The second-highest building in the worlditem at the very topThe Shanghai Tower is an imposing highlight in the skyline of the Chinese metropolis. Its architectural design is a fusion of elegance and functionality. A tuned mass damper plays a key part in keeping the building stable – and is based on a frame structure from item.
Shanghai is the most important economic metropolis in China.The industrial city is home to the world’s biggest shipping port, as well as countless chemical companies, dockyards, textile producers and car manufacturers.
The Shanghai TowerStanding at a height of 632 m, the Shanghai Tower is the tallest structure in China and the second-tallest in the world. It has more than 128 floors and a total floor area of 380,000 m2.
A mega-buildingThe Shanghai Tower is divided into 9 zones, each comprising up to 15 floors. The three elevators are the fastest in the world and travel at a speed of 18 metres per second (40 miles per hour).
Ready for the challengeLocated near the coast, the Shanghai Tower has to withstand powerful storms. High winds and earthquakes can also cause vibration in the tower. However, the building uses an innovative technology to keep any such movement to a minimum. And that is where item comes into play.
A heavyweight takes on nature’s furyBesides its special architectural design, the Shanghai Tower has another tool to help it withstand tough conditions. Between the 125th and 126th floor is a 1000 metric ton tuned mass damper weight suspended by 12 steel cables.
The Eddy current damperAt the lower end of the model, you can see the weight, which is connected to the steel cables. There is also space for a sculpture, titled “Shanghai Insight”.
Magnetism vs. vibration Underneath the weight are plates of pure copper that are fastened to the reinforced concrete floor using item profiles. Huge permanent magnets induce Eddy currents in the copper plates, thereby generating a magnetic field that works in the opposite direction to the weight to generate a contactless braking effect. As a result, the Shanghai Tower is largely resistant to external vibrations.
item as a sound foundationThe copper plates are bolted to frames built from torsion-resistant item profiles (80x80). These aluminum profiles ensures that the copper plates can withstand an opposite force which is generated inside of the copper plates during the movement of the magnet that stay on the top of the relative copper plates, that force could lift a 300 metric ton aircraft.
A closer lookThe individual elements of the Eddy current damper
Tested in intricate detailDetailed testing was carried out in advance to ensure the mass damper would be fully effective. Besides carrying out 3D computer simulations, engineers also built a complete replica system on a smaller scale.
1000 metric ton weightAnd so the model became a reality. Thanks to the enormous weight, the Shanghai Tower can withstand even the strongest winds and vibrations.
Division of Vibration Control System, Shanghai Research Institute of MaterialsQian FengChief Engineer
“This is one of the tests we carried out on
the Eddy current tuned mass damper. Our construction team used a hydraulic cylinder to move the weight to a large distance then let it go. The magnets and the copper
help to guide the energy to the building. You can see the item profiles
underneath the copper plates.”
Why aluminium?All the profiles were first lifted up to the 132nd floor by a tower crane and then carried by workers down to the 125th floor. Had they been made of steel, it would have taken more than three times the number of workers to move them. What’s more, the material is extremely strong, in fact, just as strong as stainless steel and cheaper at the same time.
Why aluminium?The force of attraction from the strong permanent magnets would act directly on steel or iron girders, thereby weakening the damper. Aluminium is paramagnetic and much more resistant to strong magnetic fields. The high-strength item profiles provide a holding force that is equal to that of steel girders, but are cheaper. Furthermore, the construction makes it easier to replace plates.
Division of Vibration Control System, Shanghai Research Institute of MaterialsQian Feng on itemChief Engineer
“We also tried out Chinese and Japanese
profiles. However, item exhibited the best quality in our comparative tests.
After getting in touch with item, I particularly appreciated their high quality standards and just how easy it is to integrate the CAD models that we were able to generate directly using item software.
We were also very happy with their communication and customer service.”
item Industrietechnik GmbH
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Telephone: +49 / 212 / 65 80 -300
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