Learn to create and assign Load Properties as you size a wing. Try a few different Load Properties, each corresponding to a different FEA Load Extraction method, to compare their effect on Sizing results and processing times.
Show Only the Upper Skin Structure and Review Existing Setup
Selecting the Upper Skin reveals:
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Simple Plate Design Property assigned.
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Metal Plate – strength Analysis Property assigned.
Tip
Double-click on each Property to understand the problem definition.
Create and Define an 'Element Based' Load Property
To create a Load Property from the Ribbon:
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Navigate to the Model tab
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Select ‘Load Extraction Method’
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Select ‘Element Based’
To create a Load Property from the Property Tree:
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Right-Click on the ‘Loads – FEA’ node.
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Select ‘Create Element Based’.
Creating a Load Property launches the following window:
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Name the Load Property.
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Select which element load components you’d like to include in processing.
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Click ‘Apply’ to save.
Run Sizing and Assess Results
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Select upper skin and run Sizing. Document about how long the sizing takes.
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Open Legend to view results.
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Show minimum margin of safety per element.
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Show minimum margin of safety per Zone.
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Record weight from Structures Tree
Create Average Load Property, Assign, and Re-run
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Create a new Average Load Property. Include all load components in the definition and select "Tension/Compression" on the form.
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Assign the new Average Property to the upper skin.
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Re-run Sizing
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Document relative Sizing time.
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Record minimum margin of safety value.
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Record Structure weight.
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Run Element-based Analysis of Average Sizing Results
Better understand the consequences of average-load sizing by assessing the element-by-element margins of the results.
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Select the Upper Skin.
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Assign the existing Element-Based Load Property to the selected Zones.
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Click ‘Results to Overrides’.
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Click ‘Analyze’.
Open Legend to view results and compare to average margin results.
Note
Average solution is lighter because high loads are weight-area-averaged with their low counterparts, so negative individual element margins persist.
Repeat Element-based Comparison for 2-Sigma Load Property
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Open Simple Plate Design Property and switch to Detailed Sizing mode
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Create a 2-sigma Load Property
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Assign 2-sigma Load Property to the upper skin and re-Size.
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Document relative Sizing time.
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Record minimum margin of safety.
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Record Structure weight.
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Run Analysis and review results. Compare to previous 2-sigma results.
Note
2-sigma solution is lighter because high loads are statistically processed with their low counterparts, so a small amount of negative individual element margins persist.
Peak-Element load processing leads to the same results as element-based sizing, in ~1/10th of the time.
Statistical processing metrics are quick, and lead to lighter solutions, but negative margins can still persist at the element-level.
Note
The time difference between statistical methods and peak element increases as the number of load cases increases