ME 351Homework Assignments
 
Homework
Number
Due Date Problems or Link
1 12/9
I-DEAS 11 is installed on all the computers in Bogard Hall 301, 331, and 118A.Even though I-DEAS supports shared Team folders, we have not implemented this option. The default Team folder is simply stored on the hard disk of each computer as C:\Team\MyFiles. Unless you tell the program otherwise, that's where your I-DEAS model files will be stored. For security purposes, you will probably want to store your I-DEAS and Solid Edge data files on your network drive (E:). NOTE: I-DEAS has problems with directory paths that include spaces. Therefore, do NOT store your I-DEAS files in the standard My Documents folder. Create a folder on your E: drive, say, MEEN351, and store all of your I-DEAS files in that folder. All of the COES lab computers have 250 MB ZIP drives built in, so it would be wise to back all of your data files up on ZIP disks or a USB keyring storage device.

1. By the end of the quarter, you should have completed all 23 of the I-DEAS Part Modeling Level 1 tutorials. Pay special attention to I-DEAS Tutorial 13 - Extruding and revolving features. Submit the part created in steps 1-11 of this tutorial, and submit the printout of the final drawing and at least two intermediate steps.

For the problems listed below, print out a shaded isometric view (3D view) and a view of the part in the xy plane before you extrude or revolve it (show a few dimensions on this 2D plot):
2. Problem 1 of chapter 2 of the Parametric Modeling workbook.

3. Problem 4 of chapter 2 of the Parametric Modeling workbook.

2 12/10 The two web links that I pulled up in class are:
http://www.cs.princeton.edu/~min/cs426/classes/bezier.html
http://www.cl.cam.ac.uk/Teaching/1999/AGraphHCI/SMAG/node3.html

1. Implement the parametric equation of a line in Mathcad using the points (1,5) and (8,20). Present your Mathcad worksheet and the resulting Mathcad plot for your homework.

2. Implement the parametric equation of a circle in Mathcad with a radius of 10. Present your Mathcad worksheet and the resulting Mathcad plot for your homework. Show plots for 12 and 80 line segments that work to build the circle.

3. Write your first or last name using the Bezier Mathcad file passed around in class. Show how you arrived at your control points by turning in a hand written copy of each letter on a piece of graph paper with the control points indicated (as on the class handout). You can reference the Mathcad file handed out in class, but do not copy an electronic version of the file as you implement your solution. Turn in all of the required Mathcad worksheets and the plot of your name.

3 12/16 Draw the parts passed out in class. Print out a 2D drawing with dimensions as well as the final 3D drawing.
4 12/17 1. Consider the point (1  2   -3). Translate this point by +5 in the x direction and +2 in the y direction, and then rotate it by 30 degrees counter clockwise about the x axis. Perform these calculations (a) using Mathcad (b) by hand.

2. Consider a square (in the x-y plane) that is defined by the points (1,1), (2,1), (2,2) and (1,2). Make a Mathcad worksheet to complete the following:
(a) Print out a plot of the square without any transformations.
(b) Reflect your square about the y axis.
(c) Scale your square so that it is 1/3 as large in x and 2 times as large in the y. 
(d) Translate your square -4 in the x direction.
(e) Rotate your square 45 degrees counterclockwise.
(f) Translate your square to the origin (so that the original point (1,1) is moved to the origin), rotate by 45 degrees clockwise, then translate your square back to the original position (undo the first translation). This should result in a 45 degree clockwise rotation about point (1,1).

Start at the original position for (b) through (f), and print out plots for each transformation.  Make sure the plots are big enough to take up about 1/2 of a page and that the dimensions in the x and y directions are clearly showing.  Write each transformation matrix by hand on the printout of (a) through (f) so that I can clearly see the transformation matrix applied.

Print out your entire Mathcad file for (f).

5 1/6 1 and 2. Draw parts 1 and 2 passed out in class. Print out a 2D drawing with all the dimensions possible as well as a 3D drawing for each of these parts.

