Enhanced Reinforcement and Analytical Model Control
As with the last release of Autodesk® Revit® Structure, the newest release also concentrates on reinforcement and analytical enhancements. This article will only be looking at new features that pertain to Revit Structure and will not include any of the Revit platform enhancements that have been included in this release.
Figure 1 below shows a new presentation setting for reinforcement. This controls how the rebar is shown in plan and in section; this does not affect 3D views.
Figure 1: Reinforcement settings
Below, Figure 2 displays the three settings that are available for both plan and section views. These are: Show all, Show middle, and show first and last.
Figure 2: Reinforcement settings—results
Revit now allows you to number rebar with different numbering sequences. These sequences are called partitions, and they can be named as well. Figure 3 shows where to access the reinforcement numbers dialog box.
Figure 3: Reinforcement numbers
Once you place reinforcement in your model it will appear in the reinforcement numbers dialog, allowing you to assign a partition number as well as rebar number sequence. Any changes made will be automatically reflected in the properties of the rebar placed in your model.
Figure 4: Reinforcement Partitions and Numbers
Fabric reinforcement is numbered separately from rebar numbers, so you can effectively have Rebar and Fabric Numbers starting with 101. At the top of the dialog you will see that you can control the minimum number of digits for reinforcement numbers.
The numbers for the rebar will automatically match for the rebar/fabric of the same type/size/shape placed in your model.
The Remove Gaps function all the way to the right side of the Reinforcement Numbers dialog box is used to close the gaps in the numbering. For example if you have Partition P1 which has rebar numbers 1,2,3,4,5, and 6, then you delete rebar types 2 and 4. Revit can close the numbering gap and make the numbering sequence read 1,2,3,4. This change would automatically update rebar properties in the model.
Fabric Sheet Placement
Fabric sheets have been added to reinforce sections of concrete for walls, floors or slab foundations. Place fabric sheets on floors in a plan view and on walls in elevation view.
Figure 5: Fabric sheets
When you place a fabric sheet it will automatically snap to the rebar cover settings of the host object. If there is already another fabric sheet on the host when you place another fabric cover, it will snap to the edges of other fabric sheets, lap splice or midpoint of other fabric sheets.
Figure 6: Fabric Sheet placement
There is a grip on the fabric sheet that allows you to change the origin point. You cannot rotate the sheet once it is placed; however, if the host rotates so will the fabric sheet. Figure 7 below shows the type properties of a placed fabric sheet that allow you to control reinforcement spacing and fabric sheet size.
Figure 7: Fabric sheet type properties
Top of Foundation Elevation Parameter
Structural Foundations now have a new parameter that allows you to tag the top elevation of footings and foundations.
Figure 8: Top elevation parameter
Figure 9 below shows the parameter added to a foundation tag. Then the tag was applied to an isolated foundation.
Figure 9: Top of footing elevation tag
Analytical Model Local Coordinate System
Local Coordinate System (LCS) for analytical model elements is an important factor during structural design. LCS is used in many steps of the design process. In the past users were not able to view the LCS on a structural element. It is now a subcategory in visibility graphics.
Figure 10: LCS subcategory
Figure 11: LCS shown on columns and beam
The LCS helps with the following:
- To define axes of selection characteristics.
- The orientation of loads and supports.
- Defines directions for offsets and releases.
- Allows for interpretation of shear force, bending moments, etc.
- Defines Code Check conditions for buckling and deflections.
There are several improvements to the Local Coordinate system including:
- All linear analytical elements can be oriented to the host LCS.
- Loads hosted to analytical elements have consistent LCS notation, which makes the analytical model talk with the analysis packages more consistently. This will also give the structural engineer a better understanding where issues may reside.
- LCS for slabs and floors are well defined, the x-axis is aligned with the span direction of the structural floor.
- LCS for walls is defined; the z normal axis is oriented by the exterior face of the wall family, and the x axis in-plane is oriented upward.
New features in this release of Revit Structure specific to the structural discipline fill in some gaps with reinforcement and analytical model control. These features should help the industry move even closer to a complete solution by allowing the Revit model to link better to fabrication and analysis, improving overall workflow.