HyperFEA is the tool that drives automated FEA iteration for load path convergence and global optimization.
After Sizing, panel and beam Zones will have updated dimensions and material properties. These updated properties will impact the overall stiffness of the global FEM which, in turn, will modify the global load path. This necessitates iteration between HyperX and FEA in order to ensure the sizing remains accurate for the updated loads, and converge on a global load path. To lay out more clearly, a typical design sizing workflow proceeds as follows:
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Size the Project: Perform initial sizing based on current loads
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Update and Submit the FEM: HyperX generates an updated FEM (model_i.bdf) with new property and material entries and submits it to the FEA solver
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Import Updated Loads: The new element forces, representing the updated load path, are imported back into HyperX
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Re-size and Repeat: The project is re-sized based on these new loads, and the cycle repeats until the loads and global mass converge
HyperFEA streamlines this by automatically submitting, monitoring, and iterating FEA solutions—including linear static, nonlinear, or eigenvalue solutions—until load path convergence is achieved.
Prerequisites
To run HyperFEA, all Zones in a project must be properly set up for Sizing. This means that each Zone:
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Has been organized into a Structure.
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Has been assigned a Design Property with all Sizing inputs fully defined.
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Has desired failure criteria activated in an assigned Analysis Property.
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Has been assigned a FEA Load Extraction Technique via Load Property.
Note
As of version 2025.1.4, HyperFEA can be run when some Zones are not completely set up. Those Zones will not be used by HyperFEA and warnings will be printed to the HyperFEA output console.
Incorporating Global FEA Constraints in to your HyperFEA iterations requires:
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Relevant FEM/Results Files must be added to the Project. For example, if implementing a Global Buckling Constraint, ensure that buckling load case(s) and corresponding results have been included.
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Manual FEA Constraints require displacements in the FEA results files for the Design Load Case of interest. Automated FEA Constraints require displacements AND element forces in the FEA results for the Design Load Case of interest.
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Stiffness Requirement Failure Mode must be added to the Analysis Property of any Zone that could be sized by the constraint.
This is the mechanism by which the local, Zone-level stiffness requirements are able to drive Sizing. See Stiffness Requirement Methods for more information on how the margin check(s) work.
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Set(s) should be created to collect any Zone that you would like the constraint to apply to. If a Set is provided, HyperX will only "look at" those Zones when enforcing Stiffness Requirements. For example, to drive out buckling modes by only sizing the stiffeners (not the skins) of a panel, create a Set of the bar elements in the panel.
Note
This step is required by the Manual Constraint approach. It is optional if using Automated Constraints.
There are additional setup steps required depending on the type of problem (displacement/rotation, buckling, frequency, or static moment) and the type of constraint (automated vs manual). This information can be found on either the Automated or Manual constraint page for each problem type.
Step #1: Open HyperFEA
The HyperFEA window is launched from the Run tab of the Ribbon:
Clicking this button results in a 'blank' HyperFEA window:
See HyperFEA Ribbon, Explained for an overview of each button seen on the screen, independent of steps in the workflow.
Step #2: Set Up FEA Solver Paths
Tip
If this is your first time running HyperFEA, be sure to complete this process. Otherwise, you can proceed to the next step.
HyperX needs to know where the FEA solver executable is located so that it can submit the iteration FEM for analysis. It will attempt to autodetect the solver path based on the solver type identified during FEM Import, but it is worth performing these steps to double-check.
Note
This is the "standard" HyperFEA setup, as of version 2025.1.4, you can run HyperFEA via Batch File which has a slightly different setup process.
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In the main toolbar, click Tools | Options.
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Select your solver from the drop-down menu.
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Browse to the path of your solver executable.
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Click Test Solver Execution. - If the test fails, check that your path looks similar to the solver paths listed below.
Once this test is passed, you can proceed to the next step.
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Click OK.
Step #3: Set Iterations or Convergence
Next, define when HyperFEA is to stop running. Historically, this is given by a user-input number of iterations - in which an iteration consists of one sizing, FEA solve, corresponding force reimport, and resize. Defining a set number of iterations is done using the first option on the ribbon.
Instead, as of HyperX version 2026.1.13, Convergence Criteria can be used to create custom conditions that automatically stop HyperFEA iterations once they are met. The conditions can pertain to the convergence of weight, stiffness, and FEA constraints (such as displacement and buckling) and can be combined into user-defined logic statements. Defining Convergence Criteria is done using the second button on the ribbon.
For more information, Convergence Criteria for HyperFEA.
One or the other must be defined in order to run HyperFEA.
