A copper rod 30mm diameter is encased and rigidity attached at the end of a steel tube which is 50mm external diameter ,thiness of metal being 5mm .the composite section is subjected to an axial pull of 100KN .find the stress induced in each metal and the extension on the length of 15m.
Answers
Explanation:
1. A circular rod of diameter 20 mm and 500mm long is subjected to a tensile force of 45 KN. the modulus of elasticity may be taken as 200 KN/mm2. Find stress, strain and elongation of the bar due to the applied load. [APR/MAY 2011]
Given data:
Load p =45 KN = 45 x 103 N
Young’s modulus E = 200 KN /mm2
Length of the rod, l = 500 mm
Diameter of the rod = 20 mm
Data asked:
Stress, strain, elongation CIRCULAR ROD
Solution:
Cross sectional area; A = πd2/4 =π x 202/4 = 314.159 mm2
Stress σ =load / area =45x103/314.5 = 143. 24 N/mm2
Strain, e = stress / young’s modulus =143.24/200x103 = 0.0007162
Elongation δl=Pl/AE = (45x103 x 500) / (314.159 x 200x103) = 0.358 mm
Result:
Stress σ = 143.24 N/mm2
Strain = 0.0007162
Elongation δl = 0.358 mm