The effect of SMA gage length and initial SMA stress on the dissipated seismic energy is
shown in Figure 8a. At the left end of the plot, the SMA is pushed past the full martensite
transformation strain, d f
AS , and the SMA experiences a related increased hardening, as shown in
Figures 3a and 4a. This can cause significant overstrength in the brace and may develop increased
fracture potential, so it is not recommended to use configurations to the left of the heavy solid line.
Similarly, it is not recommended to use configurations that produce normalized energy dissipation
smaller than 0.25. Based on these recommendations, a range of suggested initial SMA stress and
gage length are shown on Figure 8a. Figure 8b shows the cumulative SMA strain which
demonstrates that SMA gage lengths greater than 40% of the brace length will limit the cumulative
SMA strain to 75% which is safely below the cumulative strain capacity of 119% experienced
during the SMA component test.