proportional damping

huangyhg

proportional damping
it is mentioned in a japanese book titled seismic design methods, (limit state design method) that:
modal analysi for time-history method will be used when the damping matrix in differential equation of motion is a proportional damping.
what is the meaning of proportional damping?
also will be glad if you can introduce a site to get more detailed data on this issue.
tia
rasoul khoshravan
civil engineer
osaka, japan

try this
a quick yahoo search for "idarc" turned up ...
aquestion from hydraulic engineering
what is the appropriate english word to describe:
amount of water in time unit
its unit is: m3/second
yabi
flow rate in cubic meters per second, however in us the preferred unit would be cubic feet per second.  this would probably apply to flow in rivers, channels or storm drains
dear cvg
thanks. i know this phrase but this is not a word. in my language there is only one word expressing this phrase, named: debi, might have forigen origin.
isn't there a single word to express it in english?
use these,
"flow rate"
       sometimes
"flowrate"
       sometimes
"rate of flow"
flow rates can be expressed volumetrically or by mass
volumetric flow rate => cubic feet / second (cfs)
mass flow rate => pounds(mass)/hour         (lbm/h)
sometimes lbs/h, lbs/s, etc. with mass implied
common english units are many, most common are,
volumetric flow rates,
barrels/day oil (bopd) = barrels of oil per day"
barrels/day other = bpd
cubic feet/second (cfs)
us_gallons/minute (gpm)
us_gallons/hour (gph)
mass flow rates,
pounds/second lbs/s
pounds/minute lbs/m
pounds/hr     lbs/h
tons/year     ton/yr
   going the big inch!