The Origin-Oriented bilinear model exhibits a distinct stiffness degradation and self-centering behavior. Upon reaching a new maximum displacement in any direction, the stiffness is degraded to a line joining the new peak to the origin. This degraded stiffness governs the behavior in both directions as shown in Figure 29. While not entirely realistic, this model has been used to model shear walls and systems exhibiting significant stiffness degradation, and for some re-centering systems. A number of researchers have used similar models over the years. See Murakami and Penzien for an example.

References:

1. Murakami M., Penzien J., "Nonlinear response spectra for probabilistic seismic design and damage assessment of reinforced concrete structures",  Report No. UCB/EERC-75/38, Earthquake Engineering Research Center, University of California, Berkeley, 1975-11, 99 pages.

Figure 29: Hysteresis Behavior for the Bilinear Origin-Oriented Model