Download GTU (Gujarat Technological University Ahmedabad) B.Tech/BE (Bachelor of Technology/ Bachelor of Engineering) 2020 Winter 6th Sem 2161903 Computer Aided Design Previous Question Paper
Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE- SEMESTER?VI (NEW) EXAMINATION ? WINTER 2020
Subject Code:2161903 Date:01/02/2021
Subject Name:Computer Aided Design
Time:02:00 PM TO 04:00 PM Total Marks: 56
Instructions:
1. Attempt any FOUR questions out of EIGHT questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
Q.1
(a) Clearly distinguish between conventional design and CAD.
03
(b) Explain different coordinate systems available in a CAD software.
04
(c) Write Breshnham's algorithm for line having slope less than 45.
07
Q.2
(a) What is homogenous coordinate system? Explain its importance in CAD. 03
(b) Write the differences between
04
(i) Raster scan and Vector scan displays
(ii) Analytic curves and Synthetic curves
(c) Reflect the diamond shaped polygon whose vertices are A(-1,0), B(0,-2), 07
C(1,0) and D(0,2) about
i) Horizontal line y = 2
ii) Vertical line x = 2
Q.3
(a) Explain plane surface and revolution surface in detail.
03
(b) The endpoints of a line are P1(2, 7, 12) and P2(5, 6, 4). Determine
04
(i) The parametric equation of line
(ii) Tangent vector of the line
(iii) Length of the line
(iv) Unit vector in the direction of the line
(c) Compare wireframe, surface and solid modeling techniques.
07
Q.4
(a) Discuss the structure of an IGES file.
03
(b) What are different representation schemes for solid models? Differentiate 04
between CSG and B-rep.
(c) The coordinates of four control points relative to a current WCS are given 07
by Bo[3 3 0]T, B1[3 4 0] T, B2[4 4 0] T, B3[4 3 0] T. Find the equation of the
resulting Bezier curve. Also find points on the curve for U = 0, 1/4, 1/2,
3/4, 1.
Q.5
(a) List the fields of applications of FEA.
03
(b) Explain Penalty approach to solve FEA problem.
04
(c) Discuss the steps involved in finite element analysis of a problem.
07
Q.6
(a) Explain curved shell elements in FEA.
03
(b) Discuss the properties of global stiffness matrix.
04
(c) Consider a two steeped bar as shown in Figure 1 below. Determine the 07
nodal displacements if the temperature raises by 50C. Consider E1
= 200 X 103 N/mm2, E2 = 70 X 103 N/mm2, A1 = 1000 mm2, A2 =
1
700 mm2, 1 = 11.7 X 10-6 per C, 2 = 23 X 10-6 per C. Take F =
100 KN.
Figure 1
Q.7
(a) With suitable examples explain plane stress condition. Which type of 03
element will you use to solve a plane stress problem with FEA?
(b) Derive the element stiffness matrix of a truss element.
04
(c) For the loading system shown in Figure 2 below, determine the 07
displacements and stresses. Assume modulus of elasticity E
= 80 X 103 N/mm2, cross sectional area A = 225mm2 and F = 90 KN.
Figure 2
Q.8
(a) Draw the following elements showing nodes
03
(i) 4 noded quadrilateral (ii) 3 noded triangle (iii) 8 noded hexahedron
(b) A 1D spar element having a linear shape function is as shown Figure 3 04
below. If the temperature at node 1 is 50 C and at node 2 is -20 C, find
the temperature at point P.
Figure 3
(c) Explain in detail the discretization process with respect to
07
(i) Types of elements (ii) Size of elements
(iii) Location of nodes (iv) Number of elements
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This post was last modified on 04 March 2021