Question

A composite member is made of a hollow steel pipe with an inner diameter of 12” and wall thickness 1”. The hollow steel pipe is filled with concrete and subjected to a compressive force of 120,000 lbs. The member length is 25’. The modulus of elasticity of concrete and steel are E_c = 3,600,000 psi and E_s = 30,000,000 psi, respectively. Calculate the axial and compressive loads resisted by the steel and concrete.

		Fconcrete = 45000 lbs ; Fsteel = 75000 lbs;
		Fconcrete = 30000 lbs ; Fsteel = 90000 lbs;
		Fconcrete = 90000 lbs ; Fsteel = 30000 lbs;
		Fconcrete = 75000 lbs ; Fsteel = 45000 lbs;

Answer 1