engineering

Chapter # 3

1. Geometry provide the building blocks for the engineering design process.

2. Engineering geometry has to be referenced to coordinate system in order to both define its from and relate to other geometry

3. The right-hand rule is used to determine the positive direction of the axes. To visualize the right-hand rule, make a fist with the right hand, with the thumb pointing outward. The direction the thumb is pointing indicates the positive direction on the X axis. Straighten the index finger so that it is pointing straight up, at 90 degrees to the thumb. The direction the index finger is pointing indicates the positive direction on the Y axis. Straighten the middle finger so that it is pointing forward, at 90 degrees to the index. The direction the middle finger is pointing indicates the positive direction of the Z axis.

4. A straight line is generated by a point moving in a constant direction.A curved line is generated by a point moving in a constantly changing direction.

5. Parabolas and hyperbolas are used to focus electromagnetic radiation.

6. A surface is a finite portion of a plane

7. Square, rectangle, rhombus, trapezoid, trapezium

8. Circles of unequal radii which share the same center point

9. A line which touches a circle at one and only one point

10. used in the design of arched ceilings .

Chapter # 4

1. manifold object unambiguously divide a region into and outside. Non manifold objects don't do this

2. CSG models use solid primitives and half spaces related by Boolean operation in a binary tree date structure. B-rep models define a solid region by surfaces, edges, and vertices. Wireframe models don't define a volume, but describe just the edges and vertices of a 3-D model

3. The three types of Boolean operations are Union, difference, and intersection. Yes, the same final object can be derived using Boolean operation in a different order.

4. Changes in geometry of a feature should create model feedback or further changes in the model that reflects design performance or Manufacturing constrains of the product.

5. With unidirectional associativity, the supporting application date can be altered by changing the 3-D model, but not vice versa. With bidirectional associativity, changes in either the 3-D model or the date in the supporting application will affect the other

6. In sweeping operation, a closed polygon, called a profile, is drawn on a plane and is moved or swept along a defined path for a defined length. Linear, revolved, path based, and blend

7. Sketch planes are elements of construction geometry used in a 3-D CAD program to establish the position and orientation of a feature. Five ways to define a sketch plane include: (1) with respect to the default X-Y, Y-Z, or Z-X datum planes, (2) on the surface of an existing feature, (3) parallel to and offset from an existing feature or sketch plane, (4) at an angle to an existing surface and edge, and (5) tangent to a surface.

8. A child feature is defined relative to a parent feature through geometric definitions such as constrains, alignment, or work planes. Child features exist below their parent features on a feature tree

9. Linear and radial arrays. Linear arrays need the number of copies to be made in each of two orthogonal dimensions and the offset in each of these dimensions. Radial arrays need a rotation axis, radial distance from the axis, number of copies, and the angular offset. pp. 178-179

10. Model ( object), viewer ( camera ) and projection ( view) plane. Panning and zooming don't change the projection in parallel projection

11. Child views are projected relative to the base view. For example, a front view could be defined as the base view and the top and side views created by rotating the viewpoint relative to the front view.

12. Visual, kinematics, mass properties and ergonomics are some examples. They don't all have to be use all of the time

13. 1virtual testing of manufacturing processes cuts down on material waste, reduces troubleshooting time and frees up production equipment