To record the stiff matrix of a 3D structure

[gaohouzhi]

hi, I construct a three model 10 story structure . I want to get the whole sturcture stiff matrix at the first step of seism analysis, and the stiff matrix at the last step .

Through comapring the two stiff matrixs,I can get the Information of the damage state of the whole structure suffering a large earthquake.

How should I do?
Could you give me some direcitons,fmk ,or other experts.
Need your help eagerly.

[gaohouzhi]

could you give me your experience in this field?
And what do you think about this problem?

[gaohouzhi]

beg your replies eagerly.

could you help me,any suggestions will be very important for me

need your help eagerly

[fmk]

modify one of the system of equation objects to spit the matrix out. i suggest you choose a simple one like banded general.

[gaohouzhi]

I was greatly surprised by your replies .It enlighten me greatly .

But ,there are some difficulties:I hasnt make any effort to read the C++ source codes. and so without any instructions to the source codes of equation object ,I will pour too much time to understand the property of the equation object .

So I suggest you develop this function of recorder stiffness matrix in OPNESEES sincerely.

with this function embeded in OpenSees, engineers and researchers all around the world will be greatly benefited.