Download GTU (Gujarat Technological University) BE/BTech (Bachelor of Engineering / Bachelor of Technology) 2018 Winter 6th Sem New 2161903 Computer Aided Design Previous Question Paper
1
Seat No.: ________ Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE - SEMESTER ?VI (NEW) EXAMINATION ? WINTER 2018
Subject Code:2161903 Date:04/12/2018
Subject Name:Computer Aided Design
Time: 02:30 PM TO 05:00 PM Total Marks: 70
Instructions:
1. Attempt all questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
MARKS
Q.1 (a) State the various stages for a design process, in which various
CAD tools can be used to improve productivity.
03
(b) Explain different types of coordinate systems available in CAD
softwares.
04
(c) Plot intermediate raster locations when scan converting a straight
line from screen coordinate (2, 7) to screen coordinate (15, 10)
using DDA algorithm.
07
Q.2 (a) Explain the concept of homogeneous coordinates and its use in
representing geometrical transformation.
03
(b) Derive the matrix for orthographic projection matrices for the Top
view and Right Hand side view of a 3D model.
04
(c) Calculate the concatenated transformation matrix for the following
operations performed in the sequence as below:
i) Translation by 4 and 5 units along X and Y axis
ii) Change of scale by 2 units in X direction and 4 units in Y
direction
iii) Rotation by 60? in CCW direction about Z axis passing
through the point (4, 4).
Find new coordinates when the transformation is carried out on a
triangle ABC with A (4, 4), B (8, 4) and C (6, 8).
07
OR
(c) A triangle PQR with vertices P (2, 5), Q (6, 7) and R (2, 7) is to be
reflected about a line x = 2y ? 6. Determine, (i) The concatenated
matrix and (ii) The coordinates of the matrices for the reflected
triangle.
07
Q.3 (a) Explain different types of surfaces used in CAD modeling. 03
(b) Explain feature based modeling. 04
(c) Plot the Bezier curve having endpoints P0 (0, 0) and P3 (7, 0). The
other control points are P1 (7, 0) and P2 (7, 6). Plot values for u =
0, 0.1, 0.2, ?, 1, if the characteristic polygon is drawn in the
sequence P0 ? P1 ? P2 ? P3.
07
OR
Q.3 (a) Differentiate between Hermite Cubic Splines curves and Bezier
curves.
03
(b) What do you mean by Iso-parametric representations? Write the
equation of a line in parametric form.
04
www.FirstRanker.com www.FirstRanker.com
www.FirstRanker.com
FirstRanker.com - FirstRanker's Choice
www.FirstRanker.com
1
Seat No.: ________ Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE - SEMESTER ?VI (NEW) EXAMINATION ? WINTER 2018
Subject Code:2161903 Date:04/12/2018
Subject Name:Computer Aided Design
Time: 02:30 PM TO 05:00 PM Total Marks: 70
Instructions:
1. Attempt all questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
MARKS
Q.1 (a) State the various stages for a design process, in which various
CAD tools can be used to improve productivity.
03
(b) Explain different types of coordinate systems available in CAD
softwares.
04
(c) Plot intermediate raster locations when scan converting a straight
line from screen coordinate (2, 7) to screen coordinate (15, 10)
using DDA algorithm.
07
Q.2 (a) Explain the concept of homogeneous coordinates and its use in
representing geometrical transformation.
03
(b) Derive the matrix for orthographic projection matrices for the Top
view and Right Hand side view of a 3D model.
04
(c) Calculate the concatenated transformation matrix for the following
operations performed in the sequence as below:
i) Translation by 4 and 5 units along X and Y axis
ii) Change of scale by 2 units in X direction and 4 units in Y
direction
iii) Rotation by 60? in CCW direction about Z axis passing
through the point (4, 4).
Find new coordinates when the transformation is carried out on a
triangle ABC with A (4, 4), B (8, 4) and C (6, 8).
07
OR
(c) A triangle PQR with vertices P (2, 5), Q (6, 7) and R (2, 7) is to be
reflected about a line x = 2y ? 6. Determine, (i) The concatenated
matrix and (ii) The coordinates of the matrices for the reflected
triangle.
07
Q.3 (a) Explain different types of surfaces used in CAD modeling. 03
(b) Explain feature based modeling. 04
(c) Plot the Bezier curve having endpoints P0 (0, 0) and P3 (7, 0). The
other control points are P1 (7, 0) and P2 (7, 6). Plot values for u =
0, 0.1, 0.2, ?, 1, if the characteristic polygon is drawn in the
sequence P0 ? P1 ? P2 ? P3.
07
OR
Q.3 (a) Differentiate between Hermite Cubic Splines curves and Bezier
curves.
03
(b) What do you mean by Iso-parametric representations? Write the
equation of a line in parametric form.
04
www.FirstRanker.com www.FirstRanker.com
www.FirstRanker.com
www.FirstRanker.com
2
(c) Write short note on: Constructive Solid Geometry. 07
Q.4 (a) Draw a sketch of following elements showing nodes:
(i) Quadrilateral (ii) Six noded triangular (iii) Tetrahedral
03
(b) Explain penalty approach used in FEA with an example. 04
(c) Explain in details : The general procedure of Finite Element
Method
07
OR
Q.4 (a) List various engineering application of FEA. 03
(b) What do you mean by thermal effects of temperature ? How it is
included in calculation for 1-D elements?
04
(c) What is shape function? Derive linear shape functions for 1-
dimensional bar element in terms of natural coordinate. Also plot
variation of shape functions within this element.
07
Q.5 (a) List properties of global stiffness matrix [K]. 03
(b) Determine the temperature at x = 40 mm (Figure 1), if the
temperature at nodes Ti = 120 ?C, Tj = 80 ?C and xi = 10 mm and
xj = 60 mm. Consider linear shape function.
04
(c) With the help of suitable examples explain condition of plane
stress and plane strain.
07
OR
Q.5 (a) Write element stiffness matrix and element load vectors for a beam
element.
03
(b) What are axisymmetric elements? Explain. 04
(c) Consider the bar shown in Figure 2. An axial load P = 200 x 10
3
N
is applied as shown. Using the penalty approach for handling
boundary conditions,
(a) Determine the nodal displacements
(b) Determine the stress in each material.
(c) Determine the reaction forces.
07
A1 = 2400 mm
2
A2 = 600 mm
2
E1 = 70 x 10
9
N/m
2
E2 = 200 x 10
9
N/m
2
Figure 1 Figure 2
www.FirstRanker.com www.FirstRanker.com
www.FirstRanker.com
FirstRanker.com - FirstRanker's Choice
This post was last modified on 20 February 2020