Computer Aided Engineering Design

SOLID MODELING 273

positions between the shank and head, and shank and threads should not change, i.e., the three
features should remain glued appropriately along the common geometric axis. Parametric design of
CAD models, being a noteworthy concept, has and is receiving considerable attention of commercial
solid modelers.

Exercises

1.Verify the Euler characteristic for the following polyhedrons:
A block with a through block void
A tetrahedron
An open cylinder
A torus
2.Construct the edge and vertex tables for a cube as a wireframe.
3.Construct the winged edge data structure for a cube as a B-rep solid.
4.From a cube, construct a tetrahedron using Euler operators.
5.A Mechanical component made by assembly of three parts is shown in the Figure P8.1 along with dimensions.
A CSG Representation is to be made. Define the minimum basic primitives to be used for constructing the
component. Give Details of the CSG tree for the given component. Include details of primitives, transformation
involved (scaling translation, rotation) and the Boolean operations. Model the components shown in Figure
P8.1 using any of the available solid modelers.

133

3

R38

28

54

54

58

32

38

54

54

12

130

12

32

28

108

32

58

50

φ 5

82

57

50

88

Figure P8.1 A Mechanical component.