Can someone please explain in detail shear webbing, why use it, can we do without it, what happens if you don't use it. etc.

Thanks

Shear webbing is any solid plate verticle member between the upper and lower spar cap in a wing. It is like the verticle part of an I beam.

Its principle purpose is to keep the upper and lower spar spread apart by a fixed amount. This lets the beam formed by the upper and lower spar remain at its design strength. Without the shear web, under high loading conditions the upper spar may fail in buckling and the lower spar may creep up in to the rest of the structure. If the loads are low enough you don't need them

The Sig Kadet LT 40 wing is a fine example the shear webs stop about 3/4 of the way out to the tips because the bending loads at the wing tips are less.

HTH
Tom

Major Tomskir had it 100% correct. I am posting so I can add in a diagram to illustrate what he said. The only thing I will add is that the strength of sheer webbing comes from the grain of the wood used for the webbing. The grain must run vertically or there will be no added strength.

Hope this helps

Ken

Flybug ,take the time to put it in. It will save you,from, being sorry later.

To add to Ken's drawing, imagine that you have a top and bottom spar connected at the wing root.

If you lift both spars (As the air is trying to do) the two spars will move side-to-side with each other. This "Shearing" motion is what is prevented by the Shear Webs