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A preliminary research on wireless cantilever beam vibration sensor in bridge health monitoring

Xinlong TONG, Shanglin SONG, Linbing WANG, Hailu YANG

《结构与土木工程前沿（英文）》 2018年第12卷第2期页码 207-214 doi: 10.1007/s11709-017-0406-x

摘要： According to specific bridge environment, optimal design piezoelectric cantilever beam structure by using results of theoretical calculations and simulation, verify natural frequencies of piezoelectric cantilever beam and production ability of data by experiment, thus formed a complete set of design method of piezoelectric cantilever beam. Considering natural frequency of vibration and intensity of the beam body, design a new type of piezoelectric cantilever beam structure. Paper analyzes the principle of sensor data acquisition and transmission, design a hardware integration system include signal conversion module, microcontroller module and wireless transmission module, test local read and wireless transmission for the combination structure of cantilever beam and data collection card, experimental verification of the radio piezoelectric vibrating cantilever vibration response is intact, the beam produced signal by vibration, acquisition card converts and wireless transmit data, this proved a good and intuitive linear response in simulation of bridge vibration test. Finally, the paper designed a kind of new wireless sensor of vibration cantilever beam, suitable for small bridge health monitoring based on Internet of things.

关键词： piezoelectric cantilever beam bridge natural frequency wireless sensor

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Detection of void and metallic inclusion in 2D piezoelectric cantilever beam using impedance measurements

S. SAMANTA, S. S. NANTHAKUMAR, R. K. ANNABATTULA, X. ZHUANG

《结构与土木工程前沿（英文）》 2019年第13卷第3期页码 542-556 doi: 10.1007/s11709-018-0496-0

摘要： The aim of current work is to improve the existing inverse methodology of void-detection based on a target impedance curve, leading to quick-prediction of the parameters of single circular void. In this work, mode-shape dependent shifting phenomenon of peaks of impedance curve with change in void location has been analyzed. A number of initial guesses followed by an iterative optimization algorithm based on univariate method has been used to solve the problem. In each iteration starting from each initial guess, the difference between the computationally obtained impedance curve and the target impedance curve has been reduced. This methodology has been extended to detect single circular metallic inclusion in 2D piezoelectric cantilever beam. A good accuracy level was observed for detection of flaw radius and flaw-location along beam-length, but not the precise location along beam-width.

关键词： piezoelectricity impedance curve mode shapes inverse problem flaw detection curve shifting

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Crack detection of the cantilever beam using new triple hybrid algorithms based on Particle Swarm Optimization

Amin GHANNADIASL; Saeedeh GHAEMIFARD

《结构与土木工程前沿（英文）》 2022年第16卷第9期页码 1127-1140 doi: 10.1007/s11709-022-0838-9

摘要： The presence of cracks in a concrete structure reduces its performance and increases in the size of cracks result in the failure of the structure. Therefore, the accurate determination of crack characteristics, such as location and depth, is one of the key engineering issues for assessment of the reliability of structures. This paper deals with the inverse analysis of the crack detection problems using triple hybrid algorithms based on Particle Swarm Optimization (PSO); these hybrids are Particle Swarm Optimization-Genetic Algorithm-Firefly Algorithm (PSO-GA-FA), Particle Swarm Optimization-Grey Wolf Optimization-Firefly Algorithm (PSO-GWO-FA), and Particle Swarm Optimization-Genetic Algorithm-Grey Wolf Optimization (PSO-GA-GWO). A strong correlation exists between the changes in the natural frequency of a concrete beam and the crack parameters. Thus, the location and depth of a crack in a beam can be predicted by measuring its natural frequency. Hence, the measured natural frequency can be used as the input parameter of the algorithm. In this paper, this is applied to identify crack location and depth in a cantilever beam using the new hybrid algorithms. The results show that among the proposed triple hybrid algorithms, the PSO-GA-FA and PSO-GWO-FA algorithms are much more effective than PSO-GA-GWO algorithm for the crack detection.

关键词： crack cantilever beam triple hybrid algorithms Particle Swarm Optimization

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Modeling and analysis of controllable output property of cantilever-beam inertial sensors based on magnetic

Guixiong LIU, Peiqiang ZHANG, Chen XU

《机械工程前沿（英文）》 2009年第4卷第2期页码 129-133 doi: 10.1007/s11465-009-0035-8

摘要： Magnetic fluid is first introduced into the traditional cantilever-beam senor. Based on the property of the cantilever-beam and the novel controllable mag-viscosity of magnetic fluid, the output of cantilever-beam sensors is under control so that the controllable output of the sensors can be realized. The mathematical model of the sensors is established and analyzed. The dynamic control function and the following educational results, which include the two curves of the displacement ratio and phase function with the different damping ratio and frequency ratio, are obtained based on the model. The result shows that it is valid to realize the controllable output of the sensors by controlling the viscosity of the magnetic fluid, and finally the expanded measurement range can be realized.

关键词： sensors magnetic fluid property of mag-viscosity controllable output

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Impact drive rotary precision actuator with piezoelectric bimorphs

ZHANG Hongzhuang, ZENG Ping, HUA Shunming, CHENG Guangming, YANG Zhigang

《机械工程前沿（英文）》 2008年第3卷第1期页码 71-75 doi: 10.1007/s11465-008-0008-3

摘要： An impact drive rotary precision actuator with end-loaded piezoelectric cantilever bimorphs is proposed. According to finite element analysis and experiments of the dynamic characteristics of end-loaded piezoelectric cantilever bimorphs, a specific fixed-frequency and adjustable-amplitude is confirmed to control the actuator. The results show that an actuator excited by fixed-frequency and the adjustable-amplitude ramp voltage waveform works with a large travel range (180°), high resolution (1 ?rad), speed (0.2 rad/min) and heavy-load ability (0.02 Nm). With advantages of high-precision positioning ability, simple structure and only one percent the cost of traditional impact drive mechanisms, the actuator is expected to be widely used in precision industries.

