Article
Mechanics
Tianyu Gu, Liang-Jiu Jia, Bo Chen, Min Xia, Hongyan Guo, Man-Chao He
Summary: This paper investigates the mechanical behaviors and monotonic plasticity of a new type of high strength and high ductility meta steel with negative Poisson's ratio effect. NPR steel exhibits a decrease in Poisson's ratio to 0.44 during the plastic stage and shows high uniform elongation and elongation till fracture. Experimental and numerical studies on the material were conducted, with a unified plasticity model and ductile fracture parameters presented for the steels.
ENGINEERING FRACTURE MECHANICS
(2021)
Article
Automation & Control Systems
Jiayi Kong, Keyue Ma Smedley, Hong Cheng
Summary: This article proposes a fixed on-time modulation (FTM) method for half-bridge series resonate converters (SRCs) to achieve full range regulation for all loads. The method features low current stresses, zero voltage switching turn-on for transistors and zero current switching turn-off for diodes. The article provides a comprehensive analysis on the operation principle, voltage gain curves, component stresses, and comparisons with other methods. Additionally, it discusses the extension of the FTM method to a family of half-bridge SRCs and provides voltage gains of different topologies. A 200 W prototype was built and tested for verification of the theoretical analysis.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2023)
Article
Automation & Control Systems
Wenhao Xie, Benjamin Y. Brown, Keyue Ma Smedley
Summary: This article introduces a new full-range regulation method for multilevel step-down RSCCs, along with corresponding advanced control techniques. Research shows that using this method can achieve efficient and high power density voltage converters.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2021)
Article
Engineering, Civil
Hamidreza Eipakchi, Farid Mahboubi Nasrekani
Summary: This article presents an analytical method to study the nonlinear frequency of composite cylindrical shells with metamaterial honeycomb core layer and adjustable Poisson's ratio. By changing the geometrical parameters of the honeycomb layer, a vast domain of the Poisson ratios from negative, zero, and positive values are accessible to achieve a composite structure with metamaterial behavior. The method allows for adjusting the linear natural frequency, coefficient of nonlinear frequency, and the weight of the shell by variations of the Poisson ratio.
THIN-WALLED STRUCTURES
(2021)
Article
Engineering, Manufacturing
Samantha McGuigan, Andrea P. Arguelles, Anne-Francoise Obaton, Alkan M. Donmez, Jacques Riviere, Parisa Shokouhi
Summary: The study investigates the feasibility of using resonance ultrasound spectroscopy (RUS) as an alternative nondestructive evaluation (NDE) method to inspect complex AM lattice structures with various numbers of missing struts. Numerical simulations suggest that pristine and defective lattice samples can theoretically be distinguished, and a similarity metric can be used to compare spectra after normalization. However, experimental results are less clear, possibly due to simplified material assumptions in numerical simulations and/or the presence of unaccounted defects and heterogeneities in test samples.
ADDITIVE MANUFACTURING
(2021)
Article
Materials Science, Multidisciplinary
H. Joshi, Tuan V. Vu, Nguyen N. Hieu, R. Khenata, D. P. Rai
Summary: An ab-initio density functional theory (DFT) method was utilized to investigate the elastic and thermodynamic properties of Fe2CoAl under hydrostatic pressure. It was found that the compound exhibits a mixture of covalent and ionic bonds, and shows ductility at all pressures considered, with various mechanical and dynamical properties showing linear changes under different applied pressures.
MATERIALS CHEMISTRY AND PHYSICS
(2021)
Article
Computer Science, Information Systems
Quan Sheng, Jingni Geng, Zheng Chang, Aihua Wang, Meng Wang, Shijie Fu, Wei Shi, Jianquan Yao
Summary: Wireless power transfer using a distributed laser resonator has potential for adaptive operation without alignment. In this study, we demonstrated an alignment-free laser with a large dynamic range for wireless power transfer. We obtained efficient optical and electrical outputs across different working distances and viewing angles. This research paves the way for practical applications in charging and communication for Internet of Things devices.
