Open Access. Powered by Scholars. Published by Universities.®
- Keyword
- Publication
- Publication Type
Articles 1 - 2 of 2
Full-Text Articles in Mechanical Engineering
Loss-Induced Enhanced Transmission In Anisotropic Density-Near-Zero Acoustic Metamaterials, Chen Shen, Yun Jing
Loss-Induced Enhanced Transmission In Anisotropic Density-Near-Zero Acoustic Metamaterials, Chen Shen, Yun Jing
Henry M. Rowan College of Engineering Faculty Scholarship
Anisotropic density-near-zero (ADNZ) acoustic metamaterials are investigated theoretically and numerically in this paper and are shown to exhibit extraordinary transmission enhancement when material loss is induced. The enhanced transmission is due to the enhanced propagating and evanescent wave modes inside the ADNZ medium thanks to the interplay of near-zero density, material loss, and high wave impedance matching in the propagation direction. The equi-frequency contour (EFC) is used to reveal whether the propagating wave mode is allowed in ADNZ metamaterials. Numerical simulations based on plate-type acoustic metamaterials with different material losses were performed to demonstrate collimation and subwavelength imaging enabled by …
Design Maps For Fracture Resistant Functionally Graded Materials, Muhammad Ridwan Murshed
Design Maps For Fracture Resistant Functionally Graded Materials, Muhammad Ridwan Murshed
Theses and Dissertations
The objective of this research is to generate design maps to identify functionally graded microstructures with enhanced fracture toughness. Several Functionally Graded Materials (FGMs) with an edge crack and membrane loading are considered and the resulting J-integral values are computed numerically using Finite Element Analysis. In order to capture the resulting stress fields accurately, Barsoum elements are used in the vicinity of the crack tip and the simulations are carried out for several crack lengths (a) and material contrasts (κ). The averages of the J-integral values are used to determine the normalized Stress Intensity Factors which are then benchmarked with …