BIM & BEAM

Use shared nested families

Some elements, e.g., bolts or piles, are the assemblies of a host family, e.g. a steel connection or a pile cap, and they might be nested/ used in multiple families. People usually expect them to be scheduled independently.

Those elements should be created as "shared" families before they are nested into the hosts to enable them to be "shared" among hosts. The example is shown as fig 1,

 
 Fig. 1, Family Category and Parameters' settings of a shared steel pile

If a host is nested with shared components, after it being loaded into a project, each nested shared assembly will be shown separately in the project browser under its respective family category, shown as fig 2. As a result, the shared nested families (e.g., the steel pile) could be scheduled independently, shown as fig 3.

  Fig 2, project browser shows the nested shared steel piles after the pile cap is loaded

 
Fig 3, Pile cap scheduling, shared nested components are schedulable.

Thanks

Wai

Create Revit Site with Google Earth Surface

Autodesk labs site provide "Google Earth ^TM Extension"for AutoCAD, Architecture, Civil 3D, Map 3D, the usages of the tool are:

• Import Google Earth image to .dwg applications (AutoCAD, Architecture, Civil 3D, Map 3D)
• Publishing 3D DWG Models to Google Earth ^TM
• AutoCAD Drape a grayscale Google Earth ^TM image onto a 3D mesh in AutoCAD applications

The 3rd function provide a method to import the elevation data for the current Google Earth view into AutoCAD as a mesh, then one can link the site .dwg as a reference to create Revit site, here are the steps:

1. Launch AutoCAD (or Civil 3D, etc), do as per the guide (please refer to page 8-11 of the Google Earth ^TM Extension white paper, shown at the bottom of this article) indicates. Here are the results,

Google Earth TM Site
Imported mesh (.dwg file)

 

1. Launch Revit application or open a Revit project file (.rvt), link and put the .dwg object onto the target level, adjust the location, size (scale factor) if necessary.
2. Activate the Mass & Site tap, create "Toposurface"

    
   

3. Choose "create from import\select import instance" option and select the linked dwg file.

    
   

4. Here is the result in Revit GUI,

 

Note,

Google Earth ^TM Extension downloads site: http://labs.autodesk.com/utilities/google_earth_extension_beta/term_and_condition/

Google Earth ^TM Extension white paper:

http://labs.autodesk.com/files/201_300/205/file_205.pdf

Double Shapes- Analysis vs. Modeling

In Revit Structure, the structural beam, column and brace are regarded as bar elements, and the analytical mode lines join with one another at the nodes, shown below,

        

For some steelwork however, the joints require the elements not to be overlapped with one another while two or more elements are connected, e.g., as the following image indicates, two C shaped elements are placed in parallel to bearing the forces or bending moments. If two beams are put there, there will be two parallel analytical lines from one node to the next, and it will cause the analytical error.

To solve the issue, two steel elements are created in one family, and a spacing is set to control the horizontal offset of the beams, shown below. As a result, both modeling and analysis purpose are satisfied in the project.

Framing template/How to disable auto setback

Framing Template

There are 2 different templates in the package:

Template Type #1: Structural Framing - Beams and Braces.rft (for 2 point placement beams and braces)

• Reference planes usage

  Left/Right - Extents of the geometry curve as shown by the blue dot when selected, which control the length of framing.

  Member Left/Member Right – Physical edge of the geometric extents, and which control the cut length of framing.

  Stick Symbol Left/ Stick Symbol Right – Extents of stick representation when symbolic representation is set to "From Family".

  
  
• Behavior in project
  • The topmost point of the framing will attach to the current level automatically.

    Also, the insertion point can be changed (if needed) using "z-Direction justification" parameter.

    
    
  • Have the option to add rebar, but only can add reinforcement to the regular shape framing.

 

Template Type #2: Structural Framing – Complex and Trusses.rft (for type based length families)

• Behavior in project
  • Relative position with current level will be based on the "insertion point" which is defined in the family editor. Shown below,
    
    
  • Have NO option to add reinforcement.

 

Disable auto setback

For the beam that is created based on the "Structural Framing - Beams and Braces.rft", the geometry cut back is controlled by reference planes - Member Left/Member right and the Structural Material Type, as well as the boundary box of the geometry the beam is connecting to.

Predefined setbacks are as listed below.

Steel = ½" (12.7mm)

Concrete = ½" (12.7mm)

Precast Concrete = ½" (12.7mm)

Wood = 0" (0mm)

Other = ½" (12.7mm)

Shown as:

Sometimes, users don't want the auto setback and want to control the beam precisely from the column center, for this situation, predefined setbacks can be over-ridden in the definition of family by constraining the ends of geometry to the reference planes – Left/Right, which are the ones that control the end of the geometry curve as shown by the blue dot when selected. In this case, cut length will always equal to length.

Thanks

Wai

Concrete Beam Hidden Line Display Parameter

In Autodesk Revit Structure, we can get different hidden lines by setting a parameter called: Display in Hidden Views

Use the following case to explain how to:

There is a floor and a T shape beam under the floor (See Figure 1).

                                                (Figure 1)

Select the beam and click edit family. In beam family editor, open family category and parameters dialog, for parameter "Display in hidden views", there are 3 options (See Figure 2):

1. Edges Hidden by Beam Itself

2. Edges Hidden by Other Members

3. All Edges

 

                (Figure 2)

Let's apply the 3 parameters and compare the differences:

1. Edges Hidden by Beam Itself, only show beam edges in hidden line which are hidden by beam itself (See Figure 3)

                                                (Figure 3)

2. Edges Hidden by Other Members, only show beam edges which are hidden by floor (other member) (See Figure 4).

                                                (Figure 4)

3. All Edges, represents edges including 1 & 2 (See Figure 5):

                                               (Figure 5)

You can also find this parameter in concrete column family editor as well.

