15 mm dia SS (Young’s modulus = 200 Gpa) rod is coated with HA (Young’s modulus = 300 Gpa). What should be the coating thickness (in mm) so that the Young’s modulus of the composite is 209 Gpa (use mixture rule)?
We know that, for the composite material
Where, Y1, Y2 are the young modulus for composite material; and
V1 and V2 are the volume
Since, height will be same and only their cross sectional area is changing