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mhdhamood

Etabs Manual Meshing Problem

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ENGINEERS;

I WILL LOOSE MY BRAIN FROM ETABS. 

I DECIDED TO MAKE MANUAL MESHING FROM AREA ELEMENTS BESIDE EACH OTHER AND EVERY HING WAS FINE .

BUT AFTER DEVISION SAY 7*7 ELEMNTS FOR EVERY BIG ELEMENT AND MAKING ETABS CHECH..................THEN 500 ERROR MESSAGE THAT ALL ELEMNTS ARE CLOSE TO EACH OTHER.  WHAT ARE GOING...... SOMEONE TELL ME PLEASE...... I WILL LOST MY WORK

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shaker,

 

Your attached image gives a very strange look, as it does not appear to have a regular pattern of supports for slabs. Moreover, I don't see any kind of regular building frame system in it.

 

What kind of structure it is?

 

Can you attach text input (.$ET) file  of your model?

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Dear shaker,

 

The information provided by you so far, does not clarify what type of structural system you are using for your building. It is not clear about your structure, whether it is a framed structure (using beams and columns for load transfer), or load-bearing wall system.

 

Moreover, you have not attached Text Input File of your model, therefore my comments are general, and keeping in view the information you have provided, as well as whatever I am able to extract from it.

 

As far as ETABS warning messages are concerned, you may use any of the following approaches:

 

1. Go to all the locations indicated warnings about, and correct them one-by-one manually.

 

2. Re-organize your model, as explained in following steps:

 

a. Establish the locations of all the columns and beams, if it is frame-type structure (or slab supports, if you are using a load-bearing wall system). Make sure that your columns properly aligned in each grid along both horizontal axes. That is, all columns in one line or along one grid are exactly in line with each other. (You may verify this by viewing the columns in each grid, using  two windows side-by-side, one showing Plan view and the other Elevation views one-by-one.)

 

b. Once all of your columns are aligned, check the grid elevations one-by-one to make sure that all the beams along a grid line are connected exactly to the column joints at both ends. (If you are using load-bearing system, you will need to align all the 'slab edge supports', instead of columns & beams.)

 

c. Now, it would be better to delete the slabs, not aligned with supports or beams, and redraw them carefully, using proper snap options.

 

d. Use auto-meshing options, or if necessary, mesh the slab manually. In manual meshing, you must be very careful in that:

       (1)  Number of elements, selected for each slab edge is such that the element shape is as near to the square shape as possible.

       (2) There should be preferably even (multiples of 2) elements on each edge.

       (3) You should have equal number of same width elements, in the length common to two adjacent slabs.

       (4) End points of adjacent elements on both side of slab edge, perfectly match (VERY VERY IMPORTANT). 

       (5) Dimensions of mesh elements should be within the limits, prescribed by ETABS.

 

I personally like & recommend the second option, whenever there are a lot of warning messages, similar to your case.

 

HTH

 

Regards. 

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