MECHANICAL DESIGN

EXPLORING DESIGN WITH PROTOTYPING AND SIMULATION

The following are two-week long projects for an advanced mechanical design class. Each project makes use of fabrication methods in conjunction with SolidWorks modeling and finite element analysis to explore concepts such as material fatigue, failure loads, and various forms of stress. 

PROJECT 1: LASER-CUT BRACKET 

The purpose of this project was to create a design with minimal weight capable of supporting a 40-lb. weight. The bracket hangs off of support pegs in a testing stand while the suit clip attaches to the bottom of the bracket and the 40-lb. weight. The class average weight was just under 1.0 grams while my design weighed in at 0.77 grams and successfully held the weight without breaking. 

Many different geometries were explored, but I chose to fix to two support pegs instead of one so that the load is distributed more evenly. The V-shaped design carries the majority of the tensile stress from the weight while the cross-beams in the center of the V add strength to the bottom where the stresses are highest. 

PROJECT 2: 3D-PRINTED BRACKET

This project is very similar to the first with a few key differences - the bracket must be 3D-printed, only the bottom 8 pegs can be used, and the weight's support clip now has a moment. 

Because the bracket would be 3D printed, I chose to have my members in compression rather than tension to avoid shearing of the material. After comparing the relative stiffness per weight of a few different cross section geometries, I found that the square tube had the best strength per weight ratio. This final design successfully held the weight, though you can see it bending. It is comprised of two members (one horizontal and one at a small angle) that come together to reduce the moment of the pin connection. The final mass was around 1.1 grams and held 40 pounds of weight.