ENG H191 - Engineering Fundamentals and Laboratory I
Autumn 2002 - Bridge Design Project
Each two-person team is to design a method for spanning a gap approximately 16 inches in width between two supports. The design must be able to hold a minimum of two pounds with the load applied at the center. The materials to be used are two sheets of 8.5 x 11 inch cardboard that will be supplied by your instructor. You may use as much of the material in the two sheets as you would like but no more. The designs will be weighed to see if they are less than or equal to the average weight of two sheets of the cardboard supplied. You will not be able to use any fasteners or adhesives of any sort. This includes glue, stables, tape, etc. NOTHING. The structure may be up to 3.5 inches high but no wider than 3.0 inches.
On Monday, your team will brainstorm and sketch possible solutions for the project. The list of ideas will be hand written neatly on a sheet of engineering problem paper or a word processor. The sketches will be done on grid paper or green engineering problem paper with ideas identified with notes. You need to consider such things as shapes, assembly, how the shapes will be formed, and so on. Between the two of you, you should provide a list of five different possible designs that combine your various ideas. The five possible solutions must be sketched either on rectangular grid or isometric grid. These will be turned in with your design after your design has been tested.
On Tuesday, your team will get the cardboard (four sheets – two for practice and two for the final design) and scissors at the beginning of class. Choose your best two ideas from your brainstorming and preliminary ideas and decide on which one you will develop first. (You will keep the other idea ready to develop in case the first one doesn't work.) You will have much of the class period to work on Tuesday and approximately one hour on Wednesday. Please label your design with your team number and your names. In the first hour in class on Thursday, the bridges will be tested to determine whether they will support the required two pounds. Bridges that support at least two pounds are considered to meet the design guidelines. The bridges will be tested to destruction.
Your team may design for one or both of two strategies:
a) The lightest design to hold two pounds (best strength to weight ratio for the two pound load); or
b) The design that will hold the most weight but using no more than the two sheets of cardboard.
We will measure the size and weigh the designs before starting the testing. The size measurement will be made with a template with a rectangular hole 3.5 inches high and 3 inches wide. The weights (in one pound and half-pound increments) will be added to a bucket suspended from the center of the bridge until the bridge fails.
Grading - 55 points total
1. List of brainstorming ideas neatly written (on engineering problem paper
or word-processed).5
2. Sketches of the best five ideas (you may have more than one idea
per sheet)15
3. Decision criteria that your team used to decide on the best idea and
whether you were going for lightest to hold two pounds or to hold the
most weight. These are to be neatly hand written or done on a word
processor. Sketch the pattern that you used to create your design on
rectangular grid paper.10
4. Design meets size and weight specifications5
5. Design holds minimum required load20
TOTAL55
Bonuses (by class):
a) Lightest design to hold minimum required load5
b) Legal design that held the heaviest load5
1