A wood beam $(E=17$GPa,${}_{\text{a}\text{l}\text{l}\text{,}\text{w}\text{o}\text{o}\text{d}}=14$MPa$)$ is reinforced with attaching

steel plates $(E=190$GPa,${}_{\text{a}\text{l}\text{l}\text{,}\text{S}\text{t}\text{e}\text{e}\text{l}}=140$MPa$)$ on top and bottom of beam.

$h_w=180(mm),t_s=7(mm),w=100(mm)$

Determine the maximum allowable bending moment with reference to the

allowable stress in the wood beam.

$20\mathrm{.}22kN.m$

$38\mathrm{.}62kN.m$

$28\mathrm{.}85kN.m$

$48\mathrm{.}15kN.m$

$50\mathrm{.}92$ kN$.$m