A stairwell is supported by two circular steel rods at one end. The other end supported above. The two steel rods are subjected to a total load of 12,800lbs. The rods are 24 ft long and E=30*10^6 psi. Select the rod based on the following specs. The rod deformation should not exceed 0.375 inches and the allowable tensile stress is 10,844 psi?

I used your advice on prior post still not ubderstanding where going wrong
could you please explain?

To select the appropriate rod for the given specifications, we need to calculate the maximum load that the rod can withstand without exceeding the allowable tensile stress and the maximum deformation.

Let's start by calculating the maximum load the rod can withstand without exceeding the allowable tensile stress. We can use the formula for stress:

Stress = Force / Area

where Force is the load applied to the rod and Area is the cross-sectional area of the rod.

To find the cross-sectional area, we can use the formula for the area of a circle:

Area = π * (Diameter/2)^2

Given that the two rods have a length of 24 ft, we need to convert this to inches (1 ft = 12 inches) and divide it equally between the two rods. Therefore, the length of each rod is 12 ft or 144 inches.

The diameter of the rod is not given, so we'll call it D.

Now, let's calculate the area of each rod:

Area = π * (D/2)^2

Next, we'll calculate the maximum load that each rod can withstand without exceeding the allowable tensile stress:

Force = Stress * Area

Given that the allowable tensile stress is 10,844 psi, we can substitute this value into the equation and solve for Force.

Now, we need to calculate the maximum deformation of the rod. For a steel rod under axial load, the formula for deformation is:

Deformation = (Force * Length) / (E * Area)

where Length is the length of the rod, E is the modulus of elasticity (provided as 30*10^6 psi), and Area is the cross-sectional area of the rod.

Substituting the values into the equation, we can calculate the maximum deformation.

Now, we need to compare the calculated maximum deformation with the specified maximum deformation of 0.375 inches. If the calculated deformation is less than or equal to the specified maximum deformation, the rod is suitable for the given specifications.

I hope this explanation helps you understand the process. If you have any specific calculations or steps that you are having trouble with, please let me know, and I'll be happy to assist you further.