If you’ve ever wondered why there are so many joint types available when using the ‘Create Joint by Model’ function in Consteel, and when each type should be used, this article provides clear explanations directly from the developers.
Introduction
The process starts by selecting intersecting members using the ‘Create Joint by Model’ option under the Structural Members tab. It’s important that at least two members intersect so that a connection can be defined. Once selected, a window appears with a list of available joint types on the right. The list is dynamic and depends on the selected members. For instance, if the joint does not meet Eurocode standards, Consteel Joint connection types will not be displayed.
Consteel Joint
Consteel Joints are ideal for standard, Eurocode-compliant connection designs. When using the same ‘Create Joint by Model’ feature, depending on the selected elements, users may see multiple Consteel joint types. These can include connections like beam-to-beam joints with or without a main element, bracing connections that require the user to select the primary structural element, or column base joints, which can also be accessed via the spread footing tool.
Fictive Joint
The Fictive Joint is particularly useful in collaborative design workflows where multiple teams or companies contribute to the structural design or when engineers decide to design the connections in their traditional way, using, for instance, handmade Excel spreadsheets. In such cases, specific joints may be designed externally, but all the necessary data is collected from the Consteel model and can be exported to a .csv file, Excel-compatibile format. This typically includes information such as placement, member names, local coordinate directions from J to K, internal forces and moments according to all analyzed load combinations.
Using Fictive Joint, users can easily place the required joints in the model, categorize them according to type, and export all necessary data into a .csv file, Excel-compatibile format. It is important to note that data can only be collected after the Fictive Joints have been placed and the analysis has been run.
The Fictive Joint collects internal forces from each position where it is placed, streamlining communication with external design teams. If the structure is modified, it updates automatically after reanalysis, saving time and avoiding redundant work.
Make sure to export the .csv file after the final changes have been made.
Why choose Consteel Joint?
One of the biggest advantages of Consteel Joint is its full integration within the software. There’s no need to install additional plugins or manage separate licenses. The tool automatically uses all the modeled data—such as geometry and applied loads—making the process straightforward and efficient, accounting for all internal forces directly from the model, where it is placed. Another key benefit is that when joints are designed and placed directly in the model, their stiffness can be included in the overall 3D structural analysis. This results in more accurate and realistic calculations.
When to use Fictive Joints instead?
However, it’s important to note that Consteel Joints are only applicable for standard connection types. For special joints, where Consteel cannot perform the design, the Fictive Joint offers a flexible and practical solution for identifying, organizing, and sharing the necessary information with others.
Conclusion
In summary, Consteel Joints offers a powerful, integrated solution for standard connection design, while Fictive Joint is an essential tool for managing custom or externally designed connections. Understanding the purpose and capabilities of each will help you streamline your workflow and collaborate more effectively within complex design projects.
Did you know that you could use Consteel to calculate rotational stiffness for bolted column/beam moment bearing connections?
Download the example model and try it!
Download modelIf you haven’t tried Consteel yet, request a trial for free!
Try Consteel for freeBolted connection
Bolted connection
Welded connection
Did you know that you could use Consteel to consider connection stiffness for global analysis?
Download the example model and try it!
Download modelIf you haven’t tried Consteel yet, request a trial for free!
Try Consteel for freeAssumed rigid connection without considering connection’s actual rigidity
Considering connection’s actual rigidity 52% increase of deflection!
Considering connection’s actual rigidity 33% increase of deflection!
Consteel 14 is a powerful analysis and design software for structural engineers. Watch our video how to get started with Consteel.
Contents
- Build joint model based on the global model
- Bolted moment end-plate connection design
- Base plate connection design
- Apply connection stiffness in analysis
Read our tips and tricks about Choosing the orientation of a symmetric joint for more information.
Version: CS14.1000
Click the button below to download the model.
gateIntroduction
The effects of the behaviour of the joints on the distribution of internal forces and moments within a structure, and on the overall deformations of the structure, should generally be taken into account, but where these effects are sufficiently small they may be neglected.
Classification
In the case of elastic analysis, joints should be classified according to their rotational stiffness. The joints should have sufficient strength to transmit the forces and moments acting at the joints resulting from the analysis. A joint may be classified as rigid, pinned or semi-rigid, according to its rotational stiffness, by comparing its initial rotational stiffness Sj,ini with the classification boundaries given in EN1993-1-8 5.2.2.5. In the case of a semi-rigid joint, the rotational stiffness Sj corresponding to the bending moment MEd should generally be used in the analysis.
Calculation of joint stiffness
Consteel Joint calculates the Sj,ini initial stiffness of the joint, the Sj,sec secant stiffness for the actual loading and determines the classes of stiffness and strength (last one for plastic analysis).
Sj,sec is equal to Sj,ini when MEd does not exceed 2/3*MjRd (EC3-1-8 5.1.2. (3) ), otherwise it is calculated.
Automatic consideration of connection stiffness
gateIntroduction
Joint orientaion can be chosen by the graphical display of the Place joint on the model function.
How it works
If there is only one option how to place a joint e.g. a single beam connected to a column, the orientation of the joint on the graphical display has no effect on the orientation of the placed joint.
IF:
- There is more than one option on the placement and
- The geometry of the connected members are completely the same
the orientation of the joint on the graphical display will determine the orientaion of the placed joint.
Please see below an example for two different orientations of the same joint. In the first row of pictures the joint is placed in a way that the longer connection plate with the bolts outside the beam flanges is on the right side (‘Right flange’ on the picture). You can see in Consteel Joint that the higher (152 kNm) moment acts on the right side.
In the second row, the same joint is placed with opposite orientation – the long connection plate on the left side. It is visible that the 152 kNm is now on the other side (the one with the shorter plate and bolts inside the flanges).
gateIntroduction
When you create a new joint either manually or by model, certain parameters are set to a default value e.g. weld sizes, method of weld design, bolt material and diameters, stiffener plate properties etc…
When you’re working on a large model, or simply want to design more joints in Consteel Joint, setting these default parameters one by one (e.g. if you have a specified palette of bolts or plate material) at each joints would take a lot of time. In this case, creating a new, user defined default setting can be very helpful, and can save you time.
How it works
The default joint settings can be modified at the Default joint settings dialog. It can be opened either when creating a new joint (manually or by model) or from Joints dialog.
