Passive Fire with Fire Rating
Posted on 9th January 2024 at 17:10
We have continued to develop calculations to allow engineers to calculate load bearing member capacity under fire conditions for light gauge steel members. Now we have added tools to calculate thermal induced bowing based on hot and cold flange temperatures.
Using methodologies from Test Houses testing 4.0m high panels who then acredit panels upto 12m using techniques and calculations they have devloped to extrapolate based on hot and cold flange temperatures and Euler lengths as maximum heights we have been able to add calculations to allow us to calculate the expected addtional deflection due to these thermal changes coupled with the axial loads applied as load bearing studs.
Coupled with deflection limits derived from testing panels in furnaces and test analysis providing hot and cold flange temperatures we are able to produce realistic calculations for expected performance of load bearing panels under fire load to BS 5950-8, Annex A and EN 1993-1-2 Clause 4.2.4 Critical Temperature, Table E.1.
It can be seen from above that we have used hot flange temperatures of 583 degrees celcius and 544 degrees celcius for the cold flange, along with a deflection limit of H / 35 based on 3m high and 86mm deflection.
There is, obviously, more to these calculations than this, but thes are effectively the headline figures. To know more about this or review a worked example please arrange a call or Video meeting with us via the Contact Page.
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