5 MACHINES THAT SIMULATE NATURAL DISASTERS

5 Machines that Simulate Natural Disasters
By Erin McCarthy, Mental Floss, 12 January 2015.

Natural disasters can strike at any time, causing huge loss of life and billions of dollars in damage. Scientists are using these machines to help us be better prepared.

1. UC San Diego Jacobs School Shake Table

If you were the kind of kid who liked to build houses out of blocks then knock them down, consider enrolling or getting a job at UC San Diego, where scientists do that kind of thing pretty often: They build full-sized structures on top of a 25 x 40-foot table - the largest in the country - then shake it to see how well different types of construction, various kinds of materials, and retrofits to existing buildings might stand up in a quake.

The US$5.9 million hydraulically-driven machine can vibrate at 6 feet per second with a maximum force of 4.2 Gs. The machine has been used to test everything from “wind turbines, to masonry, wood-frame and precast concrete buildings, as well as non-structural building elements, such as stairs, elevators and even hospital equipment,” according to a school press release. You can watch the table shake a 4-story 1920s-style building retrofitted with cross-laminated timber above.

2. Iowa State University Tornado Simulator

This first-of-its-kind machine, which opened in 2004, consists of two parts: a huge cylinder, suspended from a 5-ton crane, that contains a 6-foot-wide fan; and a test bed that can be raised and lowered. Scientists construct model towns on the test bed, then fire up the fan - which creates a tornado-like vortex with 55mph winds - and move it over the “town.” The machine’s sheer size allows scientists to build bigger model structures, creating a more realistic version of what might happen in an actual tornado.

3. and 4. Oregon State University’s Tsunami Basin and Large Wave Flume

The O.H. Hinsdale Wave Research Laboratory at Oregon State University has a pair of wave-generating machines. The 160-foot-long, 87-foot-wide, and 7-foot-deep Directional Tsunami Wavemaker is equipped with electric motors and uses pistons to push out 29 waveboards to create tsunami-like waves.

The Large Wave Flume (the largest in North America) measures 342 feet long, 12 feet wide, and 15 feet deep, and can create waves 5 feet high. In both structures, scientists study the effects of the kinds of waves seen in nature on models of everything from buildings to telephone poles to levees. Recent research done using the machines showed that coastal forests might help mitigate tsunami damage.

5. Florida International University’s “Wall of Wind” Hurricane Simulator

This massive, US$8 million machine consists of 12 fans, each 6 feet in diameter and 700hp, that can generate winds up to 157 mph - the kinds of winds you’d see in a Category 5 hurricane. At peak flow, the system pumps as much air as 7650 leaf blowers. In one demonstration, the FIU team built two structures: One built to code before 1992's Hurricane Andrew, and one built with codes created after. According to the Miami Herald,

The first things to go were roof shingles but pre-Andrew designs, rated for just 60 mph, held up nearly as well as heavier products rated for 130 mph. Half of the supposedly stronger shingles began peeling away as the digital wind gauge hit 109 mph, just Cat 2 strength. But as the wind increased, there was no comparison between old and new. At Cat 3, the older design lost half the tar paper intended to keep out rain. At Cat 4, a whole section of thinner plywood sheathing began buckling furiously, then flew off in a flash.

Top image: The Large Wave Flume at the O.H. Hinsdale Wave Research Laboratory. Credit: Oregon State University.

[Source: Mental Floss. Edited. Some links added.]