The figure shows a fabric$-$testing machine. For the surface element at $A$ on the top face of the bracket bar, you are requested to determine the values of the principal stresses $({}_1$ and ${}_2),$ the vonMises stress and the Tresca stress. The bracket bar is fixed to the rigid support. The diameter of the bracket bar is $20$ mm $.$ The applied $400$ N load is divided equally between the two bracket bars.

$\backslash$table$[[$Bending stress: $=\frac{MC}{\text{I}}$;$C=$ radius and $I=\frac{}{64}{d}^4,$Torsional Shear Stress: $=\frac{TC}{J}$;$J=\frac{}{32}{d}^4$