Evaluate stress induced in rod:

The two copper rods and one steel rod lie in vertical plane and support load of 50kN together as shown in figure given below. Each rod is 25 mm in diameter, the length of steel rod is 3 m and the length of each copper rod is 2m. If modulus of elasticity of steel is double that of copper, make calculations for stress induced in each rod. It can be presumed that each rod deforms by same amount.
Sol.: Each rod deforms by same amount and accordingly that is,

 
 
Division of load between steel and copper rods is given below:
total load = load carried by steel rod + rod carried by two copper rods

  σC  = (50 × 103)/1633.78 = 30.60 N/mm²     .......ANS
σS  = 1.33   C  =1.33 × 30.60 = 40.7 N/mm²