Task

You and a teammate are to design and produce the following:

• A working, demountable structural model that can carry as much load as possible within the listed constraints of materials and geometry.
• An 8.5"x11" poster that graphically explains the structural mechanism of the model, and the way that you expect the model to fail under load.

Model Materials

• The materials are limited to the following:
• 1/16" thick or less chip board.
• 1/4" thick or less foam core board.
• Wood sticks with a cross section no larger than 1/8" x 1/8".
• Lightweight cotton twine (Duraline Cotton Wrapping Twine or equivalent. No rope. No nylon or other synthetics).

No adhesive products (e.g. tape or glue) are allowed in making the model.

In addition to making the model, you will also need to make a box to put it in, as described below.

Model Transport and Assembly

The model must be demountable and transportable in a box with the dimensions shown below. The dimensions are from outside face to outside face. You will need to make the box in addition to the model. Any materials are acceptable in making the box.

Each lab section will test during the regular lab time. The testing will be done in the 1st floor lounge. The schedule for testing will be as follows:

Model Loading and Supports

The figure shows a section diagram of the load and support conditions, The strap is 1.5 inches wide, and made of canvas. Note the following differences from past year's projects:

• The strap must go over the top of the structure, and so may not thread through it.
• No part of the unloaded structure may project more than 2 inches below the plane of the table top.
• The structure must rest on the table, and may not clamp, loop or attach in any other way.

Poster

The poster should provide clear, primarily graphic answers to the following two questions:

• How does your model work? (e.g. Is it a truss? a beam? an arch? Where are the connections and splices? How do the connections transfer load?)
• How do you think it will fail? (e.g. connection failure, buckling, roll-over, etc.)

You will submit the poster both in 8.5"x11" hard copy format, and as a PDF file to the submit directory of each team member.

Objectives and Evaluation

• Load carrying capacity: The amount of load the structure carries up to the point of collapse.
• Graphic explanation: The clarity of the poster in explaining the design reasoning and structural behavior.
• Teamwork: The ability to work productively in an assigned group.

These criteria will be evaluated as follows:

• Load carrying capacity: (70%) This will be based on the amount of load your structure carries.
• Graphic explanation: (20%) This will be based on my assessment of how clearly and accurately the poster addresses the questions listed under Poster above.
• Teamwork: (10%) This will be based on mutual assessment by you and your teammate using the Model Project Teamwork Form.

Deadline

Stop work at 11:00 AM, Thursday February 26 (for both sections). Models will be tested during the section meetings that day.