As the Analytical Consistency Checks, Check Member Supports and Analytical Model Tools have been removed from the Revit platform, we would recommend that an Analytical Connectivity view is created within the model to help identify areas which require further amendment.

Some users may have existing templates with analytical connectivity views already defined.

If the template being used doesn’t contain a connectivity status filter, please see the later section Creating An Analytical Connectivity View for step-by-step instructions on how this is created.

Note : In addition to the use of colored filters to identify nodal connectivity, we would also recommend the use of the Validate command within Tekla Structural Designer after transfer to ensure correct connectivity has been achieved.

It should be noted that the default position for generated Analytical Members is to follow the location line of the structural instance.

If Constraint Offsets have been assigned onto Beam or Structural Column instances, this will affect the location line of the instance and therefore the generated Analytical Model position.

If Geometric Position offsets have been assigned onto a Beam instance, this will leave the location line of the object unaffected but adjust the physical representation.

We would recommend creating a view within your Revit model or template specifically for checking analytical model connectivity. If your model is based on the standard Autodesk templates then the 3D View: Analytical Model can be used however we would also recommend enabling the option to view Analytical Nodes within the Visibility/Graphics Overrides command.

NB. To help with the clarity of the created view, we would recommend disabling the option Show model categories in this view (Model Categories tab). Disabling this option will remove all physical objects from the view and leave only analytical objects being visible.

When using this view, you should be looking for areas where many nodes are located. These can be indications of a concentration of unconnected member ends.

We would recommend the use of a color-coded filter based on nodal connectivity. This can then be combined with the created Analytical Connectivity view to help identify problem areas within the model.

Analytical Nodes (and the associated instance Analytical Member) can be relocated using any view where Analytical Node categories are clearly visible. We would recommend adjusting the position of Analytical Nodes using an Analytical Connectivity view as described above as this should then also update the color coding of the node to suit the assigned filter.

To adjust an Analytical Node position, simply click and hold the left mouse button while hovering over an Analytical Node. Move the mouse onto a member providing support and then use a snap shortcut for the node location such as SE (Snap to Endpoint), SM (Snap to Midpoint) or SI (Snap to Intersection), before finally releasing the mouse button.

An alternative to this is to use the Align command (Modify tab). Please note that adjusting the Analytical Node position (and therefore the Analytical Member position) does not affect the physical position of the instance.

The default position for braces within Revit is to move the location line onto the center of the joined beam or beam/column intersection. As the Analytical Member is located at the location line, this can lead to a poor quality default analytical model being generated.

For example as shown in the example below, this can lead to eccentric analytical connections of beams and/or braces to columns, rather than concentric connection which the engineer would normally assume for such geometry, producing undesired analysis and design forces.

To avoid poor connectivity and eccentric analytical connections from occurring, Bracing Analytical Members are adjusted as follows:

1. If the start or end of the Bracing Analytical Member intersects with the start or end positions of a Structural Framing Beam reference line or Column Analysis member, that position is not adjusted.

   

   Bracing Analytical Member modeled to the intersection of the Structural Framing and Structural Column instances.

2. If the start or end of the Bracing Analytical Member lies within a distance of 24” or 600mm of the end of a Structural Framing Beam reference line or a Column Analysis Member, the Bracing Analytical Member is adjusted to suit the relevant position.

   

   Bracing Analytical Member created to the intersection of the Structural Framing and Structural Column instances as the end sits within the 24” tolerance.

3. If the start or end of the Bracing Analytical Member lies within a distance of 24” or 600mm of the midpoint of a Structural Framing Beam reference line or a Column Analysis Member, the Bracing Analytical Member is adjusted to suit the relevant position.

   

   Bracing Analytical Member created to the midpoint of the Structural Framing instance above as the ends sit within the 24” tolerance.

4. In other situations, the start or end of the Bracing Analytical Member will not be adjusted to a level in the Revit model.

   

   Bracing Analytical Member unadjusted as it does not meet any of the above criteria.

nb. For Bracing Analytical Members, please note that rule 2 takes precedence over rule 3.

Alternatively, the analytical member for the bracing member can be redrawn and associated manually using the Analytical Member and Add Association commands.

It may be noted that Analytical Panels are always drawn to the physical extent of the floor instance. In a number of cases, this will lead to the areas of the analytical panel being unsupported after transfer into Tekla Structural Designer (e.g. Composite slab objects). This is especially true if the boundary of the floor instance has been adjusted to cover the full flange of any supporting steelwork beams.

Although analytical panels can be adjusted in position by clicking and dragging the analytical node positions, we have found that this can also adjust the positions of adjacent analytical members, leading to connectivity and structural integrity issues. We would therefore recommend that panels are adjusted with care, and not at all if the adjacent analytical members are affected.

Available workarounds would be to either draw the Analytical Panel from scratch to suit the required analytical boundary and then associate it to the floor instance. Alternatively, do not include floor instances within the overall analytical model and instead generate them within Tekla Structural Designer.

Our recommendation is, if the floor instance will not be designed in TSD and is purely required for load decomposition purposes (e.g. metal roof or composite one-way slab for example), consider omitting the floor instances from the integration process, as slabs can be generated very quickly within TSD.

When using Tekla Structural Designer, it may be required to design very shallow slopes as flat for engineering efficiency reasons (to avoid the problem of modeling non-planar roofs or where sloping roofs are encountered for instance).

The Revit model would still need to be created correctly for BIM sharing and contract documentation purposes though.

When creating these items, we would recommend that Geometric Position offsets are used to model the slope of the beam. Geometric Position offsets leave the position of the location line unaffected with any generated Analytical Member also following the location line.

In situations where columns butt against continuous beams, we would recommend that the Attach Top/Base command to model the column to the underside of the oversailing beam is not used.

Use of this option can cause the integration process to return an error message when merging design results from Tekla Structural Designer. This is due to the parameter FAMILY_TOP_OFFSET_PARAM being flagged as read-only when attached to another object.

To ensure analytical connectivity, we would recommend modeling the column instance in an Elevation or Section view and using the intersection with the top of the continuous beam to define the upper extent of the Structural Column. This will ensure that the column instance will be physically shown joining to the underside of the oversailing beam, but also ensure that the two instances are analytically connected.

It should be noted that Analytical Panels created on Wall objects using the Create Analytical Model command are always generated at the center of the wall. This is due to a restriction of the Revit software and is irrespective of where the location line is defined on the Wall instance.

Please note that using the Attach to Floor option will affect the physical boundary of the wall and therefore the created Analytical Panel. We would advise against using the Attach to Floor option if intending to transfer the wall to Tekla Structural Designer to maintain analytical connectivity.

Structural Column instances do not contain Geometric Position properties that are held by Structural Framing instances (namely Beams). This means that the Analysis Member will always be initially generated at the center of gravity position.

We would recommend that Structural Column instances be moved into the correct physical location in plan views. The analysis wire can then be adjusted (moved) to a suitable position (such as a grid intersection position).

After creating the analytical model within Revit, it may be that the physical model is developed further, instances can be added, moved or stretched.

It should be noted however that after making these changes to the physical model, the created analytical model may not be automatically modified to suit the new positions.

To update the positions of the analytical model, use the Create Analytical Model command and the Update Existing option.