3. Go through chapter 5 of your I-DEAS 10 workbook entitled "Parametric Constraints Fundamentals." Using the techniques presented in this chapter, draw part 3 on the handout given in class. Create and establish three parametric relations for the part, and identify these features on your part (you can annotate your part by hand). Print out a 2D drawing with all the dimensions possible as well as a 3D drawing.

6 1/7 1. Create a 3rd order Bezier surface to approximate the shape of a bowl (with a circular shape at the top or rim of the bowl). The center of the bowl should roughly coincide with the origin of the coordinate system. Print out a 3D view of the bowl in Mathcad.

2. Rotate the bowl in problem 1 by 30 degrees counterclockwise about the x axis (counterclockwise when looking down the x-axis toward the origin). Print out a 3D plot of the rotated bowl and show your transformation matrix  (by hand or in Mathcad).

3. Translate the rotated bowl in problem 2 away from the origin. The x, y and z translation distances should be equal to the radius of the bowl (NOTE: This is different from what I said in class, since translating the bowl by xmean, ymean, and zmean would lead to no translation at all if the bowl in problem 1 was truly centered at the origin. I won't count off if you have already done it this way). Print out your entire Mathcad worksheet for this problem. The worksheet should include the transformation matrices in problems 2 and 3 as well as the 3D plot of the final translated and rotated bowl.

7 1/11 1. Complete the chapter in the I-DEAS workbook entitled "Feature Interactions and Reference Geometry." This is Chapter 7 in the I-DEAS 10 workbook. Print out an intermediate 2D view of the part as well as the final 3D part.

2. and 3. Draw the two parts on the handout given out in class. Print out a 2D view with dimensions and a 3D view of the final part.
8 1/14

1. Optimize a kingpost truss for minimum weight as in class for a span of 60 inches, an applied load of 1000 lbs, a yield strength of 40,000 psi, and a specific weight of the steel members of 0.284 lbs per cubic inch. However, include the additional influence of the potential buckling of members in compression (assume that the modulus of elasticity is 30,000,000 psi). Annotate your Mathcad worksheet to explain your work.  

a. Print out a plot containing four lines: one composite objective function that includes the influence of all members considering yielding and buckling failure, one for member AB in compression, one for member AD in tension, one for member BD in tension, and one for member AB considering buckling.
b. Give the optimum weight of the truss.
c. Give the diameter of the members at this optimum weight.

2. Find a public domain computer program or subroutine (such as CONMIN) on the web that can be used for constrained optimization problems.  Write a couple of paragraphs detailing what the program does and how it can be utilized to solve an optimization problem.  Give the  link(s) to the web page(s) where you found this information.

3. From http://www.ae.su.oz.au/wwwdocs/note1.html, define give some applications of shape optimization to continuum structures.

9 1/20

1. Complete the chapter in the I-DEAS workbook entitled "Assembly Modeling – Putting It All Together." This is Chapter 12 in the I-DEAS 10 workbook. Print out 3D views of each part as well as a 3D view of the final assembly. This will also require that you draw the bracket which is described in Chapter 11.
 
 2. On your own, draw an assembly that has at least three parts (you pick what you want to draw). Print out 3D views of each part and a 3D view of the assembly.

10 1/21 Complete the three practice tests on GD&T.
11 1/27 Draw the assembly based on the drawings given in class (see the class handout for specific requirements of this assignment).
12 1/28 Complete the two practice tests on GD&T.
13 2/3 Complete the assembly for the problem given in class (as described on the handout).
14 2/14 FEA stress concentration problem (hadnout).
15 2/17 2D truss analysis in Mathcad using the direct stiffness matrix (handout). The Mathcad file for the example worked in class is given here.

The homework solution is given here.

16 2/21 Coupled thermal / mechanical FEA problem (I-DEAS tutorial: Simulation > Simulation Projects > 27. Thermal Analysis)