Structural Madness

Uploaded a new video on generating a response spectrum. I am also sharing a spreadsheet which will help you generate your own response spectra for the time histories you select. Feel free to browse through and let me know if you found this useful.

Generating a Response Spectrum from acceleration time history Hello everyone. In this video I am discussing how a response spectrum is generated using an acceleration time history. I also briefly discuss about displacem...

On June 24th, at 1:25 AM the Champlain towers south located in the town of surfside collapsed dramatically. The reason behind this collapse was still unknown, but after spending a lot of hours reviewing drawings, collapse pictures as well as reading through the news article, it was possible to potentially point out the reason behind this collapse.

I was able to put together a complete analysis behind the potential reasons of the Champlain towers collapse. Head over to the video link to understand the collapse in detail.

Reasons behind Surfside Building - Champlain Towers South - Collapse : A Structural Engineers Review On June 24th, at 1:25 AM the Champlain towers south located in the town of surfside collapsed dramatically. The reason behind this collapse was still unknown...

Check out our new video Lecture on Building Torsional Irregularity check per ASCE 7-16! This video is presented with in-depth explanations of different code sections per ASCE.

Torsional Irregularity Check Per ASCE 7-16 Torsion in a building can affect building performance in many ways. It not only adds complexity in predicting building behavior but it also reduces the ducti...

In this post, I am not asking to reduce the R factor for structural systems, I am discussing why to completely eradicate R and move on to a different method of structural analysis. It is not that our current approaches are bogus, but they are definitely lacking when we talk about achieving seismic reliability. This typically happens when we try to dumb down the complexity of structural dynamics into simple mathematical functions, that try to represent realistic conditions. This worked great when we didn't have resources at hand. That is why there is a probability of collapse associated with any seismic event.

But with the advancement in technology, I think we can deal with more reliable seismic analysis, even if it is complicated. Because that will help us in achieving the "confidence factor" in building design which will in turn help and reduce the probability of collapse without significantly impacting the cost of structures. I think it is high time when we think about displacement-based design coupled with resiliency, capacity-based approach, and element-based ductility.

Why Should we Drop R?(Force Reduction Factor or Response Modification Factor) Jinal Doshi, P.E.- Project Manager at DCI Engineers, USA Seismic design of structures is seen as one of the most challenging parts of structural engineering. It may not seem as difficult once you start learning, or even if you have practiced it for some years. It may just appear to be some simple ma...

I know it has been a long time since I posted anything. But here is a new answer!

What characteristics of steel enable it to replace cast iron and wrought iron as structural materials during the latter part of the 19th ... Jinal Doshi's answer: Ductility, reliability and little less responsive to corrosion. These two properties have significantly changed the use of wrought iron to structural steel. There are many more but I will focus on these two at the moment. Wrought iron was not pure and did not have a good ba...

We got one very interesting question on our latest video. If you have any, no matter how trivial it is, feel free to ask me. You never know when can we open our eyes to new results and building behavior.

Check the video below:
https://www.youtube.com/watch?v=ujzFcL2ILk8

If you are interested in time history analysis and performance based seismic design then this video is for you. If you want to know the limitations of modal analysis and response spectrum analysis for tall buildings then do watch this video upload by us. You can as many questions as you want on this topic and I will be happy to answer them all!

Thank you!

Impact of Ground motion frequency content on seismic response of a Tall Building Seismic Excitation is not only random in nature but it also impacts the way building responses to these natural random excitations. Modal analysis is based o...

One of the most amazing cities of 21st Century! Veiws from One World Observatory are just Breathtaking!

One Project, 20 months of design. This is the most complicated project that I have ever worked on through my career. I am feeling proud and happy to work on this from Performance Based Seismic design objective.

The complicated towers added challenges to bring on board innovative solutions that helped in stability of towers from seismic perspective.

Absolute master piece by Frank Gehry.

The Grand Frank Gehry Groundbreaking

If you want to understand the dynamics of structures properly, refer to these two links right after one another. Let us have a healthy and engaging discussion after that.

Lesson 1: https://www.thestructuralmadness.com/2018/09/what-does-opera-singers-and-structures.html

Lesson 2:
https://youtu.be/A3DSsHzEg40

You can comment to ask questions in the blog or on Facebook. Note that the older comments have been deleted as Google+ is going away.

Also, would you like to have a live video session to discuss more structural engineering? If yes, do let us know.

What do Opera singers and Structures have in common? Resonance, Dynamic amplification factor, Damping, Fundamentals of vibration, Response of undamped system, response of damped system,

Performance-based seismic design is gaining everyone's attention. This complicated design process has many thought-provoking philosophies as well as scientific research that leads to a more accurate design of a building. It not only helps in reducing the cost of the construction but also leads to a more confident building design.

I pinned down a small article on PBD simplifying many complicated terms so that everyone can understand why it has become so much more popular in the recent decade. Being involved in such rigorous analysis has taught me, how to thoroughly understand building behavior.

Why Performance-Based Seismic Design? Earthquakes can easily disrupt a city in a matter of seconds. In the early 20th century earthquakes were not properly understood and there were not many building codes or even documentations that could help engineers in designing buildings.

I just finished making a new video on Torsional irregularity. I promise there are no equations except conceptual discussion. I hope you enjoy the gummy bears in this video.

You can discuss and express your concerns as for how you think torsional irregularity effects the seismic performance of the system.

Thank you for Watching everyone.

What is Torsional Irregularity in a building? Torsional irregularity in a building occurs when the center of mass of a building and the center of rigidity does not line up. This creates non-uniform ducti...