A round steel HSScolumn is subjected to an axial force of 50

A round steel HSScolumn is subjected to an axial force of 500 kN and is supported by a steel base plate and a concrete pilaster. The strength of the steel column and the concrete pilaster are (sigma_Fail)_Steel = 350 MPa and (sigma_Fail)_Concrete = 25 MRa. Calculate the required column thickness and base plate diameter. Use a factor of safety of 1.5 for steel and 2.5 for concrete.

Solution

Cross-sectiona rea of steel pipe = pi*(0.1^2 - (0.1-t)^2) m^2

Normal stress on steel plate = Force / area = 500*10^3 / [pi*(0.1^2 - (0.1-t)^2)] Pa

350*10^6 = 1.5 *500*10^3 / [pi*(0.1^2 - (0.1-t)^2)]

Solving this, thickness t = 0.00347 m or 3.47 mm

Bearing area = pi*r^2

Bearing stress = 500*10^3 / (pi*r^2)

25*10^6 = 2.5* [500*10^3 / (pi*r^2)]

Solving this, r = 0.1262 m or 126.2 mm