Question $5$ : Shear Stress $-$ Shear Flow

Three identical boards are bolted together to form a built$-$up beam, as shown

in Figure $5$ below. If the wood has an allowable shear stress of

${}_{\text{a}\text{l}\text{l}\text{o}\text{w}}=3$MPa, determine : $-$

the maximum allowable internal shear force $V$ that can act on the beam.

$[$Hint: find $V_{\text{m}\text{a}\text{x}}$; which may not necessarily be at the $NA]$

a$)$ Also find the corresponding average shear stress in the $9mm$ diameter

bolts which are spaced equally at $s=150mm.$

Figure $5$: Built$-$up Beam