I shall elaborate on how I did , hopefully it would help you in getting an understanding of
three things.
a) How a commercial finite element works (very roughly)
b) Use of Matlab for FEM
c) Better understanding of FEM itself
I solved the problem of a cantilever with a tip load with triangular as well as quadrilateral
elements.
- Beam meshed with triangular elements (CST)
For the above beam problem , apart from Meshing, I also established the
nodal connectivity of each element, calculated element stiffness and assembled it, defined loads
and bcs, and solved for displacements.
After solving , the deformed beam looked like :
2. Beam meshed with Quad elements (Q4)
I did all of the above as stated in CST , then for stiffness matrix
calculation, I used the isoparmetric formulation / jacobian and stuff .
Also, just to understand the isoparametric mapping, I gave the 8 nodes
of the quadrilateral and visualized the curved element. I then superposed the natural
coordinates (epsilon.eta=0 curves ) onto the cartesian coordinates. The below figure would give
an idea of what I did
3. Isoparametric mapping ( 8 node quadrilateral element)