A thin plate with a circular hole is given in Fig. Q$1.$ The plate is part of a large structure that will be

subjected to cyclic tension$-$tension load. The loading cycle is given as $P(t)=20-cos(t)$ in $kN.$ If

the loading amplitude $=10kN,$ height $H=500mm,$ width $w=200mm,$ and radius $r=10mm.$

a$)$ Calculate the stress amplitude, the stress range, and also the mean stress at material points $B$

and $B^{**}$ by assuming a stress concentration factor $K_t=1\mathrm{.}0.$

b$)$ Calculate the stress amplitude, the stress range, and also the mean stress at material points $A$

and $A^{**}$ by assuming a stress concentration factor $K_t=3\mathrm{.}0.$