How did NASA find anti-earthquake technology for buildings?

Normally, NASA technology engineers will focus on improving human safety when exploring the universe.

But now the space agency says they have found a way to make earthquakes safer for people on the ground.

NASA developed a new stabilization technology, called LOX Damper , in 2013 after working with a rocker that shook violently. After testing, they found that the Ares missile, a crew launcher, would shake very strongly when levitated and could damage astronauts on board. So a NASA research team experimented with controlling the heaviest part of the rocket - fuel. And it makes them think: If this technology works with rockets, why not try building on buildings?

To understand what is special about this new technology, you should know that the usual approach to preventing vibration is by adding mass to an object. Hundreds of buildings around the world are using a system called volume damper (TMD) . An extremely heavy device, called the second heavyweight , is attached to a building to resist its movement. One of the tallest skyscrapers in the world, Taipei 101 in Taiwan, has a 730-ton steel ball fixed by steel cables.

Comcast Center in Philadelphia, has a water tank with a gallon capacity. These systems respond to movement by moving in the opposite direction. So when an earthquake or strong wind causes the building to rotate to the right, the TMD system will react by turning to the left - minimizing movement.

Steel ball 730 tons of Taipei 101, Taiwan.

But TMD also has limitations. First, they are extremely expensive. (Retrofitting the Theme Building at Los Angeles International Airport, it requires 600 tons of steel and costs about 12.3 million USD.) And TMD is also very large, making buildings use them "lost important real estate , " said Rob Berry, NASA project manager for the technology development team.

In the case of the Ares rocket weighing 300 tons, a TMD system is impractical. Increasing the volume can make taking off into utopia. Berry and his team must be creative. They realized that making rocket fuel moving in the opposite direction to vibration would perform the same functions as adding more mass. So they determined the frequency of the rocket's vibration - and changed the frequency of the liquid to match it.

The final version of LOX Damper weighs less than 45kg and is installed in the rocket's main fuel chamber. This changed the rock's basic reaction, resulting in up to 20 times less vibration. And so we have a safe rocket with people.

And the same way can be applied to buildings, Berry explained.

"Everything with volume and hardness has a natural frequency, (so) a building will always want to move," he said.

"For example, a building wants to move at 2.5 herzt. They will set that frequency for the volume damper system. And that will cancel some of the building's reaction."

But the external forces that made the building shake could not be applied to these calculations - all at the frequency of the building's movement. To test new technology, NASA's development team created a new device called Disturbance Mass Control (DTM) , designed specifically for buildings. After an experiment at the Marshall Aerospace Center in Alabama, and proved successful, NASA "went to engineering and design companies" to tell them about their new opportunity, according to Berry.

The latest version of this device is only equivalent to the size of a can of coffee. It can be placed in the building's swimming pool, plumbing, or even a watering system. After engineers determine the frequency at which the building will move in events such as earthquakes or strong winds, the DTM device will be set to match that frequency. This will be like attaching a heavy piece to the building and fighting it effectively, like tying bricks to a dog's tail.

The goal of B2 engineers is to minimize the movement of the building when there is strong wind.

Existing buildings can be retrofitted with these devices, and the system can also include a new design. The B2 building at Pacific Park, Brooklyn, New York, will be the first commercial property to be installed with DTM. This decision came from after Thornton Tomasetti had visited Marshall to observe the experimental building.

"Thornton Tomasetti has seen its simplicity and efficiency and they decided to incorporate it into their B2 building," Berry said.

The goal of B2 engineers is to minimize the movement of the building when there is strong wind. But if the building owner decides that they want the structure to be more stable and resistant to earthquakes, they can install DTM to adjust the frequency.

Installing NASA technology also means that the building can resist the movement from an unexpected earthquake. With the traditional TMD system, the building will have to endure all external forces for about four to five seconds so that the second heavy bureau can start moving. Those few short seconds can bring destruction.

Although there is no way to completely stop earthquakes. But it is clear that we can do more to protect buildings from the displacement of tectonic plates under the Earth's crust. Thanks to NASA, engineers now have another option.