53125-mt----computeraided Design

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Code No: 53125/MT M.Tech. – I Semester Supplementary Examinations, September, 2008 COMPUTER AIDED DESIGN (CAD/CAM) Time: 3hours

Max. Marks:60 Answer any FIVE questions All questions carry equal marks ---

1.a) b) c)

Explain the various input and output devices used in a CAD system. Explain the different graphics standards used in a CAD system. What is a 21/2 D model? Sketch some examples.

2.a) Distinguish the terms topology and geometry. b) The coordinates of four control points relative to a current WCS are T T T T given by P0 = [ 2 2 0] , P1 [ 2 3 0] , P2 [3 3 0] , and P3 [3 2 0] . Find the equation of the resulting Bezier curve. Also find points on the curve for u=0, ¼, ½, ¾ and 1. c) What is convex hull of a Bezier curve? 3.a) b)

What are the advantages and disadvantages of surface models? Explain with the parametric representation of the following surfaces i) Plane surface ii) Ruled surface iii) Tabulated cylinder iv) Surface of revolution

Contd…2

Code No: 53125/MT

4.a)

b)

5.a) b) c) 6.a) b) c) 7.a) b) c)

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A triangle is defined in a two-dimensional ICG system by its vertices (0,2) (0,3) and (1,2). Perform the following transformation on this triangle. i) Translate the triangle in space by 2 units in the ‘x’ direction and 5 units in the ‘y’ direction. ii) Scale the original triangle by a factor of 1.5. iii) Scale the original triangle by a factor of 1.5 in the ‘x’ direction and 3.0 in the ‘y’ direction. iv) Rotate the original triangle by 45o about the origin. A line in two-dimensional space has end points defined by (1,1) and (1,3). It is desired to move this line by a series of transformations so that its end points will be at (0,1) and (0,5). i) Describe the sequence of transformations required to accomplish the movement of the line as specified. ii) For each transformation in the sequence, write the transformation matrix Explain the Constructive Solid Geometry (CSG) and Boundary representations(B-rep) with an example. What are the advantages and disadvantages of CSG representation? Explain the Euler’s law applied to closed polyhedral object. Why do you require data exchange and explain different types of translators? Explain the architecture of STEP format. Explain ACIS and DXF file formats. Explain the different types of geometric tolerances that are used in a CAD system. Explain the general procedure of the Finite Element Analysis (FEA). What is the difference between top-down and bottom-up approaches of mechanical assemblies that are used in any CAD system? And explain with an example.

8.a) What is Collaborative Engineering? And how it is applied to a product? b) Explain the principles of Collaborative design. c) What is the difference between the Internets, intranets, and extranets? ^*^*^