5-4. A
shear force 
is applied to a square
beam with the cross section as shown. If the allowable shear stress is 
, determine the probability of failure of
the beam. Assume that 
and 
are
independent. (Ans. 
)
5-4. A
shear force is applied to a square
beam with the cross section as shown. If the allowable shear stress is , determine the probability of failure of
the beam. Assume that and are
independent. (Ans. )