I’ve posted a new web calculator tool related to structural fire safety to calculate the lumped temperature of steel under fire conditions. The tool has the ability to input parameters for steel, select a standard fire time-temperature curve (ISO or ASTM), and choose unprotected or protected steel. The tool is based on the equations from the textbook by A. Buchanan, Structural Design For Fire Safety, and is available here:
I hope you find the calculator useful, and I will continue to add web tools for fire protection engineering calculations. I will be adding a more detailed explanation and equations to the steel heating calculator page in the near future as well as releasing the source code.
Please let me know if you find any bugs, would like to give feedback on this tool, or have a request for another web calculator! The next web tool will be a calculator to give results from the Heskestad flame height and centerline temperatures.
In August of 2009 in Truckee, CA, a man was cooking on a stove when the pan caught fire, activating the fire sprinklers. Upon activation of the sprinklers, a violent explosion occurred which resulted in 1 death and 4 burn injuries to the family.
I came across this copy of a report (from the IAFSS mailing list) which details a report of a cooking fire turned explosive when the sprinklers were activated. Allegedly the propylene glycol used in the fire sprinkler system as an antifreeze aided in the explosive event, and another case is cited in which the antifreeze ignited and assisted in growing the fire from its ignition source.
While I have taken a few courses in fire sprinkler systems, I am not extremely familiar with the flammability of antifreeze such as propylene glycol, but allegedly the atomization of the droplets causing the liquid to become flammable was the cause of this explosion. More flammability and MSDS hazard info is cited in the report.
The report presents many questions at the end which would be useful in quantifying the relationship of the antifreeze in this case, especially since (to my understanding) propylene glycol is the most widely used antifreeze in sprinkler systems. I look forward to finding out more about this topic, and I think it’d be a great research project for a student or research firm to take on.
Every once in a while, someone makes an impression on you that lasts for a lifetime. It sticks with you every single time. This is one of those, although a bit on the nerdy side, it is one that can change the way you present information in a very meaningful way.
I was once sitting at the NIST annual fire conference, going about my business, and someone working on a project regarding the structural response aspect of buildings on fire showed a video in their presentation. No big deal, right? Normally, we get cool fire videos, then some plots, and so on. Sometimes the plots are interesting, sometimes they are default from Excel with the ugly legend and all – with no story to tell.
But not this guy. He showed a video with real-time plots superimposed over the video showing the exact real-time structural response of the structure overlaid on the video in a plot. “AMAZING!” I thought. And it stuck with me. A useful way to convey synchronous information. People love videos, why not tell the qualitative AND quantitative story at the same time?
So I started working in grad. school on fire problems, and naturally, soon thereafter, I was scheduled to give a presentation. As most of my real creative coding and writing work happens of hours between the hours of 1 AM and 6 AM, I wanted to make this happen. I REALLY wanted some real-time plotting action in my presentation. No Excel templates for me! So I stayed up for a couple nights and worked on a way to use MATLAB to make this plotting dream a reality: I worked on importing videos, messing with frame rates, tons of images, and so forth. And soon thereafter, it happened. I had a working script.
I used it to show plots of large-scale fire tests with actual and predicted flame heights vs. time as seen here:
And I used the script to show the predicted flame heights on a small-scale test in an amazing way that just about anyone can relate to, fire-crazed scientist or not:
From anyone who has seen the videos firsthand, the response has been amazing. This is a great teaching and communication tool, and surprisingly enough, I haven’t found any existing program or tool that does this. And so I am sharing the videos and script here for anyone to use to better convey information.
My next steps are: 1) to convert the script to Python (since I am now almost exclusively using Python+numpy+scipy for my graduate research and daily work instead of MATLAB, and 2) to make the script into a cross-platform and easy to use tool.
I’m providing the code in its raw and uncommented and unedited form. It generates a number of images with plots superimposed on them, and then it is trivial to use a program to stitch them together into a video. I used Quicktime’s built in method. Sorry, too much current work going on finishing my MS thesis and Master’s degree to clean up the code, but it’s a brutal use of the “release early, release often” ideal! Hopefully someone can make some use of it.
