Seismosoft | Earthquake Engineering Solutions

I have to calibrate SIMPLIFIED BILINEAR TAKEDA CURVE for hysteretic response of bridge pier. I need the following parameters to calibrate the hysteretic curve.
1. Yield strength, Fy
2. Initial Stiffness, ky
3. Post-Yielding to Initial stiffness ratio, (alpha)
4. Outer Loop Stiffness Degradation Factor (beta o)
5. Inner Loop Stiffness Degradation Factor (beta 1)

Please share your views and/or relevant papers.

Pages 314 and 315 of the SeismoStruct User's Manual should get you started on these parameters, adeelfaisal.