Download Design Project on Bike Frame - Mechanical Design I | ME 3614 and more Study Guides, Projects, Research Mechanical Systems Design in PDF only on Docsity! ME 3614 Mechanical Design I Fall Semester 2007 FE Design Project – Bike Frame Executive Summary Table Initial Model Final Model Max. Value Location Max. Value Location Max. Deflection (in) .071720 Element 7 .061840 Element 7 Max. Stress (psi) -1.589E4 Element 7 -2.178E4 Element 5 Factor of safety in yeilding 6.92 5.05 ME 3614 Mechanical Design I Fall Semester 2007 The goal of this project was for students to analyze a given bike frame that was placed under certain loads. The main objective of the project was to achieve a factor of safety of as close to 2 as possible without compromising the bikes stability. Students then used a mixture of what has been learned in Mechanical Design as well as a little bit of common sense to redesign the bike frame so that it would close to the desired factor of safety with as little deformation as possible and also to reduce the material used in some elements in order to decrease the frames weight. Figure 1: Bike with numbered nodes and elements The bike was to be made of 4140 Alloy Carbon Steel and an expected load of 150 lbf placed on the seat along with 25 lbf placed on the handlebars. The design was then given a load factor of 2.5, making the loads 375lbf and 62.5 lbf. While the initial bike was composed of a single material (16 gauge carbon steel tubing) there are two materials used on the final bike. Elements 1, 2 and 7 are made up of 14 gauge tubing while the rest of the elements are 22 gauge tubing. Due to the limitations of working in 2 dimensions the area and moment of inertia for the 14 gauge tubing was doubled because on a bike there would be two beams where each element is (one on either side of the wheel). Node 2 was fixed in both the x and y axis, while node 6 was fixed in only the y axis. In the final design of the bike the maximum displacement was .06184 inches in the x direction. This deformation occurred in element 7 of the frame. Element 7 was the critical member throughout the project (until the final model, when element 5 become the critical member). It took several tries of different gauges of tubing in order to find the
