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0px; font: 12.0px Helvetica; -webkit-text-stroke: #000000; min-height: 14.0px}span.s1 {font-kerning: none}After many hours and multiple classes of reviewing and discussing which was the more efficient method for making an earthquake-resistant building, I concluded that my group and I were going to make a earthquake-resistant building by using the Tuned Mass Damper method. The Tuned Mass Damper system, which is also commonly associated with the name Harmonic Absorber, is a device mounted in structures to reduce the building’s amplitude of mechanical vibrations.
Their application can prevent discomfort, damage, or outright structural failure to a high rise building. They are also frequently used in power transmission and automobiles. Safety comes at a hefty price and standing by that statement, a tower’s tuned mass damper cost around US$4 million to build. A tuned mass damper (TMD) consists of three parts, a mass (m), a spring (k), and a damping device (c). When an outmost force is implemented, such as the an earthquake underneath a skyscraper, there has to be a quickening. As a consequence, the residents in the tower would be able to detect this acceleration.
To proceed with making the residents feel more relaxed, tuned mass dampers are installed in edifices where the horizontal diversions from the earthquakes energy are examined the exceptional establishment should match so that when the construction begins to oscillate or sway, the Tuned mass Damper starts to take effect by creating an equivalent and opposing push on the property and when the establishment is compelled right, the Tuned Mass Damper, at the same instant, forces it to the left keeping it’s horizontal dispersion at or near zero. However, if the rate of repetition was remarkably unalike, the Tuned Mass Damper would produce forces that were out of sync with the pushes from the earthquake amplitude, and the building’s to and fro would be intolerable for the residents inside, and the building would again experience too much action. The successfulness of a Tuned mass damper is reliant on the mass ratio (of the tuned mass damper to the building), the comparative number of the rate of occurrence of the tuned mass damper to the rate of the formation, and the dimming ratio of the tuned mass damper (how well the damping gadget evaporates energy).Despite not having the material to make a real-life Tuned Mass Damper, we worked with the material that we actually had in the classroom. We focused on the basic aspects of the system, such as a mass that hangs from the ceiling which is the core of this techniques and springs attaching our mass to the ceiling.
We made our mass out of 3 marbles wrapped up in aluminium and then attached 4 elastic bands around our counterweight. We then suck the elastic bands onto the top layer using hot glue. It was a necessity to not have the mass be too heavy because we decided as a group that if the mass was too large it’ll not swing and counteract the direction as well as it would’ve if the weight was not as heavy because the weight will not be equal and could potentially bring the model to a certain side instead of creating a horizontal displacement near to zero. Our elastic bands attaching the mass and the top level of our model was key to making the mass swing and creating a horizontal displacement near to zero. We made sure that our elastic band was coated in hot glue to make sure it’s secure and would not break while in a shaking motion.Taipei 101, previously named as the Taipei World Financial Centre – is a well-known high rise structure located in Taipei, Taiwan.
The judicious structure is one of the most commonly associated high rises using the Tuned Mass Damper system. The Tuned Mass Damper is a ball of stacked steel plates measuring 18 feet in diameter and weighing 728 tons, suspended above Floor 87 by cables anchored at Floor 92. This system allows for withstand typhoons and earthquakes and it’s said to cut down on the swaying of the building by almost 40%. Acting like a giant pendulum, the massive steel ball sways to counteract the building’s movement caused by strong gusts of wind. Eight steel cables form a sling to support the ball, while eight viscous dampers act like shock absorbers when the sphere shifts.
I believe that my group’s model demonstrates my chosen earthquake resistant building technique well. My group and I were able to create a model that was stable and a secure environment for our mass that we hand-made. Our model was made up of five double layers of cardboard which formed four firm levels. This made our model’s structural integrity strong and was able to withstand a powerful side to side motion from the shake table. We decided to made our counter weight from scratch because we believed that we would have more control over the adjustability and we would be certain that the weight of the damper was not too heavy for just a cardboard model. Our model, however, did not have anything that we could attach it to the shake table other than attaching tape to the bottom cardboard level, this is the main cause of damage and structural failure to our high rise cardboard model.
Our model was able to withstand six seconds of intense shaking before the tape unattached and our model fell to it’s right. After looking through our video of our model on the shake table, I concluded that our attachment on the model was done poorly. It was the root cause of the fall and our model was deeply affected by it either, which goes to show how strong our model was. All things aside, our most thought out feature of our model was that it would be strong and would not be damaged after a harsh encounter, hence why we double layered most of our materials. I believe that we were able to do this successfully and even though our model fell over, it stayed in-tact.
I also can see that our model was able to stay stable for so long because of the Tuned Mass Damper system that kept its horizontal displacement near to zero. Every time the model was thrusted in a direction the counterweight would swing in the opposite which balanced out the sudden movements. Building, power transmission and automobiles that use the Tuned Mass Damper technique seem to have shown great effect, improvement and progress from their previous state. For example, it’s been heard that Taipei 101 has cut down on the swaying of the building by almost 40%, which is amazing progress.
Once looking over all of my research and data that my group and I had gathered regarding this project, I believe that my model was a well done representation of a real-life building that used the same method. Despite not having the material to make a real-life appearing building, I do think that we were able to show how the movement of the model and the mass counteract which creates a horizontal displacement near to zero.
