Screws Shaking Loose: Vibrations Explained

[Johnleprekan]

Can anyone explain how vibrations actually shake a screw loose from a shelf? What is happening there?

 

[truesearch]

My suggestion !...screws are essentially 2 inclined planes wanting to slide past each other. It is only friction that prevents this happening. If there were no friction screws would have a tendency to unwind under any load at all.
I would imagine that constant vibration enables slippage to occur and this is bound to result in screws getting slacker. I have never come across vibration making screws tighten up !

 

[mkillman]

Expansion and contraction

as the sound waves pass through the object in question it expands and contracts this action is what's turning your screw

Wood expands screw loosens up some
Then then wood contracts but the screw is in a slightly diffrent place so it becomes a question of least resistance is it easier to sheer metal into wood or turn the screw?

I could be wrong but that's my take on it

 

[Johnleprekan]

Thank you.

 

[pmacias]

Vibrations can definitely cause screws to become loose from a shelf. This is due to a phenomenon called resonance, which occurs when an object's natural frequency matches the frequency of the vibrations. When this happens, the object begins to vibrate more intensely, which can cause it to become dislodged or loosen from its original position.

In the case of a screw in a shelf, the vibrations from nearby sources such as machinery, footsteps, or even music can cause the shelf to vibrate at a certain frequency. If this frequency matches the natural frequency of the screw, it will begin to vibrate and eventually loosen from the shelf. This is because the vibrations are causing the screw to move back and forth, creating small movements that can gradually loosen its grip.

Additionally, the repeated vibrations can also cause wear and tear on the screw and the shelf, making it more susceptible to loosening over time. This is why it is important to properly secure screws and regularly check for any signs of loosening in areas where vibrations are present.

In summary, vibrations can shake a screw loose from a shelf due to resonance, where the frequency of the vibrations matches the natural frequency of the screw, causing it to vibrate and eventually become dislodged.