Civil Engineering Reference
In-Depth Information
Figure 6.4
Loading procedure
proportional loading was simulated by small, step-wise increments so that the Hsu/Zhu ratios,
ν
12
and
ν
21
, could be measured at each load step. A load-control procedure was used to apply
the external stresses
σ
2
before the steel yielded, while a strain-control procedure was
used after the yielding of steel.
σ
1
and
Load-control procedure before yielding
Figure 6.4(a) shows a step-wise proportional loading using load-control procedure before
yielding. When the compressive stress
σ
2
was increased and the tensile stress
σ
1
was main-
tained constant, the source strain increment
ε
2
and the resulting strain increment
ε
1
were
measured at this loading step. The Hsu/Zhu ratio
ν
12
is then calculated from the measured
strain increments as
ε
1
ε
2
ν
12
=−
(6.27)
