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Full-Text Articles in Engineering
Optimization Of Energy Absorption Performance Of Polymer Honeycombs By Density Gradation, Oyindamola Rahman, Behrad Koohbor
Optimization Of Energy Absorption Performance Of Polymer Honeycombs By Density Gradation, Oyindamola Rahman, Behrad Koohbor
Henry M. Rowan College of Engineering Faculty Scholarship
Density gradation has been analytically and experimentally proven to enhance the load-bearing and energy absorption efficiency of cellular solids. This paper focuses on the analytical optimization (by virtual experiments) of polymeric honeycomb structures made from thermoplastic polyurethane to achieve density-graded structures with combined desired mechanical properties. The global stress-strain curves of single-density honeycomb structures are used as input to an analytical model that enables the characterization of the constitutive response of density-graded hexagonal honeycombs with discrete and continuous gradations and for various gradients. The stress-strain outputs are used to calculate the specific energy absorption, efficiency, and ideality metrics for all …
Sound Vortex Diffraction Via Topological Charge In Phase Gradient Metagratings, Yangyang Fu, Chen Shen, Xiaohui Zhu, Junfei Li, Youwen Liu, Steven A. Crummer
Sound Vortex Diffraction Via Topological Charge In Phase Gradient Metagratings, Yangyang Fu, Chen Shen, Xiaohui Zhu, Junfei Li, Youwen Liu, Steven A. Crummer
Henry M. Rowan College of Engineering Faculty Scholarship
Wave fields with orbital angular momentum (OAM) have been widely investigated in metasurfaces. By engineering acoustic metasurfaces with phase gradient elements, phase twisting is commonly used to obtain acoustic OAM. However, it has limited ability to manipulate sound vortices, and a more powerful mechanism for sound vortex manipulation is strongly desired. Here, we propose the diffraction mechanism to manipulate sound vortices in a cylindrical waveguide with phase gradient metagratings (PGMs). A sound vortex diffraction law is theoretically revealed based on the generalized conservation principle of topological charge. This diffraction law can explain and predict the complicated diffraction phenomena of sound …
Dispersion Tuning And Route Reconfiguration Of Acoustic Waves In Valley Topological Phononic Crystals, Zhenhua Tian, Chen Shen, Junfei Li, Eric Reit, Hunter Bachman, Joshua E. S. Socolar, Steven A. Crummer, Tony Jun Huang
Dispersion Tuning And Route Reconfiguration Of Acoustic Waves In Valley Topological Phononic Crystals, Zhenhua Tian, Chen Shen, Junfei Li, Eric Reit, Hunter Bachman, Joshua E. S. Socolar, Steven A. Crummer, Tony Jun Huang
Henry M. Rowan College of Engineering Faculty Scholarship
The valley degree of freedom in crystals offers great potential for manipulating classical waves, however, few studies have investigated valley states with complex wavenumbers, valley states in graded systems, or dispersion tuning for valley states. Here, we present tunable valley phononic crystals (PCs) composed of hybrid channel-cavity cells with three tunable parameters. Our PCs support valley states and Dirac cones with complex wavenumbers. They can be configured to form chirped valley PCs in which edge modes are slowed to zero group velocity states, where the energy at different frequencies accumulates at different designated locations. They enable multiple functionalities, including tuning …
Upgrading The Capstone Projects: The Engineering Clinic Model, Smitesh Bakrania, Ratneshwar Jha
Upgrading The Capstone Projects: The Engineering Clinic Model, Smitesh Bakrania, Ratneshwar Jha
Henry M. Rowan College of Engineering Faculty Scholarship
Capstone engineering design projects are ideal for broad application of engineering concepts on open-ended research and design problems. These projects allow students to reinforce their skills and extend their expertise into specialized areas of interest. Often, the capstone projects serve as both test grounds and launch pads for students’ engineering careers. Within the engineering curriculum, these projects typically span the final year of an engineering program and entail a single project within a single disciplinary area. While their significance to the educational experience is unequivocal, the benefits of a capstone project can be expanded to further reflect real-world experiences. Over …