Question

Nornas Class-door wall cabinet http://www.ikea.com/us/en/catalog/products/00282250/

You go shopping at Ikea and come home with the cabinet pictured. You wish to hang it on your wall, but you have only two screws and are worried that they might not be strong enough.

1. Where should you attach the screws to the cabinet? Why?

2. What will the force on the screws be when the cabinet is loaded to capacity?

3. If you are screwing into a wall made of 3/8 inch wallboard, and you are using a 1/8inch diameter polly fasteners (see http://www.powers.com/pdfs/plastic/02105.pdf), will it hold? How do you know? If they will not hold, how are they most likely to fail?

Answer 1

Part 1)

On the top corners of cabinets to balnce shear (gravitational pull) and moment (to restrain it from rotating)

Part 2)

It wil be equally distributed if the cabinet is loades uniformely and not at a single point.

Total load = 13.2+5*3 = 28.2 kg

Total load force = mg = 282 N

Case 1. Uniformly distributed

Force on each screw will be 282/2 = 141 N

Case 2. Just below one support.

Force on the vertically upwards will be 282 and on other will be 0 N

Part 3)

it wil hold if the capacity of the fasteners is greater than the applied load.

Else it will crack in shear.

Please provide the value to get the more accurate answer. as i am not able to see the value via link provides by you.

Need value of screw and wall strenght. It will fail if strenght of any thing is less then 141 N.