MAE 455 COMPUTER-AIDED DESIGN AND DRAFTING MIDTERM EXAM PRACTICE QUESTIONS. Name: You are allowed one sheet of notes.

Transcription

1 47 MAE 455 COMPUTER-AIDED DESIGN AND DRAFTING MIDTERM EXAM PRACTICE QUESTIONS Name: You are allowed one sheet of notes. 1. What constraints could be added to fully constrain the wireframe shown? Include constraints to remove rigid body motion. Do not over-constrain. Vertices: A, B, C, D, E, F, G Straight Lines: AB, BC, DE, EF, FA Circular Arc: CD (with center G) Draw constraints here. Write out constraints here. F E D G C Ref. Line 2 A Ref. Point B Ref. Line 1 1

2 2. Sketch the figure resulting when the following constraints are satisfied for the following entities. Entities Vertices: A, B, C, D, E, F, G, H Straight Lines: AB, BC, DE, EF, FG, GA Circular Arc: CD (with center H) Constraints Coincident (G, Ref1) Vertical (GA) Perpendicular (FG, GA) Distance (FG, AB, 2 units) (AB below FG) Distance (GA, BC, 3 units) (BC right of GA) Distance (BC, EF, 2 units) (BC right of EF) Distance (AB, DE, 5 units) (DE above AB) Radius (CD, 1 unit) Tangent (BC, CD) (H left of BC) Tangent (CD, DE) (H below DE) (BC smooth tangent with CD) (CD smooth tangent with DE) Ref1 2

3 3. What constraints could be added to fully constrain the wireframe shown? Include constraints to remove rigid body motion. Do not over-constrain. Vertices: A, B, C, D, E, F, G, H Straight Lines: AB, CD, DE, EF Circular Arcs: BC (with center G), FA (with center H) 10 Draw constraints here. Write out constraints here. E D F A G, H C B Ref. Point Ref. Line 2 Ref. Line 1 3

4 4. Sketch the figure resulting when the following constraints are satisfied for the following entities. Entities Vertices: A, B, C, D, E, F, G, H Straight Lines: AB, CD, DE, EF, FG, GA Circular Arc: BC (with center H) 10 Constraints Coincident (A, Ref1) Horizontal (EF) Perpendicular (EF, FG) Distance (EF, CD, 1 unit) (CD above EF) Distance (EF, GA, 2 units) (GA above EF) Distance (FG, AB, 1 unit) (AB right of FG) Distance (FG, DE, 2 units) (DE right of FG) Radius (BC, 2 units) Tangent (AB, BC) (H right of AB) Tangent (BC, CD) (H above CD) (AB smooth tangent with BC) (BC smooth tangent with CD) Ref1 4

5 5. Sketch the figure resulting when the following constraints are satisfied for the following entities. Entities Vertices: A, B, C, D, E Straight Lines: AB, BC, DE, EA Circular Arc: CD Constraints Incident (A, Ref1) Incident (A, Ref2) Angle (AB, Ref2, 45 ) B above Ref2 Mirror (AB, EA, about Ref1) Distance (E, B, 5) (B right of A) Angle (AB, BC, 22.5 ) C above AB Mirror (BC, DE, about Ref1) Radius (CD, 1) Tangent (BC, CD) (D above BC) Tangent (CD, DE) (C above DE) Ref1 10 Ref2 5

6 6. List a sequence of solid modeling operations that can be used to create the shaft shown. Include all reference geometry and sketches. Show intermediate solid shapes. Dimensions and constraints do not need to be shown. Good modeling practice must be followed. 6

7 7. List a sequence of solid modeling operations that can be used to create the wire bookend shown. Include all reference geometry and sketches. Show intermediate solid shapes. Dimensions and constraints do not need to be shown. Good modeling practice must be followed. 15 7

8 8. List a sequence of solid modeling operations that can be used to create the tray shown. Include all reference geometry and sketches. Show intermediate solid shapes. Dimensions and constraints do not need to be shown. Good modeling practice must be followed. Note: all walls are same thickness. 15 8

9 9. Point P1 and line L1 are fixed, while point P2 is not. P1 is a distance of 3 units from line L1. If point P2 is constrained to be a distance of 5 units from P1 and 1 unit from L1, how many degrees-of-freedom remain for this system? Show how you arrived at this What does it mean when geometry is associative? How is this different from constrained geometry? Give examples of each Give three options that SolidWorks has for controlling where an extrude starts and where it ends Give two guidelines for avoiding problems with shelling. 2 9

10 13. Describe two ways of creating the solids shown in the figure. Give the names of operations and draw wireframe sketches as required. Dimensions and constraints do not need to be shown List one use for wireframe models, once they are done List one use for surface models, for which wireframe models cannot be used List one use for solid models, for which surface or wireframe models cannot be used A solid sphere has radius 5 and is centered at (5,5,0). What is the point-set classification of a point at (4,4,0)? 18. List three classes of solid model CREATION functions (not REPRESENTATION methods). 3 10

11 19. Shown below is a set of three primitive shapes combined in the given locations and orientations. In the space provided, sketch the two objects that would result from the two Boolean operations. A B C 6 (A B) C A B 11