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 a suitable rod, we need to determine if the given specifications for deformation and allowable stress are satisfied. Here's the step-by-step process:
1. Find the cross-sectional area of the rod:
The cross-sectional area (A) of a circular rod can be calculated using the formula A = π * r^2, where r is the radius of the rod. Since the rod is circular, both rods will have the same cross-sectional area.
2. Determine the load on each rod:
Since the total load is evenly distributed between the two rods, each rod will carry half of the load. Thus, the load on each rod is 12,800lbs / 2 = 6,400lbs.
3. Calculate the tensile stress on the rod:
Tensile stress (σ) can be calculated using the formula σ = F / A, where F is the load and A is the cross-sectional area. In this case, σ should not exceed the allowable tensile stress of 10,844 psi.
4. Calculate the deformation of the rod:
The deformation (δ) can be calculated using the formula δ = (F * L) / (A * E), where F is the load, L is the length of the rod, A is the cross-sectional area, and E is the modulus of elasticity.
By comparing the calculated tensile stress and deformation with the given allowable values, we can determine if the rod meets the specifications. If the calculated values do not exceed the allowable values, the rod is suitable. Otherwise, a different rod with the required properties should be selected.
If you provide me with the specific calculations you have performed and their results, I can help you identify where you may have gone wrong.