Question from one of my exams,I am lgoing crazy becaue this is against everything I understand. Please please please help me : http://imageshack.us/f/189/examh.jpg/ Basicaly,I need to found what the "0" degree shows me on elongation. As I look at the hole in the figure,I see the pressure everywhere is perpendicular to its surfice. That means,the stress is perpendicular to the surfice,and there is no stress in direction of "a". All the stress goes in direction of "b". In my logic,that meansthis is case of simple Hook Law with use of Poisson ratio.Because the stress in the direction of b,then elongation there must be bigger. But it is not the case.Why why why oh god why!!?? Thanks in advance.