> ## Documentation Index
> Fetch the complete documentation index at: https://docs.ntop.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Natural Frequency Constraint

Define a natural frequency constraint for optimization to generate shapes with natural frequencies that lie inside or outside the specified range.

### Inputs

| Name | Type | Description |
| - | - | - |
| Number of modes | [Integer](../../../../block-documentation/types/integer) | Number of modes that will be searched for and included in the constraint computation. |
| Band type | Inside or Outside Enum | This defines whether the natural frequency of the optimized shape lies inside or outside the range defined by the Min Frequency and Max Frequency inputs. |
| Min frequency | [Scalar](../../../../block-documentation/types/scalar) | The lower bound of the natural frequency range. |
| Max frequency | [Scalar](../../../../block-documentation/types/scalar) | The upper bound of the natural frequency range. |
| Load case | [Boundary Condition List](../../../../block-documentation/types/boundary-condition) | Load case for the constraint. |

### Outputs

| Type |
| - |
| [Design Constraint](../../../../block-documentation/types/design-constraint) |


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