MacRae (7) and Ji (8) revealed that continuous columns in concentrically braced frames can reduce story drift
The hysteresis loops (load versus story drift
) of four test specimens are presented in Figure 8.
. Table 5 lists the maximum story drifts
at each position of foundation.
Results of the analyses in terms of story drift
, base shear, and status of plastic hinges developed in the structure are summarized in Table 1.
For 10-story structures, the maximum story drift
decreases by 10.5% and the maximum acceleration decreases by 12.1% when [V.sub.s] = 200 m/s after optimization; with the increase of soil stiffness, the decreasing degree increases gradually; for fixed base condition, the decreasing degrees of maximum drift and acceleration are 21.6% and 18.2%, respectively.
According to the "code for seismic design of buildings" (GB50011-2010), the limits on story drift
of steel structure under frequent and rare earthquakes are taken as 1/250 and 1/50, respectively.
LVDT1 measured the story drift
that is the basis for further analysis of the panel performance.
It is regarded that a structure may collapse when the story drift
angle exceeds the criterion of 1/50 .
Figure 3 shows the final configuration of shear walls, which satisfies the lateral displacement and inter- story drift
limits for the x-direction wind.
The story drift
of this test cantilever beam before damage is used as datum line to compare the damaged story drift
of test cantilever beam.
Equation  has been proposed to predict the shear strength ratio at capacity, although this equation was derived from data obtained at a shear deformation angle of 1/100 radian or 24-mm story drift
for a 2.4-m-tall wall.
Maximum story drift
ratio (ISDA) is used in this paper as an index of structural damage addressing the proposition of FEMA 356 , and FEMA 356 defined three different performance limits to describe the damage level of structures.