RELATIVE RIGIDITY IN WOODEN SHEAR WALLS
RELATIVE RIGIDITY IN WOODEN SHEAR WALLS
(OP)
I know with masonry shear walls you take the height divided by the depth plug the answer into a chart and get the R value. I also know that rigidity is the reciprocal of deflection. Is the rigidity of a wooden shearwall the reciprocal of the deflection? When designing wooden shear walls, how would you calculate relative rigidity?





RE: RELATIVE RIGIDITY IN WOODEN SHEAR WALLS
h
woodengineer
RE: RELATIVE RIGIDITY IN WOODEN SHEAR WALLS
RE: RELATIVE RIGIDITY IN WOODEN SHEAR WALLS
Mike McCann
McCann Engineering
RE: RELATIVE RIGIDITY IN WOODEN SHEAR WALLS
RE: RELATIVE RIGIDITY IN WOODEN SHEAR WALLS
Mike McCann
McCann Engineering
RE: RELATIVE RIGIDITY IN WOODEN SHEAR WALLS
The "ratio" between the actual rigidity and relative rigidity for the respective LRFS should be the same.
RE: RELATIVE RIGIDITY IN WOODEN SHEAR WALLS
Mike,
I did ask him why. He didn't know.
Whyun,
Yes, you are correct. And I guess ultimately it really doesn't matter what factor they used. The relative "stiffness" to be applied to the shearwalls can be determined from the reciprocal of the deflections of the shearwalls. I saw their calcs and was just curious.
Thanks to everyone again.
RE: RELATIVE RIGIDITY IN WOODEN SHEAR WALLS
It is not the reciprocal of the deflection of the shearwalls. It is the reciprocal of the deflection of yoru shearwall divided by the reciprocal of the deflection of the shearwall that you arbitrarily set as having a relative rigidity of 1.
RE: RELATIVE RIGIDITY IN WOODEN SHEAR WALLS
RE: RELATIVE RIGIDITY IN WOODEN SHEAR WALLS
RE: RELATIVE RIGIDITY IN WOODEN SHEAR WALLS
Am I missing something? Even the SEAOC design manual, in my opinion, seems to incorrectly distribute the loads based only on the wall lengths. Any thoughts?
RE: RELATIVE RIGIDITY IN WOODEN SHEAR WALLS
while it is technically correct to distribute the shear load to walls in the same line based on rigidity, it becomes a moot point with wood shearwalls as the height to width is generally limited by the 2:1 ratio. With this configuration the "bending" portion of the stiffness contributes less than 8% of the total wall stiffness,so when using identical panel designs in the same wall line, the rigidity is almost directly proportional to length anyway.
If you design a shearwall that has a smaller ratio then you would need to take the rigidity into account, but the 07 CBC "kind of" does this for you by requiring what would be a stiffer panel, via strength reductions, at locations with smaller ratios.