Liya Zhao

Liya Zhao
UNSW Sydney | UNSW · School of Mechanical and Manufacturing Engineering

PhD

About

48
Publications
19,483
Reads
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1,549
Citations
Education
August 2011 - December 2015
Nanyang Technological University
Field of study
  • Structures and Mechanics
September 2005 - June 2009
Tongji University
Field of study
  • Civil Engineering

Publications

Publications (48)
Article
Full-text available
Energy harvesting from aeroelastic instabilities has attracted numerous interests with the purpose of implementing self-powered wireless sensing networks. Meanwhile, considerable efforts have been devoted to optimizing the interface circuit to boost the power output from vibration-based piezoelectric energy harvester, such as impedance matching, sy...
Article
Full-text available
In this article, we propose an easy but quite effective method to significantly enhance the power generation capability of an aeroelastic energy harvester. The method is to attach a beam stiffener to the substrate of the harvester, which works as an electromechanical coupling magnifier. It is shown to be effective for all three considered types of...
Article
Most piezoelectric aeroelastic energy harvesters operate effectively only at high wind speeds or within a narrow speed range. To overcome this issue, we propose a 2 degree-of-freedom (2DOF) piezoelectric aeroelastic energy harvester with a cut-out cantilever and two magnets. Translational galloping is induced with a square cross-sectioned bluff bod...
Article
Harvesting flow energy by exploiting transverse galloping of a bluff body attached to a piezoelectric cantilever is a prospective method to power wireless sensing systems. In order to better understand the electroaeroelastic behavior and further improve the galloping piezoelectric energy harvester (GPEH), an effective analytical model is required,...
Article
This letter presents a comparative study of different tip cross-sections for small scale wind energy harvesting based on galloping phenomenon. A prototype device is fabricated with a piezoelectric cantilever and a tip body with various cross-section profiles (square, rectangle, triangle, and D-shape) and tested in a wind tunnel. Experimental result...
Article
Harnessing energy from concurrent wind flow and base vibration is a prospective method to enable self-powered sensing in the circumstances where wind and base motion are coexisting, like aircrafts, bridges, railways and ocean buoys. This paper proposes a novel two-degree-of-freedom galloping energy harvester with 2:1 internal resonance for efficien...
Article
This paper presents a study of a two-degree-of-freedom (2DOF) piezoelectric energy harvester (PEH) under concurrent aeroelastic and base excitation. The governing equations of the theoretical model under the combined excitation are developed and solved analytically using the harmonic balance method. Based on the electro-mechanical analogies, an equ...
Article
Full-text available
Flow-induced vibration (FIV) energy harvesting has attracted extensive research interest in the past two decades. Remarkable research achievements and contributions from different aspects are briefly overviewed. Example applications of FIV energy harvesting techniques in the development of Internet of Things are mentioned. The challenges and diffic...
Article
Full-text available
In this study, based on the lumped-parameter theory and the Lagrange approach, a novel and generalized bending-torsional-axial coupled dynamic model for analyzing the load sharing behavior in the herringbone planetary gear train (HPGT) is presented by taking into account the actual structure of herringbone gears, manufacturing errors, time-dependen...
Article
This paper proposes a softening nonlinear aeroelastic galloping energy harvester for enhanced energy harvesting from concurrent wind flow and base vibration. Traditional linear aeroelastic energy harvesters have poor performance with quasi-periodic oscillations when the base vibration frequency deviates from the aeroelastic frequency. The softening...
Article
In this paper, a novel cantilever triboelectric energy harvester (TEH) working on the contact-separation mode is proposed for low-frequency vibration energy harvesting. An electro-mechanical model of TEH with non-parallel contact surfaces is derived by evaluating the total electrical energy between two surfaces. One merit of the proposed harvester...
Article
The cut‐in wind speed and the power output are the two main concerns of a galloping energy harvester. A good galloping energy harvester is expected to have a low cut‐in wind speed and a high power output. This paper proposes a two‐degree‐of‐freedom (2‐DOF) galloping‐based piezoelectric energy harvester (GPEH) by mounting a secondary beam onto a pri...
