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SkyCiv Structural 3D

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Member Designer

Get the most Optimized Sections for your designs, in a single click.

The SkyCiv Member Design Optimizer saves users time, by adding checking every possible section in a given database and choosing the shape with the lowest cross sectional area and best utility ratio. Currently, the Optimizer supports all SkyCiv Design Codes (AISC, NDS, AISI, AS, CSA, BS, Eurocode and more…).

The Optimizer exists on all of our steel, wood and cold formed member design software via SkyCiv Structural 3D, SkyCiv Beam and our Standalone Design software.

Launching the Optimizer

In Structural 3D, there are two ways to launch the Optimizer. Firstly, simply click the Optimize button in the design module of your choice. In the below model, we are using a steel model, that clearly has some failing AISC members:


Second way is to simply highlight which members you wish to design, then right click – Optimize. Note: this will optimize these members’ sections, not each member individually.




Users have a number of controls and settings available, including a targeted Utility Ratio, Section Height/Width limits and which sections you wish to design. By clicking the settings button next to the Optimize button, the following options will appear:



Users have the option to choose between all the sections from the library, a range of section heights or widths. These options will govern what sections, the optimizer looks at when selecting the most optimized section


Users can input their own maximum utility ratio for the optimizer, this would mean that any result with a higher UR than specified will not be considered a valid choice. Users can also specify for the optimizer to minimize the section area as well, it will then find the balance between the highest possible utility ratio and the smallest section area

Member settings

In this area of the settings modal, users can select their design code as they normally would in the Member Design module. Here, they can also choose to optimize their groups or to optimize their sections, within the model.


The results of each section will display in a popup, summarizing the selected section, it’s utility ratio and options on committing. In the below example, all 7 sections of the model. A result was found for all section IDs, except one. The minimum working section for this shape had a Utility Ratio of 1.115:


*The red line indicates that, even the biggest section area could not withstand the loading conditions

We can take a closer look at all the runs and their results by clicking the icon under Iterations. This will display the following detailed list of runs. For instance, selecting section 3 (HSS) will show the following:


From here we can sort by Max UR, cross area and SFO (a weighted index) which will show the best result based on your predetermined criteria (in settings). This allows users to review the optimization runs to make sure the right section has been selected. In the above example, we set a max Utility Ratio of 0.95 and a desire to minimize the cross section area.

SFO for each result is calculated as shown below.

Committing your Results

Once you’re happy with the results, you can hit Back and click Commit Changes to accept those sections. The software will commit these shapes in both the Design module, and your Structural Model. The software will also re-run your design check to give you the most up to date results. So in our above example, after committing we can see the sections are all working (except for the one section which was over loaded):


Changing your section from the design mode, will mean that your analysis results are out of alignment with your current model. For this reason, we highly recommend going back and resolving your model and re running the design check to ensure your analysis and design results are in sync.


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