PSI - Issue 64

E. Choi et al. / Procedia Structural Integrity 64 (2024) 2028–2035 Eunsoo Choi / Structural Integrity Procedia 00 (2019) 000 – 000

2032

5

Pushing

Pulling

LVDT locations

Rear

Front

Heating jacket

(a) Test setup

(b) External heating jacket

Figure 5. Test setup and instrumentation

4. Test results The hysteretic force-displacement curves of the specimens are shown in Figures 6(a) – (c), where the displacements were from a height of 1400 mm, and the corresponding envelopes are shown in Figure 6(d). From the curves, specific values such as the peak force, yield and failure drift ratio, and displacement ductility factor were estimated (Table 1). The displacement ductility factor is defined by = / , where and are the yield and ultimate displacements, respectively. The RC-ref specimen exhibited the typical behavior of RC columns, and thus, its yield point was defined as the intersection of a line passing from the origin to the point of 0.75 peak force and a horizontal line passing through the failure point of 0.85 peak force during softening.

Drift ratio (%)

Drift ratio (%)

−6

−4

−2

0

2

4

6

−8 −6 −4 −2

0 2 4 6 8

150

(a) RC-ref

(b) RC-SMA-N

100

100

50

50

0

0

−50 Load (kN)

−50 Load (kN)

−100

−100

−150

−80 −60 −40 −20

0 20 40 60 80

−100

−50

0

50

100

Displacement (mm)

Displacement (mm)

(d) Envelops −7 −6 −5 −4 −3 −2 −1 0 1 2 3 4 5 6 7 Drift ratio (%)

Drift ratio (%)

(c) RC-SMA-H −8 −6 −4 −2

0 2 4 6 8

150

100

100

50

50

0

0

−50 Force (kN)

Load (kN)

−50

RC-Ref RC-SMA-N RC-SMA-H

−100

−100

−120−100 −80 −60 −40 −20 0 20 40 60 80 100 120 −150

−100

−50

0

50

100

Displacement (mm)

Displacement (mm)

Figure 6. Hysteretic curves and the envelopes of the specimens