Article
Full-text available
This paper investigates a dynamic model and behavior of a novel double-beam piezo-magneto-elastic nonlinear wind energy harvester (DBPME-WEH). The DBPME-WEH is a double-beam structure, which contains the magnet-induced bistable nonlinearity to enhance the performance of the galloping-based vibration energy harvesting. The corresponding governing eq...
Article
Small-scale wind energy harvesting from vortex-induced vibrations (VIV) has been introduced in recent years as a renewable power source for microelectronics and wireless sensors. Previous studies have focused on modeling and optimizing the VIV-based piezoelectric energy harvester (VIVPEH) structures and simplified the complicated interface circuits...
Article
Full-text available
This Letter proposes a compact bistable galloping oscillator for achieving enhanced power generation from concurrent wind and base vibration. The harvester consists of a D-shaped bluff body attached to a piezoelectric cantilever, with magnetic interaction introduced between the bluff body and a fixed windward prism. Both theoretical analysis and ex...
Article
The aim of this study is to report a two-degree-of-freedom (2-DOF) string-driven rotor to convert ultra-low frequency vibrations to high-speed rotation motion of a rotor, which enables the efficient exploitation of ultra-low frequency mechanical energy. The proposed rotor structure consists of a disk-shaped rotor, a spring and two pieces of string,...
Article
This study proposes a cross-coupled dual-beam structure for energy harvesting from vortex-induced vibrations (VIV) induced by wind flows in different directions. A series of wind tunnel tests are conducted to investigate the performance of the proposed energy harvester subjected to the wind load with various speeds and directions. The upper and bot...
Article
Full-text available
This paper presents a novel energy harvesting device driven by concurrent aeroelastic vibration and base vibratory excitation. The harvester undergoes flow-induced limit-cycle oscillation under galloping instability, and at the same time, inertia force induced vibration is present due to the base vibratory excitation. A limitation with a traditiona...
Article
Full-text available
This paper presents an analysis of galloping-based wind energy harvesters with piezoelectric and electromagnetic transductions. The lumped parameter models of the galloping-based piezoelectric energy harvester (GPEH) and galloping-based electromagnetic energy harvester (GEMEH) are developed and the approximate analytical solutions of the equations...
Article
Galloping-based piezoelectric energy harvester (GPEH) has been used in power generation from small-scale airflows for low-power devices such as Micro-Electromechanical Systems (MEMS) and wireless sensing electronics. The bluff body plays an important role for the onset of galloping. Existing literature regarding analytical and numerical analysis of...
Conference Paper
In this paper, using a high frequency mechanical stopper as a complementary energy harvester is proposed to improve the performance of energy harvesting from concurrent wind flows and base vibrations. Galloping aeroelasticity of a square-sectioned bluff body is employed to achieve limit-cycle structural oscillations. The analysis demonstrates that...
Article
Full-text available
Whereas a lot of efforts have been put on energy conservation in wireless sensor networks (WSNs), the limited lifetime of these systems still hampers their practical deployments. This situation is further exacerbated indoors, as conventional energy harvesting (e.g., solar) may not always work. To enable long-lived indoor sensing, we report in this...
Article
This paper proposes a novel broadband energy harvester to concurrently harvest energy from base vibrations and wind flows by utilizing a mechanical stopper. A problem for a conventional wind energy harvester is that it can only effectively harness energy from two types of excitations around its resonance frequency. The proposed design consists of a...
Article
There has been growing research interest in converting ambient energy in the environment to electricity in order to realize self-powered electronic systems such as wireless sensor networks. This paper targets wind energy as an alternate power source. While structural modification of a wind energy harvester contributes to the power enhancement, the...
Article
Full-text available
The concept of harvesting ambient energy as an alternative power supply for electronic systems like remote sensors to avoid replacement of depleted batteries has been enthusiastically investigated over the past few years. Wind energy is a potential power source which is ubiquitous in both indoor and outdoor environments. The increasing research int...
Article
