What is the difference between the Beam Detailing and Sub-frame design links in Sumo?

Sumo’s design links provide two options that export beams to Continuous Beam for design.

  • Beam detailing
  • Sub-frame

Let us look at both and compare the options.

Beam detailing

The Beam detailing design link is intended for concrete beam elements that don’t form part of a larger slab.

It is important to note that in this case, the results that you view in Continuous Beam are directly imported from Sumo. Continuous Beam does not do the calculations when the beam detailing design link is used.


The Sub-frame option exports a Sumo object called a Sub-frame strip to Continuous Beam. The Sub-frame takes the geometry and loading from Sumo and loads it into Continuous Beam. Notice that Continuous Beam does the analysis when this link is used.

This is especially useful when doing a flat slab design. Continuous Beam allows for the consideration of column and middle strips which divide the applied moments proportionally. Another application could be a monolithic T-beam where the flange is the slab, and the web is a rectangular beam.

Using Live Update with a local file repository

Scenario: You want to set up a local repository to use with Live Update. Network permissions may prevent users from connecting to the Prokon web server, or you want to avoid the Internet traffic of many users updating their PROKON installations.

By default, Live Update connects to a Prokon webserver to check for and download module updates. You can change this to have Live Update work with a local file repository.

Step 1: Prepare your local file repository:

  • Perform a full PROKON installation on the network drive, e.g. FileServerRepoProkon
  • Run PROKON and log in to License Manager. This one-time step is required for Live Update to verify your license.
  • Close PROKON.
  • Run the Live Update program, e.g. FileServerRepoProkonBinLiveUpdate.exe, and follow the prompts to download updates.

Repeat step 4 periodically (e.g. weekly or monthly) to keep your local file repository up to date.

Step 2: Configure Live Update to use the local file repository:

For each user, run Live Update, select the option to update from the local network.
Enter the Bin subfolder of the local file repository, e.g. FileServerRepoProkonBin

Optional: Propagate the update source to users’ computers using the values in the Windows Registry key HKEY_CURRENT_USERSoftwareProkonLiveupdateSettings:

DownloadType: DT_LAN
LAN: File repository folder, e.g. FileServerRepoProkonBin

The program does not display on the screen

We have received multiple reports of PROKON modules not displaying on the screen. The program icon would display in the Windows taskbar, but the program itself would not visible.

This behaviour occurs when there has been a significant change in the Windows display settings with regards to the screen configuration. The most common cause is a multi-monitor system where the secondary monitor is no longer present or was moved relative to the primary monitor (e.g. from the right side to the left side of the primary monitor).

Due to the COVID-19 pandemic, this issue has been quite prevalent as many users switched to working from home, with resulting changes in screen configurations.

To fix the display problem:

  • Focus on the PROKON program that does not display. To do this, press ALT+TAB until the PROKON module is selected. (The PROKON module will still not be visible.)
  • Press ALT+SPACE to bring up the display context menu:
  • Maximise the program. The program should now fill your whole screen.
    Use the mouse to grab the program title bar and drag it a bit lower on the screen.

You should now be able to resize the program to your liking.

If these steps do not solve the problem for you, then please reach out to our technical support team for remote assistance.

As of 9 April 2020, newly released versions of PROKON modules will check for this problem situation and re-position programs as needed.

Estimated maximum mesh error

After running an analysis of a model that includes finite elements, the results show that there is an estimated maximum mesh error of 20%. What does this mean?

The mesh stress error indicator output indicates the accuracy of a shell finite element analysis. The program calculates the maximum estimated error by taking the difference in the smoothed and raw stresses anywhere in the model. The program displays the error level across the model as contours, with the 100% level indicating the maximum estimated error level. If the estimated maximum error is 20%, for example, then the 50% contour would suggest an estimated error of 10% (the smoothed stresses differs by 10% from the raw stresses) at the point considered.

Large estimated errors often spell problems but do not necessarily mean that the stress values all across a model are inaccurate or wrong. It does, however, helps you identify zones where refinement of the finite element mesh may improve the analysis accuracy.

Keep the following factors in mind:

  • Error distribution: Peaks in estimated errors only in certain parts of the model suggests that the basic mesh layout is sound. Refinement of the mesh may be needed in the zones where the estimated errors are large.
  • Error location: Small stress differences in critical portions of the model may be significant. Likewise, suppose you are interested in the stresses in a specific part of the model. In that case, large stress difference in remote portions may have a not significant effect in the part considered.
  • Stress smoothing: By smoothing stress, you can improve accuracy in some cases (by balancing out errors). However, it would help if you did not use stress smoothing to try to hide real problems in your model.

In most cases, you can improve the accuracy of the analysis by optimising the finite element mesh, e.g. using smaller elements is zones of stress concentration. When making this decision, you should consider both the local and global characteristics of your model.

Floating and Hosted loads in Sumo

Sumo has two different categories of loads that can be used – Floating Loads and Hosted Loads.

Each of the two categories contains similar loading options (Point Load, Line Load, and Area Loads). An explanation of the two categories is listed below to show the differences.

Floating Loads:

Floating Loads are placed manually and are not linked to any element. When a Floating Load has been defined, the load can be moved, copied, or adjusted like any other element.

These loads are considered independent of other elements in a model.

Hosted Loads:

Hosted Loads are anchored to the structural element on which it was placed. The load can’t be moved from its host. Since a Hosted Load is anchored to a structural element, it also changes as the host element is changed.

Each category of loads is useful for different conditions. Applying a UDL to the entire slab is a good example of where a Hosted Slab Load can be used. If only certain parts of the same slab must be loaded, e.g. pattern loading or checkerboard loading, a Floating Area Load would be more suited. Hosted Loads can be applied to Walls, Slabs, and beams. If a Plane shell is to be loaded, a Floating Area Load must be used.

Taking the next step

We like to make it easy for engineers to get to know and love PROKON 5.2. Download our seven-day free trial and experience how easy it is to utilise all modules without restrictions or obligation to purchase. Purchase PROKON 5.2 online or contact one of our regional partners who can assist you with installation, training and technical support.