Revit Structure 2010 Slanted Column Parameters

Slanted columns are becoming more and more common in larger high-profile structures. The architectural forms that engineers are being required to support are getting more complex.

Engineers and drafters can now create slanted columns using the same column families they have used for vertical columns, which include not only physical characteristics, but also analytical as well.

The avi: http://revit.downloads.autodesk.com/download/Structure2010/Blog/Slanted Columns Parameters.avi will demonstrate how to utilize the tool and explain the parameters within the element properties to show how they will affect the location of the slanted columns to the supported members.

These new Slanted Column properties include the following:

- Column style parameter

• Slanted – Angle Driven
• Slanted – End Point Driven

- Column Cutback

    Beam/Column Joins editor

- Column Joins parameters

• Top/Base Attachment Type
• Top/Base Attachment Distance
• Top/Base Attachment Referenced End
• Top Geometry Treatment
• Base Geometry Treatment
• Offset From Attachment at Base
• Offset From Attachment At Top

- Column Attachments parameter

• Move Top With Grids
• Move Base With Grids

- Cross Section Rotation parameter

 

Black Level vs. Blue Level

When importing structural model, the levels show black as Fig1. In the project browser, Level 3 & Level 4 will not show up.

 

What's the difference between black and blue levels? How to turn the levels from black to blue?

The black indicates the level is not mapped to any floor plan, while the blue means the level is mapped with a floor plan.

To map a floor plan to a level, here are the steps,

• Go to the View tab> Create panel> Plan Views> Structural Plan

• From the New Plan dialog, select the levels for which you want to create new Floor Plan Views.

 

Go back to South View, the black levels turn to blue, and in the project browser, the Level 3 & Level 4 will show up.

  

“Do Not Break At Inserts” type parameter for a wall foundation with continuous footing

Hi All,

Just want to share a little tips & tricks with you.

One of my users was trying to create some openings touching the bottom of a wall foundation with continuous footing. The methods that he used to create the openings were:

1) Wall Opening tool

2) Edit Profile on Wall Sketch

He then went to the Wall Foundation Type Properties and try to use the "Do Not Break At Inserts" parameter:

 

However, as illustrated below he realized that regardless of whether this "Do Not Break At Inserts" is checked or not, he did not see a difference in its behavior. So both of his previous methods of creating openings by thinking that would be an insert and the footing would not break at them if they broke the bottom of the wall, but it appeared to have no effect:

So what does this parameter actually do?

This user approach and thinking was good, except that currently the Wall Opening or Edit Profile on Wall Sketch tools will not be affected by this "Do Not Break At Inserts" parameter.

Currently, this "Do Not Break At Inserts" parameter would only work if the openings are created by using the Windows and Doors .rfa family, for example:

3) Door-Opening.rfa

4) Window-Square Opening.rfa

5) Opening-Door.rfa (as Generic Model)

6) Opening-Window-Square.rfa (as Generic Model)

Thanks

Wai

What effect this Cap family parameter has on a Structural Foundation family?

In the last several months, I got some emails from customers asking what effect this Cap family parameter has on a Structural Foundation family?

 

This parameter is designed to determine the elevation of the bottom of the footing.

If Cap is selected, the Bottom Elevation will be taken from the "Topmost Bottom-facing Face".

If Cap is not selected, Bottom Elevation will be taken from the "Bottommost Bottom-facing Face".  To see this, refer to the following picture:

 

 From the below picture which is captured from the project file, we can easily find that the value of  "Elevation at Bottom" is different between the "Cap" checked and unchecked.

Slab Edge Hidden Lines Display

Back in February/March 2008, during our Revit Structure 2008 Beta testing period, there was a discussion among our Beta testers (from different countries) about the slab edge hidden line display. In fact, the standard or culture of displaying slab edge hidden lines on plan could be different from country to country.

For example, many USA companies have a standard to show the inside (or bearing) line to be displayed for slab edges.

However, some other countries users have also told us that their standard is to display both/all lines which is:

 

I would like to share a technique with you in Revit Structure 2009 of which one of our QA expert Joe Charpentier has explained in the Beta discussion forum an option, to be invoked via the Revit.ini file, that can change the display of hidden lines. Quote:

"By default, the inside (or bearing) line will be displayed for slab edges.

In the official release of Revit Structure 2009, we are providing an option, to be invoked via the Revit.ini file (typically located at C:\Program Files\Revit Structure 2009\Program), that can change the display of hidden lines.  This is similar in behavior to the "Show hidden lines" options for beam families.

Add the following section heading and variable names to the Revit.ini file, if it doesn't exist already:

[Graphics]
HiddenSlabEdge=All

Possible values for HiddenSlabEdge variable:
"All"  - Show all lines from a slab edge
"Itself"  - New default behavior, the "Bearing" or lower edges
"Other" - The edge intersecting with the slab, (Beta 1 and 2 Behavior)
"None" - Show no hidden lines for Slab edges (r2008 behavior)

Note that this is not set for the project, but for the session of Revit.  That is, if you open a file with a certain variable setting, that will not prevent the project from being displayed differently if opened in a different install with a different setting."

Thanks

Wai