60. A torsion bar AB fixed at A is simply
supported at B and is connected to a cantilever BC as shown in
the figure. A force 
is applied at C. Bar AB
has a spring rate of 
and a length of 
. Cantilever AB has a spring
rate of 
. If the allowable deflection at C
is 
and the maximum probability of
failure is designed to be 
, determine the maximum length of
BC using First Order Second Moment Method. Assume that 
,
and 
are independent.
Answer: 
