The acoustic black hole (ABH) effect for damping flexural waves using axially functionally graded porous (FGP) structure is investigated. With proposed power-law porosity of FGP structure, ABH can be achieved and damping effect is enhanced. The physics are explained from divergent conditions of the integrated wave phase at composite ends. Numerical results show the damping effect is increased with power law index. The phenomenon is expounded by the characteristics of reflection coefficient and impedance. It indicates that increasing power law index leads to smaller wavelength along to the end, then the wave needs more oscillation cycles to travel, which leads to more energy absorption. Transient analysis for 2D FGP structure also shows the focalization and ABH effect of the flexural waves.
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http://dx.doi.org/10.3390/ma12152480 | DOI Listing |
Poult Sci
November 2024
College of Animal Science and Technology, Northwest A&F University, Xianyang 712100, China. Electronic address:
The use of bio-enzyme as feed additives holds significant potential. This study aimed to evaluate the impact of a kind of compound bio-enzyme supplementation (the main functional components are probiotics and astragalus polysaccharides) on the production performance, serum immunity, and intestinal health of Pekin ducks. A total of 126 male Pekin ducks were randomly assigned to three groups: a control group (CG, no additive), a low-dose group (LG, 0.
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December 2024
Key Laboratory of Animal Disease-resistant Nutrition, Ministry of Education, Institute of Animal Nutrition, Sichuan Agricultural University, Sichuan Province, Chengdu 611130, China. Electronic address:
Biofabrication
July 2024
Research Institute for Medical and Biological Engineering, Ningbo University, Ningbo, Zhejiang 315211, People's Republic of China.
Various anisotropic tissue structures exist in organisms, including muscle tissue, skin tissue, and nerve tissue. Replicating anisotropic tissue structureshas posed a significant challenge. Three-dimensional (3D) printing technology is often used to fabricate biomimetic structures due to its advantages in manufacturing principle.
View Article and Find Full Text PDFMaterials (Basel)
June 2024
College of Mechanical Engineering, Zhejiang University of Technology, Hangzhou 310014, China.
This paper examines the accuracy and effectiveness of various beam theories in predicting the critical buckling loads and fundamental frequencies of functionally graded porous (FGP) beams whose material properties change continuously across the thickness. The beam theories considered are classical beam theory (CBT), first-order shear deformation beam theory (FSDBT), third-order shear deformation beam theory (TSDBT), and the broken-line hypothesis-based shear deformation beam theory (BSDBT). Governing equations for those beam theories are formulated by using the Hamilton's principle and are then solved by means of the generalised differential quadrature method.
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May 2024
State Key Laboratory of High Performance Complex Manufacturing, Central South University, Changsha 410083, China.
Based on the three-dimensional elasticity theory, the free vibration of functionally graded porous (FGP) sandwich rectangular plates is studied, and a unified solution for free vibration of the plates is proposed in this study. The arbitrary boundary conditions of FGP sandwich rectangular plates are simulated by using the Rayleigh-Ritz method combined with artificial spring theory. The calculation performances of the unified solution for FGP sandwich rectangular plates such as convergence speed and computational efficiency are compared extensively under different displacement functions.
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