IEEE INTERNET OF THINGS JOURNAL
(2023)
Article
Engineering, Electrical & Electronic
Jong-Won Lim, Jamil Hassan, Minsung Kim
Summary: This article introduces a bidirectional soft-switching push-pull resonant converter that operates efficiently over a wide range of battery voltages, achieving almost zero-voltage switching at turn-off instants and maintaining high efficiency even during high-frequency operation. Additionally, the converter has a high conversion ratio in both power flow directions without the need for a transformer with a high turns ratio.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2021)
Article
Physics, Condensed Matter
Roderic S. Lakes, Ballard Huey, Karan Goyal
Summary: This study examines Poisson's ratio in chiral Cosserat elastic solids, revealing that chirality allows Poisson's ratio to exceed classical bounds and introducing a new perspective for investigating the mechanical properties of chiral rods.
PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS
(2022)
Article
Automation & Control Systems
Wenhao Xie, Keyue Ma Smedley
Summary: This article introduces a new full-range regulation method for step-up ladder RSCCs along with seven switching techniques. The ladder RSCCs with the proposed switching techniques feature the merits of simple control, soft switching, and high efficiency.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2022)
Article
Engineering, Electrical & Electronic
Weihua Gao, Jiantao Yao, Kunming Zhu, Pengwei Zhao, Xinbo Chen
Summary: This research proposes an innovative mechanical structure method by embedding a PDMS elastomer with negative Poisson's ratio (NPR) in a graphene-silicon rubber foam composite (rGO-PDMS/SR), which effectively improves the mechanical performance and resistance variation range for interactive information monitoring of multiple parts of the human body. The experimental results show that the rGO-PDMS/SR has expanded resistance variation range by six times compared to ordinary graphene-silicon rubber composites (rGO-SR), with high linear sensitivities and reliable stability during cyclic compression. Human interaction experiments demonstrate its good performance in signal detection for facial expression judgment, motion state monitoring, and other fields.
IEEE SENSORS JOURNAL
(2023)
Article
Engineering, Electrical & Electronic
Changkyu Bai, Minsung Kim
Summary: In this article, a bidirectional resonant converter with minimized switching loss is proposed. The converter achieves a wide voltage gain range in both forward and reverse operations by using a T-type active voltage doubler. The circuit design allows for almost zero voltage switching at turn-off instants, resulting in negligible switching loss. The converter demonstrates high efficiency and wide operating voltage range.
IEEE JOURNAL OF EMERGING AND SELECTED TOPICS IN POWER ELECTRONICS
(2022)
Article
Automation & Control Systems
Nam-Gyeong Kim, Seung-Won Jo, Byeongcheol Han, Han-Ho Choi, Minsung Kim
Summary: The proposed bidirectional resonant converter features a unique structure that minimizes switching loss over a wide voltage range and has been verified through experimentation. Different structures and operating modes are used on the high-voltage and low-voltage sides to achieve a high conversion ratio with low current ripple.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2021)
Article
Engineering, Mechanical
Ning Wang, Qingtian Deng
Summary: This study investigated the elastic properties of irregular honeycomb structures, finding that axial deformation has a significant influence on the structure. The elastic properties of the structure are affected by the enclosed area, shape, and material properties.
CHINESE JOURNAL OF MECHANICAL ENGINEERING
(2021)
Article
Physics, Applied
Christopher M. Kube, Zhangxi Feng, Ricardo A. Lebensohn, Matthew Cherry
Summary: Resonant ultrasound spectroscopy (RUS) is a mature technique for characterizing the elastic properties of solids. This article introduces an alternative constitutive law that considers initial strain or prestrain caused by residual stress, integrating it into the RUS framework. The model demonstrates the sensitivity of resonances to prestrain and supports RUS as a potential nondestructive method for characterizing prestrain in materials.
JOURNAL OF APPLIED PHYSICS
(2022)
