If you see this equation, what is your first impression??
It is look like very simple equation. But if I expand that equation, the equation will be looked like something like this:
The equation become very long and complicated....I take more than one month try to solve it, but I still can't finished yet...
Mathematic oh mathematic.....
on Tuesday, October 13, 2009What is HDRB?
on Tuesday, July 7, 2009High Damping Rubber Bearing (HDRB) have been practically applied in structures for more than 20 years. The excellent isolation effect and reliability have been globally verified and examined by several actual cases. Therefore, they have been widely used in bridges, buildings, factories and many kinds of structures and provided structures excellent protection against the damages of earthquake.
Characteristics：
# Reduce the seismic loading transiting into structures (Isolation).
# Dissipate the vibration energy and decrease displacement into structures (Dissipation)
# Uniformly distribute the loads to main supports of structures.
# Decrease the stresses in structure caused by creep, shrinkage and thermal expansion/contraction.
# It is capable of all the functions of normal bearings
# Reduce the construction cost
# Enable the bridge being designed as multiple continuous spans and minimum the numbers of joints.
# Maintenance free and the longevity are longer than 60 years.
Combination of isolators system:
# The period Shift Effect: reduce the horizontal stiffness of structure and shift the period of structure to be a longer period.
# Energy Dissipation: the damping characteristic decrease both acceleration and displacement.
The most popular isolator systems are the elastomeric pad combined with damper or viscous materials, or sliding damping. Lead Rubber Bearings are the combination of elastomeric pad and damper. High Damping Rubber Bearings are the combination of elastomeric pad and viscous materials.
Structures without Isolators VS. Structures with Isolators
When the earthquake occurs, the structures without isolators will move severely together with ground acceleration and the structures with isolators will parallel move slowly.
Building without isolators VS Building with isolators
Multiple continuous span bridge VS Bridge with isolators
Functions of Seismically Isolated Bearing Components
High Damping Rubber Bearings are manufactured in the way as laminated elastomeric bearings, except that a special formula of rubber are used to obtain a higher damping characteristic to dissipate the energy and decrease the displacement during the horizontal deformation.
Behavior of HDRB in the shaking table test
Finally, my professor gives me an explanation about my master thesis. My research will focusing on base isolation system using high damping rubber bearing (HDRB). This is some explanation about my master thesis.
The complex hysteresis behavior of one of seismic isolation bearings, the High Damping Rubber Bearing (HDRB), has introduced difficulties in the establishment of analytical model. Some complicated analytical models established using visco-elasticity and visco-plasticity can only approximate the hysteresis behavior of HDRB to some extend. Consequently, it is very difficult to perform the time history analysis and to obtain accurate seismic responses of a building structure isolated by high damping rubber bearings. Recently, a mathematical model has been published by my professor, in the Earthquake Engineering and Structural Dynamics which can well capture the hysteresis behavior of HDRB. Adopting this model and utilizing the results from a series of shaking table test of isolated model structures as can be seen in Figure, the research topics involved in my master thesis include:
The complex hysteresis behavior of one of seismic isolation bearings, the High Damping Rubber Bearing (HDRB), has introduced difficulties in the establishment of analytical model. Some complicated analytical models established using visco-elasticity and visco-plasticity can only approximate the hysteresis behavior of HDRB to some extend. Consequently, it is very difficult to perform the time history analysis and to obtain accurate seismic responses of a building structure isolated by high damping rubber bearings. Recently, a mathematical model has been published by my professor, in the Earthquake Engineering and Structural Dynamics which can well capture the hysteresis behavior of HDRB. Adopting this model and utilizing the results from a series of shaking table test of isolated model structures as can be seen in Figure, the research topics involved in my master thesis include:
1. To perform cyclic loading test of HDRB isolation bearings
2. To identify the parameters in the mathematical model
3. To develop a computer program implemented with the mathematical model of HDRB, which is2. To identify the parameters in the mathematical model
capable of performing the seismic analysis of seismically isolated structures
4. The result from the shaking table test will be analytically correlated with the being developed computer program
5. The study will be further extended to the mid-story isolated structures which have become one of the major construction methods for the isolated structures located in the highly populated areas where building separation is of major concern
4. The result from the shaking table test will be analytically correlated with the being developed computer program
5. The study will be further extended to the mid-story isolated structures which have become one of the major construction methods for the isolated structures located in the highly populated areas where building separation is of major concern
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