Deformation, stress, and strain problem.

AI Thread Summary
A 24-inch diameter concrete column is analyzed under a wind uplift load of 50 kips and a compressive force of 120 kips. The axial compressive stress is calculated as 0.2653 ksi, while the axial tensile stress from wind action is 0.1105 ksi, leading to a net stress of 0.1547 ksi. The discussion emphasizes the need to determine deformation, strain, and the factor of safety to assess the column's integrity. To ensure safety, actual ultimate stresses should be compared to allowable limits. Proper formulas for deformation and strain under axial loads are recommended for further calculations.
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Homework Statement


A 24in diameter concrete column, at tenth story of an office building, is supporting the flat roof slab is subjected to a wind uplift load of 50.00kips while carrying a factored
compressive force of 120.0kips. the column is 10.00ft long. Assume elasticity of concrete
to be 4200ksi and the ultimate compressive and ultimate tensile strength as 2.400kis and 0.2000ksi respectively. Determine:


Diameter: 24 in
Wind uplift load: 50 kips
Compressive force: 120 kips
Colums length: 10 ft
Concrete elasticity: 4200 ksi

Area (A): 452.39 in^2


Homework Equations


a) The axial compressive stress from compressive force only
b) The axial tensile stress from wind action only
c) The net stress
d) The deformation of the column
e) The strain in the column
f) The factor of safety? Is the column safe? Check whether the roof is carried away or not?


The Attempt at a Solution


A = 0.2653 ksi
B = 0.1105 ksi
C = 0.1547 ksi

Sorry, but I am not sure if my answers are correct.
Also I don't know how to solve d, e, and f.

Thanks in advance.
 
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vac said:

Homework Statement


A 24in diameter concrete column, at tenth story of an office building, is supporting the flat roof slab is subjected to a wind uplift load of 50.00kips while carrying a factored
compressive force of 120.0kips. the column is 10.00ft long. Assume elasticity of concrete
to be 4200ksi and the ultimate compressive and ultimate tensile strength as 2.400kis and 0.2000ksi respectively. Determine:


Diameter: 24 in
Wind uplift load: 50 kips
Compressive force: 120 kips
Colums length: 10 ft
Concrete elasticity: 4200 ksi

Area (A): 452.39 in^2


Homework Equations


a) The axial compressive stress from compressive force only
b) The axial tensile stress from wind action only
c) The net stress
d) The deformation of the column
e) The strain in the column
f) The factor of safety? Is the column safe? Check whether the roof is carried away or not?


The Attempt at a Solution


A = 0.2653 ksi
B = 0.1105 ksi
C = 0.1547 ksi

Sorry, but I am not sure if my answers are correct.
Also I don't know how to solve d, e, and f.

Thanks in advance.
Your answers A and B look good, also C, but you should indicate for C whether net stress is compression or tension.

For deformation and strain, there are formulas you should look up for members under axial tensile or compressive loads.

For F, compare actual ultimate stresses to allowabale ultimate stresses to see if the column is safe.
 
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