Solid Mechanics - Force in a bolted assembly

• oceanwalk
In summary, by using the given information about the bolted assembly and the properties of the steel bolt and brass tube, the resulting force in the steel bolt Fs can be calculated to be approximately 35 kN. This is determined by using the equation [sigma][/s] = [E][/s] [delta]/L and [F][/s] = [sigma][/s] * [A][/s], where [E][/s] is the Young's modulus for the steel bolt, [delta] is the screw pitch of 1 mm, and L is the initial length of the tube.
oceanwalk
A bolted assembly consists of a steel bolt A, a brass tube B and a nut C. The nut is turned so that it just secures the tube, and then is tightened one extra turn. Determine the resulting force Fs (in kN) in the steel bolt. The initial length of the tube is L = 158 mm, and the screw pitch is 1mm (the nut moves 1mm along the bolt for each turn). For the steel bolt, Es = 200 GPa, As = 28 mm2. For the brass tube, Eb = 100GPa, Ab = 142 mm2.
https://www.vista.ubc.ca/webct/RelativeResourceManager/Template/RspQ-ps-221-3-v1/ps-221-3-q19-1.jpg

Homework Equations

[F][/b]+[F][/s] = F (not sure about this because it's a bolt and not something placed between the nut like the tube)
[δ][/s]= [δ][/b]=δ = 1mm
[σ][/s] = [F][/s]/ [A][/s] = [E][/s]δ/L

The Attempt at a Solution

[σ][/s] = [E][/s]δ/L = 200*(1/158) = 1.2658GPa
[F][/s] = [σ][/s] * [A][/s] = (1.2658*10^9) * (28*10^-6) = 35kN

oceanwalk: What do mean by all the brackets and such? To correct typos, you can hit the Edit button (for 24 hours).
oceanwalk said:
[F][/b] + [F][/s] = F

Incorrect. Try again.
oceanwalk said:
[delta][/s] = [delta][/b] = delta = 1 mm
Incorrect. Try again.

1. What is a bolted assembly?

A bolted assembly refers to a type of mechanical connection where two or more components are joined together using bolts and nuts. This method of assembly is commonly used in construction, manufacturing, and various other industries.

2. How is force distributed in a bolted assembly?

The force in a bolted assembly is distributed through the bolts and into the surrounding components. The amount of force that each bolt can carry depends on its size, material, and the type of loading it is subjected to.

3. What is the purpose of torque in a bolted assembly?

Torque is used to tighten the bolts in a bolted assembly. It creates a clamping force that holds the components together and helps to distribute the load evenly across the bolts. This prevents the bolts from loosening and ensures the stability of the assembly.

4. How do you calculate the force in a bolted assembly?

The force in a bolted assembly can be calculated using the formula F = P/A, where F is the force, P is the applied load, and A is the cross-sectional area of the bolt. This formula assumes that the force is distributed evenly among the bolts.

5. What factors affect the strength of a bolted assembly?

The strength of a bolted assembly is influenced by various factors, including the size and material of the bolts, the number of bolts used, the type of loading, and the quality of the bolts and components. It is important to consider all these factors when designing a bolted assembly to ensure its strength and stability.