Problem $1)$ Horizantal Force $P=600N$ is applied at point E$.$ AB part is

thin$-$walled pressure vessel with an $20mm$ imer diameter and $2mm$ thickness. Interal gage pressure is $6$MPa, fo point $D,$

a$)$ find stress matrix,

b$)$ Show stress state on infinitesmall cube,

c$)$ Find principal stresses by using MOHR'S CIRCLE

d$)$ Show principal stresses on the rotated infinitesmall element