russ Design Challenge Experiment - Group 5

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Experiment Description: Students in the lab were tasked with designing a truss or bridge to span 400 mm and withstand a 100 lb load in a four-point flexure test. Requirements for the bridge included: • Span length of 400 mm • Width of 75 mm • Maximum height of 75 mm • Maximum weight of 100 grams • Must hold 45 kg (100 lbs) • No adhesives, such as glue, for connections The challenge lay in printing bridges in separate parts due to size limitations. Students had to design connections without adhesives, focusing on the weakest points: truss connections. Information on Group 5's Bridge: Group 5 designed a Warren Truss with an intermediate design consisting of 4 parts. Their focus was on resisting overturning failure using top and bottom cross braces in the middle, as well as corner braces. The bridge weighed 92 grams and resisted 85 lbs without failure. However, testing was challenging due to rounded nodes, which caused the loading bar to slip off before reaching the maximum load of 100 lbs. Group 5 recommended creating a flat platform on top of the truss at the nodes for design improvement. Note: A handout for this experiment will be available soon. When complete, a link will be provided in this description, allowing you to perform the experiment with your students.