Element stiffness matrix for 4 noded quadrilateral - Code Answer

Question 1

What does the ‘for in = 1 : nnode;’ loop consist of?

Answer 1

elcod(in, 1 : ndime) = coord(lnods(ielem, in), 1 : ndime);

Question 2

What line (2 statements) comes under ‘%Set local coordinates xi and eta at the current gauss point position’?

Answer 2

xi = posgp(igaus, 1); eta = posgp(igaus, 2);

Question 3

What line comes under ‘[jac, jaci, detJ, cartd] = jacob(ndime, nnode, elcod, xi, eta, shape, deriv);’?

Answer 3

dvolu = detJ * weigp(igaus) * thick;

Question 4

What THREE LINES come under ‘%Form DB matrix and element stiffness matrix’?

Answer 4

dbmat = dmatx * bmatx; 
bdbmt = bmatx * dbmat;
estif = estif + bdbmt * dvolu;