Mechanical Engineering Department
BS in Mechanical Engineering
Polylogix is a team dedicated to the design, build, and testing of a fatigue machine to simulate cyclic loading on a biomedical polymer. This project is sponsored by Endologix, Inc. to provide test data characterizing mechanical material properties of various formulations of polymer used in abdominal aortic aneurysm surgeries. With this project goal, the machine must be able to test the polymer at body conditions; these include a testing temperature of 37°C and a cycling frequency ranging from 1 Hz to 10 Hz. This report proposes the following solution to this design challenge: an AC motor-driven mechanism utilizing a planetary gearbox and pulley system to reduce the speed of the motor to those necessary to achieve testing frequencies of 1 Hz, 2 Hz, 5 Hz, 8 Hz, and 10 Hz. From the drive mechanism, a shaft-mounted cam translates the rotational motion to linear motion through a cam follower. This cam follower carries a load cell and test specimen grip fixtures which clamp onto the specimen to apply cyclic loading. To vary the percent elongation applied to the test specimen, the cam has been designed to be interchangeable to accomplish a range of elongations: 10%, 20%, 30%, 40%, and 50%.