17 CASE STUDYFIGURE 3,45L!'IGURE3ASFIGURE 47ONCE THE BLADE IS EXTR...

3.17 Case Study

Figure

3,45

l!'igure3AS

FIgure

3.47

Once the blade is extruded, the remaining fillets are added to the part and the

design is complete. The top and bottom isometric views of the completed shovel are

shown in Figures 3.47 and 3.48.

It is important to note that the strength of parametric design is the ability to

rapidly modify steps in the design to improve the final design. The steps that are doc-

umented for this case study are for the final shovel design, but many intermediate

designs were modified to obtain the final one. If something in this design were found

to be inadequate, any of these steps in the design could be reached and modified by

accessing the "history tree" of the part.

For this design, the step of greatest interest was the design of the stiffening ribs.

To help optimize these ribs, the solid model of the shovel head was imported into the

ANSYS finite element analysis software and the loading was simulated under var-

ious conditions. Figure 3.49 shows this simulation for stress under a buckling load.

This load produced the worst results for the shovel but is not expected to be encoun-

tered often, and the addition of the metal blade (which is not modeled in this simu-

lation) will help to relieve some of this stress.

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Product Design, Computer Aided Design (CADl, and Solid Modeling

Chap. 3

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