Node plastic rotary damper hysteretic damper is installed on the beam and the support, in the normal state of the energy dissipation system does not play a role,only in the earthquake, damper through plastic deformation to consume theearthquake energy. However, under the current design of the building, can meet the requirements in seismic design, does not need the damper in general; large earthquake or accidental over fortification intensity earthquake (earthquakeforecast hard) under the action of dampers, need to reduce the seismic response of structure. Thus, the hysteretic dampers using steel plate out of planedeformation energy dissipation can hardly meet the requirements. In order tomaximize the role of energy dissipation system, damper should have two characteristics good deformation energy dissipation with large initial stiffness andyield.
Damper use is not always Everything is going smoothly., international too much has happened since the damper oil spills, leading to failure, rework accident
In fact, damper and unlike some people think is not essential products. The design of the damper once failure, not only the original is not up to the bad effect, alsomay produce unexpected. Such as:
Change the stiffness change cycle, structure, seismic force increases, cause damage;
Not even damage caused by additional force, torsion;
Deformation due to increasing wear failure of expansion joints;
Bearing damper failure caused the destruction of bridge.
Silicone oil and silicone material, as a chemical raw material damper with silicone oiland silicone two materials, can be bought in the USA Du Bang company easily, apink clay like substance, a colorless transparent viscous liquid.
The beginning of the 50′s, Taylor was the first to silica gel for vibration dampingdevice. As a one-time shock no buffer requirements of high parameter, still use the material as filler.
In 60, Taylor found that the material temperature damper steady performance is poor, can not achieve the high precision liquid spring and damper requirements.With the study of silicone oil and sealing materials and measures of success, the Tyler Company in the liquid spring and damper successful use liquid silicone oil.That is to say, it was more than forty years ago, it has been American and other advanced production plant products eliminated. This backward forty years oftechnology and material, why are so many manufacturers still apply? As mentioned before, estimation is mainly they solve the sealing problem not under high pressure.
Reportedly, some manufacturers, is to achieve this yield device is filled with silica gel material ”putty”, the silica gel is not suitable for locking device for long-term use,the reason is:
Changes in temperature of silica gel is very large, when the cold (-10 ℃), silica gelinto a solid hard, loss of activity, not viscous effect. When heated (such as 30 DEG C), silica gel will become very thin, very mobile, viscous properties will be lost.
Poor thermal conductivity, the silica gel, thermal conductivity is poor, when a part ofheat, the temperature will rise quickly, but other places have changed little, to make the device in the solid-liquid heterogeneous. Because the clay is composed ofrubber powder and silicon liquid, the local heat will make the silica gel into the two parts of the original liquid, resulting in the physical properties of inhomogeneous.Advice
Long term use of poor performance, in the 1-2 stress cycle the initial use, silica gel as the locking device of filling materials, look can also work. But several cyclespast, filling material heating, will produce silica modification and material separation phenomenon, the hysteretic curve is rapid change. The damper is out of control.
Using the silica gel material, initially to produce no oil leakage problem, after a period of use, in the cold environment of oil solid separation, it will produce the same oil. For the above reasons clay for locking device of filling materials, has never been subjected to long-term load, tens of thousands of times of reciprocatingtest report. It cannot meet the practical testing requirements. In American already belongs to be eliminated products