The following essay is covered in The Conversation, an online publication.
Some of the most powerful hurricanes to ever hit land are being recreated in an airplane hangar. A test building can be shattered in the blink of an eye.
They don't have the power to keep up with nature.
The Wall of Wind test facility was inspired by Hurricane Andrew, which devastated South Florida in 1992.
The facility was designed to test the strength of the wind. In the last two years, we have seen hurricanes with winds of over 200 km/h off the coast of Mexico and in the Caribbean.
Tropical storms are getting more intense as the climate changes. For what we believe should be called Category 6 storms, new test facilities that go beyond today's capabilities will be required.
The most powerful level of Hurricane is currently the only life-size test facility in the U.S. There is a wall of wind.
There is a curved wall of giant fans at the end of the building. They can make a 160 mph storm. The water jets are in motion. Engineers can see how and where structures fail at the other end of the building.
The tempests that we create here allow us to investigate weaknesses in construction and design, track failures through a building and test innovative solutions in close to real-world storm conditions. As buildings, roofing materials and other items fall apart, cameras and sensors capture every second.
Designers and builders have been helped by ten years of research. That helps when the forecasters warn of a busy season with many hurricanes.
You can sign up for Scientific American's newsletters.
In destructive testing, a structure will rip apart in a matter of seconds. The wind must penetrate the weakest point.
Many of the less-well-constructed homes in the Bahamas were turned into projectiles. Houses built to resist higher winds are in trouble because of the flying debris. Our testing shows that debris from one building can take out the next building and then the next building can be taken out as well.
The weakest link is usually the roof. Wind hitting the surface of the building needs to be able to escape because of the force of the storm. Damage can be caused when wind runs into objects.
The new designs improve how buildings stand up. Powerful winds that swirl almost like a corkscrew at a building's edge can lift the roof. One innovation uses a horizontal wind turbine on a roof to diffuse the wind and generate power at the same time.
The shape of buildings can affect wind direction. Modern high-rises don't have sharp corners. Wind pressures can be reduced by more rounded edges.
Better safety doesn't have to cost a lot. The difference between a small, shed-size building and a Category 3 storm was shown in an experiment. The roof is attached to the house. The ring shank nails have threads around them to hold the wood in place. Entry points where the wind can penetrate and cause catastrophic failure can be blocked by hurricanes.
Installation is important and helps explain why roofs that appear to meet building code requirements can still fail.
The metal elements between the walls and the roof can fail at low winds even though the system was designed to survive a Category 5 Hurricane. The current code may not be enough to keep asphalt shingles from failing in a storm.
As the world warms, the nature of storms is changing.
Warming temperatures caused by greenhouse gas emissions help the air to hold more water and give the ocean more energy to fuel hurricanes. Bigger and more intense storms that are heavier with water and moving more slowly are going to hit the areas they hit with more wind, storm surge, flooding and debris, according to research.
One study estimated that if Hurricane Ike were to hit in the late 21st century, its winds would be 15% stronger and it would be 34% more wet.
We are working with eight other universities to design a new facility to test construction against 200 mph winds and a water basin to test the impact of storm surge up to 20 feet.
Computers can model the results, but they still have to be verified. Combining wind, storm surge, and wave action will allow us to see the entire Hurricane and how it affects people and the environment.
Disaster testing is finding ways to make homes safer but it is up to homeowners to make sure their structures are sound. Most people think of their home as their most valuable asset.
The conversation published this article. The original article is worth a read.
All Rights Reserved © 2024
