How to solve

PROBLEM $2(8$ Points$/25)$

For the $3-$D stress state shown on the ductile element below, find the limiting values of ${}_z($tension and compression$)$ that would cause initial yielding in the material with a factor of safety of $($FS$).$ The yield strength of the material is $S_y$MPa. Use Tresca criterion.

GROUP $2$: Consider: $S_y=750$MPa;$FS=2\mathrm{.}8$;${}_x=-30$MPa;${}_y=50$MPa

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