Computing D-Matrix - Code Answer

Question 1

What are the SIX LINES under ‘dmatx(1:3, 1:3) = 0;’?

Answer 1

const = young / (1.0 - poiss*poiss);
dmatx(1, 1) = const;
dmatx(2, 2) = const;
dmatx(1, 2) = const*poiss;
dmatx(2, 1) = const*poiss;
dmatx(3, 3) = (1.0 - poiss) * const / 2.0;