$1-83.$ Determine the required minimum thickness $t$ of

member $AB$ and edge distance $b$ of the frame if $P=40kN$

and the factor of safety against failure is $2.$ The wood has a

normal failure stress of ${}_{\text{f}\text{a}\text{i}\text{l}}=42$MPa, and shear failure

stress of ${}_{\text{f}\text{a}\text{i}\text{l}}=10\mathrm{.}5$MPa.

I know how to solve this problem, but there's been a question bothering me$.$ I've calculated Bx to be $34\mathrm{.}6$ kN$,$ which will cause shear stress on the upper surface $($marked in blue$).$ But since the force Bx is also parallel to the side surface $($marked in black$),$ will it also cause shear stress there? Why can't we use the black$-$marked surface to calculate the length b$?$ Thanks $1-83.$ Determine the required minimum thickness $t$ of

member $AB$ and edge distance $b$ of the frame if $P=40kN$

and the factor of safety against failure is $2.$ The wood has a

normal failure stress of ${}_{\text{f}\text{a}\text{i}\text{l}}=42$MPa, and shear failure

stress of ${}_{\text{f}\text{a}\text{i}\text{l}}=10\mathrm{.}5$MPa.

Prob. $1-831-83.$ Determine the required minimum thickness $t$ of

member $AB$ and edge distance $b$ of the frame if $P=40kN$

and the factor of safety against failure is $2.$ The wood has a

normal failure stress of ${}_{\text{f}\text{a}\text{i}\text{l}}=42$MPa, and shear failure

stress of ${}_{\text{f}\text{a}\text{i}\text{l}}=10\mathrm{.}5$MPa.

Prob. $1-83$