The largest wood beams ever tested are being studied at the US Forest Service Forest Products Laboratory (FPL) in Madison, Wis. If you’ve ever wondered what upwards of 80,000 pounds of load looks or sounds like when applied to a 72-foot-long, 6,000 pound wood beam, now’s your chance. Bam!
Glued laminated (glulam) timbers are a manufactured wood product composed of layers of sawn lumber glued together. Glulam beams are typically used as main structural members and make for both an aesthetically pleasing and structurally sound option.
The FPL is one of the few locations worldwide that has the capacity to test such large wood specimens. And as FPL engineer Doug Rammer explains, that capability is key to determining their strength.
“To get a realistic measurement of how much load these large beams can withstand, it’s important to test them at their actual size,” Rammer says. “Larger beams fail at a lower stress when compared to smaller replicas, so full-scale testing is necessary to obtain accurate data.”
Using the engineering mechanics area of the new Centennial Research Facility, FPL researchers are working in cooperation with the University of British Columbia on these tests. The results will influence building code requirements for the use of glulams in the United States and Canada.
By James T. Spartz