Equivalent dumping coefficient
Encyclopedia
An equivalent dumping coefficient is a mathematical
coefficient
used in the calculation of the energy dispersed when a structure moves. As a civil engineering term, it defines the percent of a cycle of oscillation that is absorbed (converted to heat by friction) for the structure or sub-structure under analysis. Usually it is assumed that the equivalent dumping coefficient is linear
, which is to say invariant compare to oscillatory amplitude. Modern seismic studies have shown this not to be a satisfactory assumption for larger civic structures, and have developed sophisticated amplitude and frequency based functions for equivalent dumping coefficient.
When a building
moves, the materials it is made from absorb a fraction of the kinetic energy
(this is especially true of concrete
) due primarily to friction
and to viscous or elastomeric resistance which convert motion
or kinetic energy to heat
.
Mathematics
Mathematics is the study of quantity, space, structure, and change. Mathematicians seek out patterns and formulate new conjectures. Mathematicians resolve the truth or falsity of conjectures by mathematical proofs, which are arguments sufficient to convince other mathematicians of their validity...
coefficient
Coefficient
In mathematics, a coefficient is a multiplicative factor in some term of an expression ; it is usually a number, but in any case does not involve any variables of the expression...
used in the calculation of the energy dispersed when a structure moves. As a civil engineering term, it defines the percent of a cycle of oscillation that is absorbed (converted to heat by friction) for the structure or sub-structure under analysis. Usually it is assumed that the equivalent dumping coefficient is linear
Linear
In mathematics, a linear map or function f is a function which satisfies the following two properties:* Additivity : f = f + f...
, which is to say invariant compare to oscillatory amplitude. Modern seismic studies have shown this not to be a satisfactory assumption for larger civic structures, and have developed sophisticated amplitude and frequency based functions for equivalent dumping coefficient.
When a building
Building
In architecture, construction, engineering, real estate development and technology the word building may refer to one of the following:...
moves, the materials it is made from absorb a fraction of the kinetic energy
Kinetic energy
The kinetic energy of an object is the energy which it possesses due to its motion.It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes...
(this is especially true of concrete
Concrete
Concrete is a composite construction material, composed of cement and other cementitious materials such as fly ash and slag cement, aggregate , water and chemical admixtures.The word concrete comes from the Latin word...
) due primarily to friction
Friction
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and/or material elements sliding against each other. There are several types of friction:...
and to viscous or elastomeric resistance which convert motion
Motion (physics)
In physics, motion is a change in position of an object with respect to time. Change in action is the result of an unbalanced force. Motion is typically described in terms of velocity, acceleration, displacement and time . An object's velocity cannot change unless it is acted upon by a force, as...
or kinetic energy to heat
Heat
In physics and thermodynamics, heat is energy transferred from one body, region, or thermodynamic system to another due to thermal contact or thermal radiation when the systems are at different temperatures. It is often described as one of the fundamental processes of energy transfer between...
.