NewsAnalysis: BLAST DESIGN  
Analysis Tools Spur Opportunities  
for Blast-Resistant Glass Design  
he 1999 bombing of the Alfred  
P. Murrah Federal Building in  
Oklahoma City did to blast-re-  
sistant glazing what 1992’s Hurricane  
Andrew did to hurricane glazing. Both  
events brought awareness to how im-  
portant glass products are in protec-  
T
tive glazing. Each product type fulfills  
a unique purpose and each has distinct  
requirements. While building codes,  
for example, mandate the use of hur-  
ricane-rated products in designated  
locations and applications, blast-re-  
sistant products are primarily govern-  
ment driven.  
And blast designs are becoming  
more and more complex. Projects are  
more advanced today than in the past,  
and that can bring challenges for those Thanks to advances in products and technologies, glass can be used  
involved.In many cases,a blast consul- extensively in blast-designed projects, such as Vandenberg Hall at the U.S. Air  
tant can help.  
Force Academy in Colorado Springs, Colo.  
According to Carrie Davis, proj-  
ect engineer/practice leader and a ucts and technologies will still require  
principal of Protection Engineering some blast testing for validation.  
Grosze says there was a time when  
the architectural team wanted to min-  
“FEA can be more efficient cost wise imize glazing because it was the weak  
Consultants in Austin, Texas, product  
technology and analysis techniques than live testing, but you still have to point in the design.  
have improved. These have helped in- have validated test data,” she says. “But things have evolved because ar-  
crease the use of glass in blast designs. According to Rob Grosze, vice presi- chitects want attractive buildings. That  
Twenty years ago, a custom façade dent of operations for contract glazing evolution has been in the engineering  
would require a blast test,” she says. firm Physical Security LLC in Besse- and having the ability to model and  
Now we can run finite element models mer, Ala., there’s a shortage of those in analyze something before it’s built,” he  
for complex glass facade systems and the industry who truly understand a says.“The advances in computers have  
quickly determine if schematic designs blast façade and how it works with the allowed us to run simulations of the  
are feasible and economical for blast structure.  
loads.” “There are so many people who’ve wall and the structure work together.”  
Finite element analysis (FEA),for ex- tested a product, but tested it at a very He continues, “If the engineering is  
blast events and understand how the  
ample, is a computerized method used specific load, such as in the hurricane done right up front, for the guys in the  
to predict how a product will react in market where you test the product and field,[a blast project] is not much differ-  
real-world conditions such as a blast. [once approved] can use it in the given ent than any other commercial system.  
Davis says that, with the advances in application,” he says. “The blast-resis- The goal is to bring everything together  
design tools, blast-testing is not always tant market isn’t that easy. Just because to minimize the impact on field labor,  
necessary.  
you’ve tested one size doesn’t mean you where there’s already such a shortage.We  
quested.”  
However, Davis adds that new prod- stands these dynamics.”  
Analysis is being more widely re- can make it smaller or bigger. There’s don’t want to put the extra burden there.”  
still a need for an engineer who under-  
Tanya Dolby, product engineer, pro-  
tective glazing products with Kawneer  
36  
USGlass, Metal & Glazing | June 2017  
www.usglassmag.com  
Co. Inc., says it’s important to remem- companies begin to explore opportuni- threat, [blast-resistant projects] aren’t  
ber that each blast project is unique. ties in blast-resistant design and instal- that different from what a typical glaz-  
What worked on one project may not lation,there’s a lot they will need to keep ing contractor does every day,” he says,  
work for another. An in-depth review in mind,given these products are differ- adding that advances in glass are also  
is necessary to determine the proper ent compared to traditional glazing.  
product application for each project,” “You have to look at the whole pic-  
allowing architects to design more.  
“We’re doing sizes bigger today than  
she says.“It’s pivotal to provide as much ture,”says Davis.“Blast load is only one we were ten years ago,” he says.“We’ve  
information as early as possible, such component of a bigger system design. progressed like the commercial market  
as the standoff, charge weight, pressure, It should be complementary to the rest and increased our maximum capaci-  
and impulse among other aspects. This of the design.”  
allows the manufacturer to select the Grosze adds,though,one key consid- ufacturers and fabricators who have  
correct product initially to prevent inef- eration is working with knowledgeable stepped up and increased their quality,  
ficiencies and additional costs. A small suppliers. capacity and capabilities. We’re only  
change can have a large effect.” “If they have the right supplier and bound by the glass we can purchase.”  
ties,and that’s a credit to the glass man-  
As awareness increases and more engineer and truly understand the  
—Ellen Rogers n  
www.usglassmag.com  
June 2017 | USGlass, Metal & Glazing  
37  

USGlass
© 2017 Copyright Key Communications Inc. All rights reserved. 
No reproduction of any type without expressed written permission.