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I saw this monitor clamp crush a hollow Ikea desk: enter image description here

To prevent this, the load of the clamp should be spread. But spread how? Say I had a 1.5mm thick sheet of steel.

  1. If I placed it here, would the same thing have happened, but this time the crack would have run along the long side of the steel sheet? Does the fact the width of the steel doesn't go past the front of the clamp make a difference?

enter image description here

  1. If I moved it forward slightly, I predict it would have prevented damage to the desk. But why? Isn't the load spread amongst the same amount of surface area compared to the above image?

enter image description here

  1. Would it make a difference if the steel sheet was placed like this? I think the steel sheet would have a sort of lever effect as the centre of gravity is closer to the area covered by the steel sheet load spreader

enter image description here

  1. Does the tightness of the clamp affect anything? eg loose clamp, exaggerated for effect, the two red dots are where the force is concentrated:

enter image description here

tight clamp, the red lines are where the force is spread:

enter image description here

Or would there still be a concentration of force at the red dots as the monitor moves the centre of gravity and adds a torque effect?

This question is not the same as Mounting a monitor arms clamp on an IKEA desk, what can I use to distribute the load? ; that question asks how, this question is more specific as it asks why.

A G
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  • You link to a question with the solution, use plywood or similar to spread the load. Cheap cr*p does not support what is effectively a point load. If it was a 2" thick solid mahogany desk then there would not be an issue. – Solar Mike Jan 07 '21 at 16:37
  • I'm confused by your last statement. Your entire question is about how to properly distribute the load, which the linked question answers. Then, your last statement say this is about "why", yet you seem to have a _very_ good grasp of _why_ this happens. Care to clarify your last statement? IMHO, the pictured failure was likely due to under tightening of the monitor stand clamp allowing it to tip when the large monitors were moved forward. – FreeMan Jan 07 '21 at 16:49
  • No - the question is quite clearly "how", not "why". The answer to "why" is as commented by @SolarMike. The "how" is in the dupe. – SiHa Jan 07 '21 at 17:25
  • Tightening it down so there's no gap for it to tilt would help. Your illustration shows exactly what a lose clamp does; as it leans forward, the weight is forced into a smaller point of contact on the desk surface. But I would think even a particle board desk would hold up the weight better than yours has. – Phaelax z Jan 07 '21 at 18:28
  • I want to know if there is a difference between placements 1,2 and 3, since it is the same surface area spreading the load. It was closed on the physics SE as it was deemed an engineering/diy question. @Phaelax z: if I tightened as in the bottom image, would there still be forces acting at the ends (where the red dots would be)? If there were, then placement 3 would appear to be the best option? I exaggerated the tilted diagram for illustration. – A G Jan 07 '21 at 18:51
  • Can you possibly use two monitor clamps? That one has not only a small clamp size but also a huge cantilever load because it has to reach out so far to hold the monitors apart. There is probably a couple hundred pounds of point force on that little clamp, so no wonder it punched through. – Harper - Reinstate Monica Jan 07 '21 at 19:50

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