PSI - Issue 64

Yunus Harmanci et al. / Procedia Structural Integrity 64 (2024) 2067–2074 Author name / Structural Integrity Procedia 00 (2019) 000–000

2071

5

Figure 2: Recorded mid-span deflections (left) and strains (right) of both beams during natural environmental exposure and sustained loading.

The four-point bending response of both beams was compared with beams from the previous study (Shahverdi, Czaderski, and Motavalli 2016), as shown in Figure 3, to assess the impact of 8 years of natural environmental exposure and sustained loading. The bending behavior of new specimens remain largely unchanged and no deterioration was observed, even despite residual displacements after sustained loading. Average ultimate loads and mid-span deflections for unexposed and exposed beams are provided in Table 2. Similar to the load vs. mid-span deflection behavior, both SMA and concrete strains eventually align with the unexposed beams. A slight increase in post-yielding stiffness can be observed for both beams, likely due to the enhanced strength and stiffness of concrete.

Figure 3: Load vs mid-span deflection (left), FeSMA strain (middle) and top concrete strain (right).

Table 2: Overview of experimental results.

Beam No.

Failure mode

F max [kN]

δ u at F max [mm]

1 2

Concrete crushing after steel yielding

9.8

48.7 70.6

Concrete crushing after steel and SMA yielding Concrete crushing after steel and SMA yielding Concrete crushing after steel and SMA yielding Concrete crushing after steel and SMA yielding

16.8

3,4,6

16.7 ± 0.26

53.3 ± 3.12

7 8

17.1 16.4

56.2 67.9