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Spring
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The ``Spring`` element models axial spring behavior between nodes and can be
used to add elastic supports or connections in structural models.

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Overview
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Element type: ``Spring``

Supports:
- Axial spring stiffness
- Used alongside truss elements in Riks-type analyses

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Parameters
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Mandatory Parameters
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   * - Parameter
     - Description
   * - ``type``
     - Must be set to ``"Spring"``
   * - ``material``
     - Spring stiffness and properties (depending on input format).

Optional Parameters
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   * - Parameter
     - Description
   * - ``direction``
     - Optional directional definition if applicable.

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Examples
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Representative example using ``Spring``:
- ``examples/ch04/ShallowtrussRiks.pro``