the SEISMOSOFT Company.

The Acceleration, Velocity and displacement curves have been drawn for both Fault Normal and Fault Parallel component of Far Fault and Near Fault ground motion. The values of acceleration, velocity, displacement have been found in every 0.005 seconds, also the values of Peak Ground Acceleration, Peak Ground Velocity and Peak Ground Displacement has been determined for both components.

The values of PGA, PGV, PGD obtained for fault normal component are higher than the values obtained for the fault parallel component of the ground motion, also the frequencies of fault normal component of ground motion are more than that of the fault parallel component of ground motion.

The values of Peak Ground Acceleration, Peak Ground Velocity and Peak Ground Displacement of Fault Normal and Fault parallel components don’t differ much for Far Fault earthquake ground motions, but they differ much for Near Fault Earthquake ground motions. The reaction spectrum curves are different for each kind of earthquake ground motions, hence it means that the building have different reactions to each kind of earthquake ground motions.