Deformable Surfaces

1. From the Model Browser, select the system to which the deformable surface is to be added.
2. Right-click on a system in the Model Browser and select Add > Reference Entity > Deformable Surface from the context menu.
   OR
   Right-click on a curve folder in the Model Browser and select Add Deformable Surface from the context menu.
   OR
   Right-click the Deformable Surfaces button on the Reference toolbar.
   The Add Deformable Surface dialog is displayed.
3. Specify a label and variable name.
   By default, variables names of entities in MotionView follow a certain convention. For example, all deformable surface entities have a variable name starting with “defsur_”. This is the recommended convention to follow when building models in MotionView since it has many advantages in model editing and model manipulation.
4. Optional: Double-click System to change the system, assembly, or analysis the entity will be created in.
5. Click Apply.
6. Click OK.
   The deformable surface is added.

The Deformable Surfaces panel allows you to create a surface that can change shape during the simulation. It can be used to model a PointToDeformableSurfaceJoint MDL entity or a PointToDeformableSurfaceContact MDL entity. The points that are used to describe the surface can belong to one or more bodies (rigid or flexible).

1. If the Deformable Surfaces panel is not currently displayed, select the desired deformable surface by clicking on it in the Model Browser or in the modeling window.
   The Deformable Surfaces panel is automatically displayed.
2. Specify the type of locations to be used to describe the deformable surface by choosing Marker or Body/Point from the Data type drop-down menu.
3. Add, insert, and delete rows and columns.
   Tip:

   • Clicking Delete Row or Delete Column will delete all rows and columns with an activated check box.
   • Clicking Add Row and Add Column will add the number of entities shown in the field.
   • Activating a check box on a row or column then clicking Insert Row or Insert Column will add a row/column directly after the activated entity.
4. Click the Marker, Body, or Point collectors and make your selections in the modeling window, or double-click the collectors and make your selections in the Model Tree
5. Select an end type from the drop-down menu.
   MotionSolve applies a cubic spline interpolation to represent the surface. The spline interpolation requires assumptions on the second derivative at the ends. The end type selected specifies the method of assumption for the second derivative.

   For an interpolating function f(x) with N+1 points:

   Option	Description
   NATURAL	The second derivative at both ends are considered equal [f"(x0) = f”(xN)]
   PARABOLIC	The second derivative at each end is equated to its adjacent point [f”(x0) = f”(x1); f”(xN) = f”(xN-1)]
   PERIODIC	The second derivative is periodic at the ends and can be used for periodic surfaces [f”(x0) = f”(xN-1); f”(x1) = f”(xN)