Just a quick post to let you know that I will be presenting a webinar session this Friday (28th September @ 10am). You will see some interesting AEC Collection workflows for the following topics:
Join us with the link below.
The Recording can be found here:
Once on the page click the link marked in red and fill in the form.
Here are some images of the workflows we will be using on Friday!
Hope to see you!
LawrenceH
In part 1 of this tutorial we looked at the creation of vertical bracing systems using Revit 2019, in this part we will focus on roof bracing systems in Revit 2019.
Roof bracing tends to get a little more complex than vertical bracing due to compound angles and complex connection configurations. Revit has some good tools to make the placement of roof bracing easier. We will also cover some tips and tricks for the representation of bracing in plan.
As mentioned in the part 1 of the tutorial, you should always use the dedicated brace tool rather than the beam command as shown below.
It is easier to add the roof bracing in a 3D view. It is very important to ensure that you have the 3D snapping option checked on the options bar as indicated below.
You can then roughly sketch your bracing configuration by snapping to the top of each rafter as shown below. Don’t worry about getting the exact position, this will be set in a later step. Do not snap to the column.
The bracing will automatically be placed on the centre line of the rafter, but the analytical model will automatically adjust to the top of steel.
When a brace is selected you have the option of setting the location via a ratio or a distance along the beam. The example below shows the start of the brace set 300mm from the column and the end of the brace set to 5000mm. The plan shows the position of the brace.
Another method of placing the bracing is to use a ratio. The ratio at the start of the beam is 0 and the end of the beam is 1. In the example below a brace is placed 30mm from the start of the first rafter and then at a ratio of 0.25 (25%) along the second rafter. This value will remain parametric if the length of the rafter changes.
PLAN REPRESENTATION OF BRACING
In part 1 of the tutorial you will have seen that plan bracing is represented in a course level of detail with an offset dashed line. This is perfect for vertical bracing but not so good for roof bracing! In the image below, you can see the offset showing in the plan.
This is due to the plan representation showing a parallel line and offset. However, we will use the Kicker brace symbol to represent the bracing in plan.
To set the bracing to kicker bracing, in the Properties Palette, set the structural Usage to Kicker Bracing as shown below.
You can of course edit the line pattern and the symbol for kicker bracing.
In the example shown below I simply edited the line pattern in the object styles for kicker bracing and deleted the X in the M_Connection-Brace-Kicker.rfa.
ADDING STRUCTURAL CONNECTIONS IN REVIT 2019
You can of course add some basic connections in Revit 2019, but you must make sure that you create the bracing first and then add the relevant connections. If you add connections before the steel model is complete you will not be able to 3D snap to the rafter.
The below image shows the Double Tube Bracing connection dialog box. The 3D representation of the connection is almost identical to the advance steel connection. However, of you require fabrication documents, accurate cutting lists, constructability verification and CNC code then Advance Steel can be used.
Advance Steel can create full fabrication documents and details. The image below shows the same frame in Advance Steel. This has been transferred using the Advance Steel extension which will keep both models synchronised.
In the images below you can see assembly drawings that are automatically created for the rafters and haunches.
Here is a list of plates and surface areas for galvanising.
Finally the CNC data is generated for the automated drilling and cutting of each item in the model.
LawrenceH
I still find many people asking what the best methods are for adding bracing to steel models, some are still using beams to try and model bracing, others still get into a bit of a mess with vertical bracing, more struggle with the representation on drawings.
I thought it was about time I created a tutorial on this subject, covering both horizontal and vertical bracing as well as some typical connections for adding those all-important details.
So first we need to look at some of the basics. In the images below, you can see Vertical, Horizontal and Roof Bracing.
Creating Vertical Bracing
When creating vertical bracing it is best to create a framing elevation. The framing elevation creates an elevation on the frame a few hundred millimetres deep and sets a working plane for the bracing.
You must use the dedicated brace command to efficiently add bracing.
You can roughly sketch the bracing that you require and then use the Properties Palette to fine tune the exact location of the bracing.
In the example below, you can see some vertical X-bracing, note that the start and end attachments are attached to the correct levels and you also have the option of adding offsets from each of these levels.
In this example we have used Equal Angle to create the bracing. Both angles are in the same plane and hence clash.
This can easily be resolved by using the y Offset Value on each member. The analytical line remains centred, but the physical elements will be located correctly.
The bracing is automatically represented in a plan view and can be tagged. The standard in the UK is to show a parallel line on the outside for bracing above and a parallel line on the inside for bracing below.
You can control the type of representation and spacing in the Structural Settings dialog box.
Finally, if you want to tidy up the bracing and make the drawings look a little better you can either use 2D detail components to represent a connection or use the connection tools to add 3D connections.
