by **hnxiaye** » Fri Apr 23, 2010 8:52 am

Thanks a lot fmk.

Indeed, I don't need to work on the local stiffness matrix but only global one.

Specifically for Bouc-Wen model, I guess what I need to do is like this: write down the global stiffness matrix first, then modify it by multiplying *alpha_1* (Bouc-Wen model parameter corresponding with DOF 1) to column 1, *alpha_2* to column 2 and *alpha_n* to column n. Then imaginary displacement Z (for example, z_1) would be defined according to DOF 1 related Bouc-Wen parameters. Am I right? I am not quite sure.

This is not so much related to C++, but just the theory of nonlinear model. What I originally want to do is to get a implemented scripts and figure out how they write the Equation of Motion.

Thanks again.

Ye