Facade/Curtain wall Mullions

[ryan_struct]

Dear Engineers,

A question to facade engineers/curtain wall specialists.
I’m curious to know about the system design. Can someone here through some light on mullion system design.
How you design a new profile. What all criteria you check while designing?
What checks you do for the new designed profile?
Which finite element program you use for the system design?

Thanks in advance.

 

[klaus.]

I guess most facade companies have their own design process.....
But generally you can design facade structure the same as any other structure...
We use mostly Dlubal RFEM

 

[jjl317]

In my experience from standard stick-built through custom unitized curtain walls, I have found that there are a large number of factors must be considered when designing new profiles. Architectural, air/water management, thermal performance, installation issues, fabrication/connection issues, seismic/building movements and glass connections/engagement are all potential factors to be considered, and in many cases, the structural performance is one of last items to be confirmed. In terms of analysis, for aluminum extrusions (very common/typical in curtain wall in the US), custom shapes are generally used, which require developing allowable members capacities based on the Aluminum Association ADM for each extrusion, considering all relevant failure modes, (buckling, LTB, etc.). Once the allowable capacities are developed, the individual members can be analyzed through any number of standard techniques. Additionally, the deflection limits are specialized, due to requirements of supporting the glass appropriately, while maintain air/water tightness. In my experience, finite element programs are seldom required.

Hope this helps