Date of Award
Summer 2022
Document Type
Thesis
Degree Name
Master of Science (MS)
Department
Mechanical Engineering
First Advisor
Voglewede, Philip
Second Advisor
Kim, Kyuil
Third Advisor
Slaboch, Brian
Abstract
Planar multistable mechanisms are used throughout engineering to accomplish various tasks, for example residential electrical switching. The design of planar multistable mechanisms can be broken into four areas: determination of topology, geometric parameterization, analysis, and optimization. While topological determination, many analysis techniques, and optimization are well developed, geometric parameterization, which includes defining link lengths and spring stiffness, has largely been left to engineering judgement. This thesis presents a design methodology using potential energy graphs which informs engineering decisions made in choosing mechanism parameters for planar multistable mechanisms, giving designers higher confidence in the design. A kinematic analysis coupled with Lagrange's equation determines the relationship between the mechanism parameters and the potential energy curve. Plotting the potential energy with respect to the generalized coordinate yields a graph with a slope that is the generalized force. The relationships between parameters and their effects on the mechanism are difficult to observe in the equations of motion, but potential energy plots readily provide information pertinent to the design of planar multistable mechanisms and decouple their effects. This approach allows a simple kinematic design rather than a complex kinetic analysis which requires simulating differential equations, bridging the gap between the two analysis methods yielding a faster method that provides pertinent information. The design process is applied to three examples: a simple toggle mechanism, a compliant mechanism, and a reconfigurable mechanism to show the nuances of the approach. Future work to validate and improve the design process is discussed.