Farrell wrote: > > Yeah, we are closer. My terminology may be less than ideal. I think the proper term to use >rather than shear force is shear stress. My terms are coming largely from my graduate >studies in structural geology (a few years back now!) - but forces are forces, and stresses >are stresses. I dont think I have a problem separating shear force with stress here. Thats cool. I think actually thats the distinction I am making by insisting on clarifying the difference in using the words "between" an "on" in this context. (ie shear force between, and shear force on.) >If it is not compression, and it is not tension, and you are talking about two parallel >planes of reletive motion (or force), then you have a shear stress. > > That is, of course, if I remember correctly! ;-) Shear stress is not just two parallel planes of relative motion or force... this is shear only when the stress itself is parallel to those planes. Says much the same thing as you do above I guess, but perhaps makes it easier to avoid misunderstanding ? In the case two plates coupled by a nail, the nail will be under shear stress, and whatever shear stress is apparent on the plates is only at the nail, exactly at and parallel to the cross section of the nail. Yes ? In the case of two plates coupled by being pressed together, fricton takes the place of the nail above and the result is shear stress exerted ON the two surfaces. The amount of shear stress here is dependent on the net angle of the sum of the forces involved... no ?? (We use vectors for this kinda thing eh ? ) In the case of two blocks of wood pushed together.... while this has two parallel planes of force (not motion) the force is applied perpendicular to the planes involved... ie compression (tensil ?) stress on the two surfaces of the blocks. > > Terry Farrell > Cheers ! RicB "The greatest impediment to real communication may in reality be the use of language" anon.
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