Shear wall analysis

[Jummybear]

Hi,

I have a few questions about shear wall analyses and design.

I have 2 test models of the same wall: test model 1 is made as 1 wall, test model2 is made of small walls but global geometry is the same. I suppose that small difference in results is caused by slightly different meshes. Reduced results for panels is also not an option in model with 1 wall only.

Now questions:

1. Please confirm, that shear force and shear stress In wall type models (not plate) I can get by using Membrane forces-N in xy direction and stresses - s xy direction, both in maps-detailied dialog box.

2. Please confirm, that results in reduced results for panels are reduced to panel cut length, not to 1m. See pic Q2 and Q3.

3. Why there is no reduced stress to panel cut length in the reduced results for panels table, see pic. Q1?

Link to test models https://www.dropbox.com/s/t7tcq3hxm00d5ql/ARSA%20Forum_test.zip?dl=0

[Pawel.Pulak · Accepted solution]

Hello,

explanations to your questions

1. Please confirm, that shear force and shear stress In wall type models (not plate) I can get by using Membrane forces-N in xy direction and stresses - s xy direction, both in maps-detailied dialog box.

Yes. As concerns using sXY stresses to estimate in-plane shear please pay attention to the layer (middle/upper/lower) in case of any non-zero flexural out-of plane effects.

2. Please confirm, that results in reduced results for panels are reduced to panel cut length, not to 1m. See pic Q2 and Q3.

Yes, results in reduced results for panels are reduced to panel cut length (cuts at the edges or at the centroids of panels). It is suggested by the unit - kN and not kN/m for NRx in picture Q2

3. Why there is no reduced stress to panel cut length in the reduced results for panels table, see pic. Q1?

I do not understand what you mean there. 

If you mean some incoherences in pic Q1 here are the explanations:

- reduced results for panels shows results corresponding to "smoothing within a panel"

- average shear stress tR is calculated according to the formula from Help: tR = TRy/e/(Lc-e/2), where e is thickness (250mm), Lc is cut length (940mm for this cut). As it can be seen there the effective length of the cut is reduced there by e/2

Average shear stress estimated from the diagrams on cuts uses the full length of the cut - without reduction.

I have shown it on the screen capture below.

 

And some additional note related to pic Q3 and sRo, sRe values.

As it is described in Help and shown on the screen capture above these extreme stresses are calculated using reduced force NRx and reduced moment MRz assuming linear distribution of stresses along the cut (beam analogy). As it can be seen in pic Q3 this distribution in reality is not quite linear (like the minimum -4.78 not exactly at the end of diagram) so it may result in some incoherences when comparing these results.

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Regards,

[Jummybear]

Thx Pawel!