Full-text available
The interdisciplinary research area of small scale energy harvesting has attracted tremendous interests in the past decades, with a goal of ultimately realizing self-powered electronic systems. Among the various available ambient energy sources which can be converted into electricity, wind energy is a most promising and ubiquitous source in both ou...
Article
Full-text available
Recently, the concept of harvesting available energy from the surrounding environment of electronic devices to implement self-powered stand-alone units has attracted a dramatic increase in interest. Many studies have been conducted on the analytical solutions of output responses for vibration-based piezoelectric energy harvesters (VPEHs), with both...
Thesis
Full-text available
Wind energy is ubiquitous in both outdoor and indoor environments, yet small-scale energy harvesting aimed to harness power from wind with low speed (<10m/s) has received only limited attention. This thesis focuses on small-scale wind energy harvesting using smart structures with piezoelectric materials. An extensive literature survey on the state-...
Conference Paper
Full-text available
Galloping phenomenon has attracted extensive research attention for small-scale wind energy harvesting. In the reported literature, the dynamics and harvested power of a galloping-based energy harvesting system are usually evaluated with a resistive AC load; these characteristics might shift when a practical harvesting interface circuit is connecte...
Conference Paper
Full-text available
Wireless sensing systems have been widely exploited in structural health monitoring and environmental monitoring systems in order to ensure the integrity and reliability of infrastructures and their operating environment. Due to the continuously reduced power requirement of wireless sensing nodes, harvesting ambient energy to implement self-powered...
Conference Paper
Full-text available
A contemporary concept of externally coupling the vibration of a piezoelectric energy harvester with a parametrically excited beam to enhance the bandwidth of the whole system is presented in this paper. The proposed configuration not only serves in enhancing the bandwidth of operation of the harvester but also provides an option to utilize the con...
Article
Full-text available
Small-scale wind energy can be harvested for wireless sensing applications by exploiting the galloping phenomenon of a bluff body attached to a piezoelectric cantilever. Certain predictive model is required to understand the behavior of such a galloping-based piezoelectric energy harvester (GPEH). Conventional analytical and numerical models have s...
Conference Paper
Full-text available
Aeroelastic instabilities have been frequently exploited for energy harvesting purpose to power standalone electronic systems, such as wireless sensors. Meanwhile, various energy harvesting interface circuits, such as synchronized charge extraction (SCE) and synchronized switching harvesting on inductor (SSHI), have been widely pursued in the liter...
Conference Paper
Full-text available
Whereas a lot of efforts have been put on energy conservation in wireless sensor networks, the limited lifetime of these systems still hampers their practical deployments. This situation is further exacerbated indoors, as conventional energy harvesting (e.g., solar) ceases to work. To enable long-lived indoor sensing, we report in this paper a self...
Conference Paper
For indoor Wireless Sensor Networks (WSNs), as the conventional energy harvesting (e.g., solar) ceases to work in an indoor environment, the limited lifetime is still a threaten for practical deployment. We report in this demo a self-sustaining indoor sensing system. First of all, given the pervasive operation of heating, ventilation and air condit...
Conference Paper
Full-text available
A galloping piezoelectric harvester for small wind energy harvesting usually consists of a cantilever beam clamped at one end and a tip body attached to its free end. The tip body has significant influence on the aeroelastic characteristic of the harvester thus the efficiency of energy harvesting. However, no systematic study on the tip body is ava...
Conference Paper
A conventional vibration energy harvester is usually designed as a linear single-degree-of-freedom (1DOF) resonator. The efforts to improve its efficiency involve two aspects, i.e., enlarging the magnitude of output and widening the operating bandwidth. In this paper, we propose a magnetic coupled cantilever piezoelectric energy harvester (PEH) to...

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Projects

Project (1)
Project
Small-scale wind energy harvesting through aeroelasticities; efficiency enhancement with nonlinear structures/interfaces; concurrent wind and vibration energy harvesting