Resonance Amplification of Dynamic Response of Structures

By |2020-03-19T10:27:31+00:00March 19th, 2020|Tutorials|

Prof. Pennung Warnitchai of Asian Institute of Technology (AIT), Thailand explains the phenomenon of resonance amplification of dynamic response of structures using a simplified mode (often referred to as the Boss Model). The resonance is a phenomenon resulting in large amplification of oscilations which occurs when the frequency of a periodically applied force is same as the natural frequency of the system on which it acts. When an harmonic force is applied at a resonant frequency of a system, it will oscillate at a higher amplitude than when the same force is applied at any other frequency. [...]

Structural Analysis: Are We Relying Too Much on Computers?

By |2021-01-07T09:21:21+00:00March 17th, 2020|Structural Engineering|

An interesting two part series of articles authored by Prof. Dr. Graham Powell. Prof. Powell is Professor Emeritus of Structural Engineering at the University of California at Berkeley. Over his career, Professor Powell has developed, or supervised the development of, several computer programs that have been used widely in research and industry. He currently works as a consultant to Computers and Structures Inc., developing and supporting the CSI PERFORM computer program. Professor Powell may be reached at

Significance of Soil-Structure Interaction in Seismic Response of Buildings

By |2020-03-15T13:56:08+00:00March 12th, 2020|Structural Engineering|

In current design office practice, a commonly used modelling assumption is that the base of a building structure can be idealised with fixed support conditions, thereby neglecting any effects from soil-structure interaction (SSI). Various recent studies, however, have shown that the explicit consideration of SSI effects in seismic analysis of buildings structures may significantly affect the predicted seismic demands and resulting structural performance. This study addresses some key issues and practices in the area of SSI and its effects on the dynamic response and seismic performance of buildings. It is also intended to demonstrate the significance of considering SSI effects [...]

Torsional Irregularity Check and Accidental Torsion

By |2020-03-12T07:23:09+00:00March 12th, 2020|FAQs|

Question: I am currently working in a Consultancy firm in Islamabad and have few queries regarding torsional Irregularity explained as follows: 1) As per UBC torsional irregularity exists if "Maximum story drift, computed including accidental torsion, at one end of the structure transverse to an axis is more than 1.2 times the average of the story drifts of the two ends of the structure". In our general practice, we compare the ratio of maximum displacement to average displacement with 1.2 to confirm if the torsional irregularity exists or not. But as per the above stated UBC Statement, we should [...]

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