use the solver inside one element

[burnningcat]

Dear Sir,

I need to perform an analysis inside one element. That means I need to assemble the stiffness of three sub-elements and use the solver to solve the nodal displacements inside one element. But would you please teach me how to do this in the code?

Which command is to: 1. assemble the stiffness matrix 2. Apply the boundary conditions (including the constrain equations) 3. Call the solver to do the iterations and solve the nodal equations… (I mean the c++ command to use the existing ability in OpenSees.)

I am a student and I really need your professional guide, thank you very much.

[sanat]

Your question is kind of fundamental question behind opensees solver. i recommend you to refer to fmk's phd dissertation.

[burnningcat]

Dear Sanat,

Really thank you for you reply!! Because I need to solve a sub-structural in my work, and OpenSees has so powerful capability then it seems not so wise to do this stuffs again by myself. It seems quite nice if I can use the existing tools in OpenSees.




I am reading the code, and I am trying to build another model and domain and add one node into it:

static Domain *theTclDomain1 =0;
Node *theNode1 = 0;
theNode1 = new Node(5,2,10.0,10.0);
theTclDomain1->addNode(theNode1) ;


It has no problem at all when you compile and build the OpenSee.exe, but when you run an error happen( *** memory can not be read) and the program stops. I think this is because I am not so clear about the realationship of the classes in OpenSees and the program can not assign the memory correctly.


I think I miss some lines in my code, would you please teach me how to fix it ? Thank you very much!

[fmk]

your domain is a NULL pointer! .. if you don't understand this you need to learn some C++ before you start using the OpenSees framework.