Structure Design Physical Technology

Transcription

1 Name Twelve Corners Middle School Technology Education Mr. Priola Structure Design Physical Technology Structure design is a hands-on study that involves the application of the problem solving process & design process. Math, Science and Technology Education (MST - STEM) will be used, along with Civil Engineering principles, in the design and construction of your structure.

2 Structure Design Terms to Know Truss Member Span Compression Tension Shear Torsion

3 Structure Design Terms to Know Truss A group of members arranged geometrically to make a lightweight but strong structure. (One side of a bridge or tower.) Member One part or piece of a truss. Span Distance between two points. Compression An inward force that acts upon the top portion of the lower member of the truss/bridge. Tension An outward (stretching) force that acts upon the bottom portion of the lower member of the truss/bridge. Shear A force that cuts or severs. To become broken as a member under the action of a traverse or passing through force. Torsion A twisting or turning force.

4 Technology Education Problem Solving Process Identify & Define Problem Set Goals & List Rules (Desired Results & Limitations) Brainstorm & Research (Generate Alternatives) Select the Best Solution & Construct Test (Implement the Solution) Evaluate Results/Modify if Necessary

5 Assessments / Rubrics Work Log Habits of Mind 5 / 10 Days of Evaluation Total of 100 Points (20 points/day) 5% of 10 Week Average -Design Journal Assessment-

6 Technology Engineering Challenge Structure Design Your goal is to design and construct a structure/bridge that will hold the most weight on the least amount of money/materials. Your bridge will be judged by efficiency. Efficiency will be calculated by the amount of money you spend on materials divided by mass/weight that your bridge holds. E-Factor equals $ and this formula will be used to calculate your bridge lbs efficiency. The lower the efficiency number the more efficient your design! Your bridge must span a distance of ten inches. It must be between three to four inches wide and three to four inches high. (Any bridge that does not meet the measurement requirements will be DQ d.) You may laminate/sandwich pieces to increase strength, however, no more than 4 of lamination or overlap is allowed. Also, only (3) members will be allowed in any (1) lamination The first part of the assignment is to create five possible truss designs. Your bridge must be of truss design. (Five different designs from each group member.) Each partner will draw the designs as thumbnail sketches. From the thumbnails, each partner will draw a rough sketch and complete a cost estimation. You may patent/protect one of the designs and then your group will be required to complete a mechanical drawing of the front view. You will work in groups of two or three and you will be graded on a learning challenge, a design journal and the performance of the bridge on crunch day. Pricing -Wood ¼ by ¼ by 24 long $100.00/piece -Glue Hot Glue $50.00/bridge Wood Glue $50.00/bridge (Please note: Excessive or improper use of glue will result in a fine that will directly affect your efficiency factor and grade.) E-Factor equals $ lbs Prizes First Place Second Place Third Place Fourth Place All Others All Money Back, $300 Tech Dollars, Candy $300 Tech Dollars / Candy $250 Tech Dollars / Candy $200 Tech Dollars / Candy $150 Tech Dollars / Candy

7 In this step, transfer information from the Structure Design passage and place it in the proper location below as either the 1 st part of Step 2 or the 2 nd part of Step 2. Set Goal (Desired Results) (1 st Part of Step) List Rules (Limitations) (2 nd Part of Step) a b c d e f g h i

8 In this step, you think of solutions and perform two different types of sketches to put your thoughts on paper. - Thumbnail Sketches - Quick Sketches of ideas, no special tools are required. You can be the greatest inventor/designer in the world with pencil & paper! Thumbnail Sketches allow you to create alternative designs for your product; quickly communicate ideas; and graphically represent an idea/thought. Create 5 thumbnail sketches of a potential bridge truss. You may use the white space or graph lines. White Space: Graph Lines

9 - Rough Sketches - Rough Sketches allow you to refine your design. They are drawn with more detail, to the correct scale and you need to use a ruler. Based on your thumbnail sketches. Create (2) rough sketches of a Bridge Truss. Select (1) Rough Sketch Complete a Cost Estimation Steps 1. Select a thumbnail sketch and draw as rough sketch. 2. Confirm the length & height of your bridge. 3. Estimate the length of each member, label the Rough Sketch. 4. Add all the member lengths for one truss. 5. Multiply length of members for 1 truss by 2. (Two trusses per bridge.) 6. Divide length of members for bridge by 24. Round UP to the nearest whole number. (24 is length of wood. This step tells you how many pieces of wood you will have to purchase for 2 trusses.) 7. Multiply number of pieces per bridge by $100. ($100 is cost per piece.) 8. Add $50 to cost of wood for glue. (This step gives you total cost.) Show Work Below

10 - Rough Sketches - Rough Sketches allow you to refine your design. They are drawn with more detail, to the correct scale and you need to use a ruler. Based on your thumbnail sketches. Create (2) rough sketches of a Bridge Truss. Select (1) Rough Sketch Complete a Cost Estimation Steps 1. Select a thumbnail sketch and draw as rough sketch. 2. Confirm the length & height of your bridge. 3. Estimate the length of each member, label the Rough Sketch. 4. Add all the member lengths for one truss. 5. Multiply length of members for 1 truss by 2. (Two trusses per bridge.) 6. Divide length of members for bridge by 24. Round UP to the nearest whole number. (24 is length of wood. This step tells you how many pieces of wood you will have to purchase for 2 trusses.) 7. Multiply number of pieces per bridge by $100. ($100 is cost per piece.) 8. Add $50 to cost of wood for glue. (This step gives you total cost.) Show Work Below

11 - Mechanical (Technical) Drawing - Mechanical or technical drawings are the final step in the design process. They are a detailed drawing of the front view of your bridge truss and will be used a pattern for constructing your trusses/bridge. They are drawn with more detail, to the exact size/scale and they require drawing tools. You will use mechanical drawing paper; T-squares; triangles; drawing boards; pencil/eraser; duster; and you need to use a ruler. Based on your rough sketch, create (1) mechanical drawing of a Bridge Truss. The mechanical/technical drawing will be done on a drawing board. Look at the example below.

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14 Bridge Building Activity Bridge Testing Device The picture below is of the bridge-testing device. The following are procedures for testing. The span of the testing device is approximately 10. (Span refers to the distance between the black blocks that the bridge sets against.) Your bridge must be longer than the span. The bridge will be crushed by a 1 wide piece of steel. This piece is connected to a threaded rod that pulls down and applies pressure to the roadbed /lower members of the bridge. You must plan into your bridge design a place for the 1 piece of steel to fit through. The steel may be placed at a diagonal but it must be in direct contact with the roadbed or the members that are in direct contact with the black blocks. (Note the piece of steel at a diagonal.) Bridge Crusher With 10 Span & 1 Wide Flat Steel Crushing Bar

15 Design Journal - Last Entry Since your bridge will be destroyed, you not be able to modify the design. (You can re-glue/fix your bridge and submit to Mr. P for the next quarter demonstration. If you do, each group member will receive $100 tech dollars.) You will, however, be required to evaluate the results, (step 6 of PS process) by writing a journal entry that contains the following reflections: A prediction from your group; how much will your bridge hold? How did your bridge do in the competition? If we were to do the competition again o Would you change the design, how would you modify? Why? o Would you do an entirely new design? why? What did you learn from this activity?