Floor construction & 3D

[nering]

I have to model concrete waffle slabs - anyone has any ideas?

I tried adding, subtracting, but all of those take forever. Tried using the repetitive unit tool, but it doesn't look right - is there a more efficient way to do it?

The ultimate goal for it is to be a solid item, that can be exported into IFC and sent to consultants.

Any tips?

Thank you in advance.

[bcd]

It's a repeating pattern?

Create one of the modules using solid subtraction.

Edit> Duplicate Array. Delete the additional modules to conform to the floor plan. Select All and Model>Add Solids.

Modify>Convert to Generic Solids

AEC>Create IFC Entity

[nering]

The file got enormous when I tried doing that and it took many hours.

I attached the file I started out with and used these solids to subtract from the 22" tall floor slab.

[bcd]

I just extruded a rectangle 22" moved it up a tad and subtracted all your solids from it. It's just a couple of mb and takes no time. Must be something amiss.

[Jeffrey W Ouellette]

Natalie,

I tried a few experiments recreating a slab from the 11th floor of your model.

I tried a couple different methods, all trying to lead to the same end, a monolithic waffle slab.

In both 2009 SP3 and 2010 SP1, the waffle slab is a large collection of either solids operations (892 subtractions) or surface clips and one extrude. The resulting file is 15.7 MB.

Any attempt to model the floor slab at this level of detail will result in a large file with editing of the waffle slabs being very slow.

Converting it to a generic solid, after getting the waffle slab geometry correct did reduce the size of the slab from 15.7 MB to 3.8 MB, and make it more "responsive", but it is no longer editable.

Bear in mind, I'm using a 1st gen MacBook Pro with an Intel Core Duo chip. It's definitely not the most powerful or fastest machine out there anymore.

The only advice I would have is reconsidering the need to model the waffle slab and just model and export a simple floor slab. Leave the waffle cells as 2D symbols. You could then supplement the IFC model with DWGs that show the location of the waffle coffers, for those that need to know. If your consultants feel it is necessary, they can try modeling the waffle cells.

[billtheia]

I suspect you'd wind up with a smaller file if you model one waffle, make a symbol out of it, duplicate array.

[Jeffrey W Ouellette]

Natalie,

You may be able to get better performance AND smaller size by using Solids Additions INSTEAD of Solid Subtractions. Robert and I have been experimenting this morning and I'll try to mock up the 11th floor for you to demonstrate.

Edited November 5, 2009 by Jeffrey W Ouellette

[Jeffrey W Ouellette]

Natalie,

Please look at the attached files and images for the results of using Solid Additions, rather than Solid Subtractions, to create the waffle slab.

1) Create a Floor object of the basic supported slab, the thickness above the waffle coffers

2) Using the Wall Styles and Wall tool, create walls that are the width and depth of the needed primary concrete support beams under the slab above. Join the walls so it looks like a monolithic grid in Top/Plan view.

3) Create a 2D polygon grid of the shape and extents of the waffle coffers within each bay, between the wall/beams. This polygon grid can be made by drawing rectangles of the appropriate length and width of the bottom of the coffers. Then use Taper Extrude... command to created a 3D waffle grid, with a negative angle value (in this case -5.61).

4) Place four Loci at the corners of the bay, where the walls intersect. This is to help locate the object when it is a symbol.

5) Select the Loci and the 3D waffle grid and create symbol, using one of the loci as a insertion point. If you wish to make a 2D representation of the grid, just enter the group on the Tapered Extrude and copy the polygon. Exit Group and then paste the polygon in the correct place. Change the attributes, as desired.

6) Place the new waffle grid in each bay formed by the walls/beams.

7) Verify the Z-value of all parts in a Front view

8) Select all and select the command Add Solids.

9) Then use the IFC Data... command to add the IfcSlab entity to the resulting object.

10) Note that you can still edit the components of the slab by Enter Group.

The resulting slab is less than 1/3 the size (4.8MB vs 15.7MB) of the same waffle slab created by using Solid Subtractions of the waffle coffers from a deep monolithic slab/floor.

(BTW these are VW2009 SP4 files)

Edited November 5, 2009 by Jeffrey W Ouellette