Abstract
A dual optimization method for optimizing contact-aided compliant mechanism design parameters and their spatial distribution in a dynamic ornithopter wing structure for increased pitch agility is presented. This methodology separates the task into two separate optimization problems where, first, a computationally efficient rigid-body dynamics model is used to determine the optimal stiffness and spatial distribution of the compliant mechanisms and, second, a detailed compliant mechanism design is developed and optimized that achieves the desired nonlinear stiffness. A rigid-body mechanics model of the wing structure is used to find the location and stiffness of a contact-aided compliant mechanism that will induce the forward sweep passively by coupling lift loads to forward sweep. The forward-swept compliant mechanism is then developed and optimized to achieve the desirable coupling. The free-flight pitch agility of an ornithopter is shown to increase via sweeping the wings forward during downstroke. A free-flight experiment is performed, and the novel contact-aided compliant mechanism is shown to induce the desired forward sweep during downstroke.
Original language | English (US) |
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Pages (from-to) | 3745-3756 |
Number of pages | 12 |
Journal | AIAA journal |
Volume | 56 |
Issue number | 9 |
DOIs | |
State | Published - 2018 |
All Science Journal Classification (ASJC) codes
- Aerospace Engineering