I have installed Optim1.6.1 package. I would like to solve a system of equations in non linear finite element analysis using constraints as u=1 at certain nodes. u=0 at certain nodes. Typically I find kmat and res as below
The optimisation syntax in octave is as follows
[x, obj, info, iter, nf, lambda]=sqp(x0, @g, @h, upperbound, lowerbound, iter, tol)
- Here, 'g' seems to be the objective function which is given as a function of variables and equations. Similarly 'h' is considered the system of equations in symbolised form such as x1, x2 etc. I see several examples in this template. I'm not clear on how to input the stiffness matrix, residual matrix, since the matrices are computed in a separate script as a function of several variables.
- In general what is the objective function in a non linear FEA problem with mechanical loading? It the energy residual? Can I find a simple example of a simple mesh?
I feel quite stuck with this problem for quite a long time. If these are too basic please suggest me some reading material.