Step #5: Click "Run"
Selecting "Start" will reveal a few options: "Start with Sizing" or "Start with FEA". As of version 2025.1.4, there is a third option: "Update FEM and Analyze".
If the Project has not already been Sized (i.e. does not have updated dimensions to write to an iteration FEM), select "Start with Sizing." Conversely, if the Project has already been Sized to the initial loads, there is no need to repeat that step - therefore, "Start with FEA" is the appropriate choice. "Update FEM and Analyze" will run one iteration as if you chose "Start with FEA" with "Finish with Analysis" enabled. Selecting one of these options officially starts the iteration process.
The resulting iteration loop that occurs is summarized below.
Iteration Loop - For each iteration...
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Size the Project (Skipped on first iteration if "Start with FEA" is selected).
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HyperX automatically updates the FEM input file with latest sizing results
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Updated FEM is automatically submitted to the FEA Solver
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Automatically import new FEA forces
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Optional - Global FEA Constraints
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Compute Constraint values (grid deflections, eigenvalues, and/or static moment)
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Set Zone required stiffnesses accordingly
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Run Sizing in HyperX
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If Convergence Criteria are applied, they are evaluated to determine if another iteration is needed.
If "Finish with Analysis" is "on"
Two additional steps occur per iteration if this flag is turned on (as of 2026.1, it is "on" by default):
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Copy all sizing results to Analysis Overrides
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Project is Analyzed
Tip
This setting allows you to see a margin assessment for the exact sizing results captured in the current FEM input file.
Step #6: Monitor Iteration Progress
Throughout each iteration, the global weight and Iteration Report can be monitored to ensure the solution is proceeding as intended.
Iterations can be terminated at any point using the 'Stop' button. To restart from scratch, click the Reset button. This will clear the iteration history and set the Run Deck results file back to the source file. HyperX Sizing results are not modified.
Tip
A Stress Report can also be generated for each iteration on request. Configure this option in the HyperFEA Settings window.
More on the Iteration Report...
During each iteration, reports are generated containing detailed information about the Sizing results and (if applicable) the global FEA Constraints. To view the report, click the "Details" icon or right-click a row in the iteration list.
The report contains two tabs: Constraints and Sizing. If there are no Constraints, only the Sizing tab will be shown. The Constraints tab is listed first in the report since the Constraints are computed before the Project is Sized.
Tip
Use the "Export to Excel" feature to copy all the FEA Constraints and Sizing data for all iterations to an Excel spreadsheet.
Constraint Report
The Constraint Report is shown below. The first section shows the details of each active Constraint. In this case, the maximum grid deflection value is shown for each Constraint. The factors from each Constraint are used to apply the required stiffness values to the Zones listed below.
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Factor = Value / Limit
The second section shows the Zone stiffness details. The mass and centroid of each Zone are listed since this information is required for Static Moment Constraints. The Zone stiffness values are listed next. In this case, only the \(D_{11}\) stiffness values are shown since only the \(D_{11}\) stiffness is being modified by the Constraints.
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\(D_{11}\)= current stiffness
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\(D_{11,req}\)= current required stiffness
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\(D_{11, req*}\)= next required stiffness = \(D_{11}\) x Factor
Beyond converging internal loads, HyperFEA is used to enforce and satisfy global model constraints that individual Zone sizing cannot address alone. During iteration, limits can be placed on nodal deflection, buckling, natural frequency, and static moment in the form of Global FEA Constraints.
FEA Constraints work by translating global phenomena in to local, Zone-level Stiffness Requirements.
Using the wind blade below as an example: a global tip deflection target has been translated into local, Zone-level stiffness requirements along the spar cap - as illustrated by opening each Zone's Panel Settings form. These stiffness requirements become Failure Criteria that the sizing of each Zone must meet in order to have positive margins of safety.
HyperX provides two approaches for enforcing FEA Constraints: Automated and Manual.
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Automated Constraints - Here, HyperX automatically identifies the most efficient stiffness path and corresponding Zones to adjust based on the strain energy distribution, calculated from element forces. This is the recommended approach, especially for more complex models, because it finds the optimum stiffness distribution with minimal user setup and tuning.
Tip
This algorithm underwent extensive updates prior to the release of version 2026.1, particularly to address Global Buckling Eigenvalue Requirements. It is now the recommended approach for enforcing FEA Constraints in HyperX.
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Manual Constraints - In this approach, the user explicitly defines which Zones and specific stiffness terms (e.g., membrane vs. bending) to adjust to address a given constraint. This is the legacy approach to enforcing FEA Constraints. While typically more stable and faster to converge, this approach requires significant user expertise for setup and tuning to achieve a mass-efficient solution.