Analysis, Design, and Optimization of Structures with Integral Compliant Mechanisms for Mid-Frequency Response

An analysis, design, and optimization methodology for structures that vibrate in the 1 kHz to 10 kHz frequency range has been developed. This methodology is the synthesis of several established research fields including structural dynamics, compliant mechanism design, finite element computational analysis, and structural optimization via an evolutionary algorithm.Ph.D.Mechanical EngineeringUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/60284/1/Dede_Dissertation.pd

Kilohertz magnetic field focusing in a pair of metallic periodic-ladder structures

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98699/1/ApplPhysLett_99_093501.pd

Generative design of large-scale fluid flow structures via steady-state diffusion-based dehomogenization

Abstract A computationally efficient dehomogenization technique was developed based on a bioinspired diffusion-based pattern generation algorithm to convert an orientation field into explicit large-scale fluid flow channel structures. Due to the transient nature of diffusion and reaction, most diffusion-based pattern generation models were solved in both time and space. In this work, we remove the temporal dependency and directly solve a steady-state equation. The steady-state Swift-Hohenberg model was selected due to its simplistic form as a single variable equation and intuitive parameter setting for pattern geometry control. Through comparison studies, we demonstrated that the steady-state model can produce statistically equivalent solutions to the transient model with potential computational speedup. This work marks an early foray into the use of steady-state pattern generation models for rapid dehomogenization in multiphysics engineering design applications. To highlight the benefits of this approach, the steady-state model was used to dehomogenize optimized orientation fields for the design of microreactor flow structures involving hundreds of microchannels in combination with a porous gas diffusion layer. A homogenization-based multi-objective optimization routine was used to produce a multi-objective Pareto set that explored the trade-offs between flow resistance and reactant distribution variability. In total, the diffusion-based dehomogenization method enabled the generation of 200 unique and distinctly different microreactor flow channel designs. The proposed dehomogenization approach permits comprehensive exploration of numerous bioinspired solutions capturing the full complexity of the optimization and Swift-Hohenberg design space

Collection of low-grade waste heat for enhanced energy harvesting

Enhanced energy harvesting through the collection of low-grade waste heat is experimentally demonstrated. A structural optimization technique is exploited in the design of a thermal-composite substrate to guide and gather the heat emanating from multiple sources to a predetermined location. A thermoelectric generator is then applied at the selected focusing region to convert the resulting low-grade waste heat to electrical power. The thermal characteristics of the device are experimentally verified by direct temperature measurements of the system and numerically validated via heat conduction simulations. Electrical performance under natural and forced convection is measured, and in both cases, the device with optimized heat flow control plus energy harvesting demonstrates increased power generation when compared with a baseline waste heat recovery system. Electronics applications include energy scavenging for autonomously powered sensor networks or self-actuated devices