I$3622$ND: Mechanical Engineering Design I

Assignment $4$

A plane stress element has ${}_x=-4$MPa,${}_y=12$

MPa $,$ and ${}_{xy}=7$MPacw, as shown in Figure Q$1.$

$($a$)$ Using Mohr's circle, find the principal stresses and

directions, and show these on a stress element correctly

aligned with respect to the xy coordinates. Draw another

stress element to show ${}_1$ and ${}_2,$ find the corresponding

normal stresses, and label the drawing completely.