LawrenceH
Many of you may already know that if you would like to design a pile cap for punching shear with Robot you need to manually model the pile cap as a panel and then manually set up all the piles and the footprint of the column. This can be a real pain when the geometry changes!
A better approach is to unleash the power of Dynamo to help model the analytical panels and nodes that can be used by Robot Structural Analysis. You will first need to make sure that the package ‘Structural Analysis for Dynamo’ has been installed.
You will then see a range of nodes that allow you to take Revit geometry into Dynamo and then create Autodesk Robot Structural Analysis elements. The main idea behind the process is to take the top surfaces of the pile caps and then build panels from these in Robot. We then take the footprint of the column and the pile diameters and model these as panel openings. In the example I have used you can see the Revit model and the panels and nodes that are created in Robot.
If there is enough interest I may create a full tutorial video for this process but if you can’t wait to test this out then you can download a large image of the Dynamo graph from here:
LawrenceH
In this short tutorial we will look at the reinforcement of a simple column and foundation. The reinforcement is modelled manually to show you how reinforcement bar is placed in elements. We then schedule the reinforcement to BS8666:2005 and produce a simple drawing.
Here is the bending schedule shown below.
The tutorial is using the Excitech Revit RC template but everything else is standard Revit 2019.
Hope you enjoy the tutorial?
LawrenceH
Well, it’s that time of year again to review the new features of Revit, seems to come round so fast. As I did last year, I will review the steel and concrete features as separate blog posts and videos as we have a raft of new features to look at!
If you would like to jump directly to the steel video then here is the link.
New Steel Ribbon
Autodesk are further extending the Level of detail that can be presented by adding specific modelling tools to extend the power of structural connections and end treatments. You now have dedicated tools to create notches, saw cuts, holes and chamfers and rounds to steelwork. This allows for a greater Level of Detail when modelling and these features can be directly linked to Advance Steel for full Automatic fabrication documents.
The use of these new tools will depend on the need for modelling to this level of detail. For example, bridges may require a greater Level of detail but a traditional steel frame modelled by an engineering consultant may not require any connection details, these will be added by the fabricator.
A particularly nice feature is the ability to use a standard connection and then break the connection into the fabrication elements such as plates, bolts, cuts etc. This allows for easy modifications to connections and the ability to create your own connections.
For a detailed look at each tool check out my video at the top of this post.
Enjoy,
LawrenceH
Some years back in 2015 I reviewed the Technology Preview of Autodesk’s new structural analysis package, React Structures, a fresh-looking ‘brother’ of Robot Structural Analysis with better integration with Revit and Dynamo. The main advantage was a cleaner, easier to use interface along with simpler workflows.
Autodesk React Structures was in Technology Preview for many years and recently seemed to be retired, so what could have happened?
Before I speculate on possible futures, perhaps we can take look at some recent trends in the construction industry and the use of design software.
The last three to four years has seen a quantum leap in the use of BIM models to communicate design ideas, transfer information, understand risk and manage costs within large projects. In parallel, projects have become more and more complex and clients are demanding better buildings, with reduced fees in less time!
This all adds immense pressure on Structural Engineers to react to design changes and create new designs with maximum efficiency. Many of us will use multiple software products to create design and 3D models and the biggest challenge is the transfer of data without loss and the learning of many complex software tools.
Many of you will already be aware of the cloud based analysis currently in Revit (if not see the previous post). This type of workflow allows data to be seamlessly transferred without conversions or the loss of data and is preferable to the two-way link currently used with Revit and Robot. When Autodesk React Structures was started it seemed a sensible method to take an existing analysis tool and refresh this for the coming years. The rate of progress with BIM processes and software overtook this initial idea which is why Autodesk abandoned React Structures.
I believe the future solutions will be completely integrated and use the same common interface to control the design and analysis models as one, truly unified model. To imagine an early preview of this toolset you could use Revit, Robot Structural Analysis and Dynamo to get a truly ‘live’ environment to develop and analyse structures.
Structural Analysis for Dynamo allows you to access many of the results and data from Robot and store these in the Revit BIM model. For example, you can store the bar number, the Bar Forces and Stresses in each element. You can then use these results to optimise the design within Revit.
In the above image you can see the Structure Analysis for Dynamo package and nodes that are creating loads, running the calculations and then retrieving the results. The image below shows the same space truss with a completely dynamic link from Revit to Robot. Panels have been created in Robot from Revit for the glazing and well as the bars and supports.
The optimisation is the interesting area here, this is where I think Autodesk can really use the power of cloud based computing to rationalise, optimise and design structures more efficiently. Perhaps other FEA tools can be integrated into the database such as NASTRAN for complex shapes.
I am sure we will all keep our eye on any developments from Autodesk in this interesting and exciting area.
LawrenceH
