ENERGY PROFILE AND BUCKLING BEHAVIOR OF BISTABLE PLASTIC COLUMN MEMBERS SUBJECTED TO A LATERAL MAGNETIC FORCE
Open Access
- Author:
- Murt, Daniel Thomas
- Area of Honors:
- Mechanical Engineering
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Paris R Vonlockette, Thesis Supervisor
Dr. Sean N Brennan, Thesis Honors Advisor - Keywords:
- bistable
hard magnets
buckling
snap-through - Abstract:
- In solid mechanics, a bistable structure is a structure that has two distinct states of stable mechanical equilibrium. Bistable structures are useful because they can achieve large structural deformations while only requiring a small amount of force to “snap-through” from one stable position to another. Given this snap-through behavior, bistable designs are useful for things like switches, valves, clasps, closures, and actuators, which require to be kept in one of two well-defined statically stable states for prolonged periods of time. One particularly common bistable system is a compressed column exhibiting buckling behavior in one of two stable positions. This paper investigates the use of hard magnets as a means to effect and manipulate the behavior of a bistable buckling column. Hard magnets, when implemented in a bistable buckling column, can achieve measurable changes in the loading and potential energy of the buckling column as a function of the buckling displacement of the column. Additionally, hard magnets are inexpensive, can be modeled as uniform dipoles, and require no external power supply to affect a bistable response. After running multiple buckling tests that fixed hard magnets to a midsection of an acrylic buckling specimen and at a specified proximity to the specimen in space, it was observed that hard magnets indeed noticeably modified the buckling behavior of the thin column. Specifically, the placement and orientation of the magnets were able to successfully modify the initial stiffness, maximum and critical loads, and the overall work done to the buckling column. Additionally, the hard magnets were found to be able to force buckling into one of two mechanically stable states by manipulating the initial distance between the magnets before buckling occurred.