Problem $4(35$ points$)$

Determine the residual stresses at the critical locations of an open hole in a plate that is subjected to $20$ ksi stress. The hole is $1$ inch round and it is centered in a $4$ inch wide plate. The plate material is $2024-$T$42.$ Use the stress$-$strain curve from MMPDS$.$ What happens if the material of the plate was made from $7075-$T$6?$ Document all your assumptions.

Figure $3\mathrm{.}2\mathrm{.}3\mathrm{.}1\mathrm{.}6($a$).$ Typical tensile and compressive stress$-$strain and compressive tangent$-$modulus curves for $2024-$T$3$ aluminum alloy sheet at room temperature.

Figure $3\mathrm{.}7\mathrm{.}6\mathrm{.}1\mathrm{.}6($a$).$ Typical tensile and compressive stress$-$strain and compressive tangent$-$modulus curves for clad $7075-$T$6$ aluminum alloy sheet at room temperature.