laminated glass vertical panels

[gazibu]

I have a laminated glass panel wall that is spanning vertically 6 ft and fixed at the base. Typically I have seen modulus of rupture values of 24000 psi for glass panels (tempered/laminated).Also typically a factor of safety of 4 is used to obtain the allowable bending stress = 6000 psi.Does any one know if a lower F.S. can be used or if for laminated glass a higher Mod of rupture can be used? In IBC 2003 ch. 24 a F.S. of 4 is recommended for Guard rail etc. but this is not a guard rail.it separates 2 areas on the same level.

 

[Lion06]

I would check out ASTM E-1300. You can use a higher allowable stress for tempered glass than for annealed. Right around 10ksi is coming to mind, but I haven't look at it in a while. Laminated glass requires the use of a load duration factor since the interlayer in laminated glass creeps significantly, only very short duration loading can count on any significant composite action. Again, check out ASTM E-1300.

 

[gazibu]

I am somewhat familiar with ASTM E1300. Do you know where it can be downloaded or viewed without having to purchase it?
Thanks

 

[Lion06]

I don't know if it can be.

 

[maramos]

The 10.6ksi that structural EIT is talking about is for edge stress not surface stress which is what will govern in your analysis.

Allowable surface stress is 13.5ksi (tempered Glass)per E1300-07
Allowable edge stress is 10.6ksi ((tempered Glass) per E1300-07

 

[gazibu]

Are you implying that the 6000 psi/ 6 ksi value I have been considering is way too conservative versus your 13.5ksi? also is this value also applicable to laminated glass?

 

[Lion06]

That's correct maramos, thanks, I just checked it.

gazibu-
That value is only applicable to tempered glass, annealed and heat strengthened have different values. Additionally, that assumes a 3-s load duration and you have to adjust the allowable based on your actual load duration.

 

[gazibu]

When you say load duration assuming the load in question is wind ,how does the duration come in to play?