This tutorial uses the Keyword file meshtosurface.k. In the pulldown menu, go to File > Open > LS-DYNA Keyword File, choose meshtosurface.k. You will see the following mesh model displayed in LSPrePost mainpage.

Figure 6.1: A Mesh Model

Click the menu button Geometry > Surface > Fit from Points/mesh. Both Fit surface from Points/Mesh dialog and Mesh Selection dialog are shown.

Figure 6.2: Dialog for Selecting Mesh

Select Mesh Option. Select the ByPart radio button in the Selection panel.

Figure 6.3: Mesh Option

Click Preview. An initial surface is generated. The right picture shows the initial surface, and the left picture shows the details at the corner position.

Figure 6.4: Preview Surface

A message is printed in the bottom dialog: Control point #:u=21 v=31; max dev:0.439477,mean dev:0.104203. This message reports that the initial surface has 21 control points in U-direction and 31 control points in V-direction, the maximum deviation between surface and mesh nodes is 0.439477, the mean deviation is 0.104203. The maximum deviation is under the default threshold setting 0.5 .

Figure 6.5: Tolerance

Set the parameter Max Tol to 0.3. Click the Fit button. The surface is updated. The message reports 'Control point #:u=27 v=38; max dev:0.256196,mean dev:0.054895.

Set the parameter Max Tol to 0.1. Click the Fit button again. The surface is updated. The message reports 'Control point #:u=33 v=43; max dev:0.093604,mean dev:0.016271'. You will see the updated surface is very near to the corner point position from the following picture.

Figure 6.6: Improved Surface

Set the parameter Max Tol to 0.05. Click the Fit button again. The surface is updated. The message reports 'Control point #:u=40 v=48; max dev:0.049742,mean dev:0.009516'.

When you decrease the max tolerence threshold, the surface control point number will increase in both of U-direction and V-direction in order to get more details for higher precision.

When you get the satisfactory surface, click Apply to add the surface into database.