The rigid bar BDE is supported by two links $AB$ and $CD$ as shown in figure below. Link $AB$ is made of

aluminum $(E=70$GPa $)$ and has a cross$-$sectional area of $500m{m}^2.$ Link CD is made of steel $(E=200$CPa $)$

and has a cross$-$sectional area of $600m{m}^2.$ For the applied load F $=50kN.$

a$.$ Calculate the change of length of link CD$,{}_{CD}.$

b$.$ Determine the deflection of $E,{}_E.($positive down$).$

c$.$ If the yield strength of aluminum is $275$ MPa $,$ the yield strength of steel is $350$ MPa $,$ and the required

margin of safety of this links against yielding is $1\mathrm{.}25,$ determine the maximum load that $F$ that can be

applied to the system.

Answer:

a$.{}_{CD}(mm)=$

b$.{}_E(mm)=$

c$.F(kN)=$