关键词： specific fixed-frequency waveform piezoelectric cantilever mechanisms adjustable-amplitude

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PRESS-based EFOR algorithm for the dynamic parametrical modeling of nonlinear MDOF systems

Haopeng LIU, Yunpeng ZHU, Zhong LUO, Qingkai HAN

《机械工程前沿（英文）》 2018年第13卷第3期页码 390-400 doi: 10.1007/s11465-017-0459-5

摘要：

In response to the identification problem concerning multi-degree of freedom (MDOF) nonlinear systems, this study presents the extended forward orthogonal regression (EFOR) based on predicted residual sums of squares (PRESS) to construct a nonlinear dynamic parametrical model. The proposed parametrical model is based on the non-linear autoregressive with exogenous inputs (NARX) model and aims to explicitly reveal the physical design parameters of the system. The PRESS-based EFOR algorithm is proposed to identify such a model for MDOF systems. By using the algorithm, we built a common-structured model based on the fundamental concept of evaluating its generalization capability through cross-validation. The resulting model aims to prevent over-fitting with poor generalization performance caused by the average error reduction ratio (AERR)-based EFOR algorithm. Then, a functional relationship is established between the coefficients of the terms and the design parameters of the unified model. Moreover, a 5-DOF nonlinear system is taken as a case to illustrate the modeling of the proposed algorithm. Finally, a dynamic parametrical model of a cantilever beam is constructed from experimental data. Results indicate that the dynamic parametrical model of nonlinear systems, which depends on the PRESS-based EFOR, can accurately predict the output response, thus providing a theoretical basis for the optimal design of modeling methods for MDOF nonlinear systems.

关键词： MDOF dynamic parametrical model NARX model PRESS-based EFOR cantilever beam

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Seismic behavior of cantilever wall embedded in dry and saturated sand

Sanku KONAI, Aniruddha SENGUPTA, Kousik DEB

《结构与土木工程前沿（英文）》 2020年第14卷第3期页码 690-705 doi: 10.1007/s11709-020-0615-6

摘要： The embedded cantilever retaining walls are often required for excavation to construct the underground facilities. Significant numbers of numerical and experimental studies have been performed to understand the behavior of embedded cantilever retaining walls under static condition. However, very limited studies have been conducted on the behavior of embedded retaining walls under seismic condition. In this paper, the behavior of a small scale model embedded cantilever retaining wall in dry and saturated sand under seismic loading condition is investigated by shake table tests in the laboratory and numerically using software FLAC2D. The embedded cantilever walls are subjected to sinusoidal dynamic motions. The behaviors of the cantilever walls in terms of lateral displacement and bending moment are studied with the variation of the two important design parameters, peak amplitude of the base motions and excavation depth. The variation of the pore water pressures within the sand is also observed in the cases of saturated sand. The maximum lateral displacement of a cantilever wall due to seismic loading is below 1% of the total height of the wall in dry sand, but in case of saturated sand, it can go up to 12.75% of the total height of the wall.

关键词： embedded cantilever wall shake table test FLAC2D seismic loading saturated and dry sand

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Research on applications of piezoelectric materials in smart structures

Jinhao QIU, Hongli JI

《机械工程前沿（英文）》 2011年第6卷第1期页码 99-117 doi: 10.1007/s11465-011-0212-4

摘要：

Piezoelectric materials have become the most attractive functional materials for sensors and actuators in smart structures because they can directly convert mechanical energy to electrical energy and vise versa. They have excellent electromechanical coupling characteristics and excellent frequency response. In this article, some research activities on the applications of piezoelectric materials in smart structures, including semi-active vibration control based on synchronized switch damping using negative capacitance, energy harvesting using new electronic interfaces, structural health monitoring based on a new type of piezoelectric fibers with metal core, and active hysteresis control based on new modified Prandtl-Ishlinskii model at the Aeronautical Science Key Laboratory for Smart Materials and Structures, Nanjing University of Aeronautics and Astronautics are introduced.

关键词： piezoelectric materials vibration control energy harvesting structural health monitoring piezoelectric hysteresis

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Present situation and classification of piezoelectric pump

Fang YE, Shouyin WANG, Wei CHENG, Qixiao XIA, Jianhui ZHANG,

《机械工程前沿（英文）》 2009年第4卷第4期页码 420-429 doi: 10.1007/s11465-009-0052-7

摘要： According to the present classification method for a piezoelectric pump, this paper reviews the development and present situation of piezoelectric pumps in the latest 30 years and finally puts forward a new classification. A volumetric piezoelectric pump, which belongs to traditional volumetric pumps, can be divided into a piezoelectric pump with or without valves. A new valveless piezoelectric pump nowadays becomes a hot issue in scientific research. It is constructed by using no-moving-part valves, which can induce positive flow resistance and negative flow resistance different, and in which the inlet and outlet are connected all the time. New forms of piezoelectric pumps, different from traditional ones, are only at the stage of conception and principle, and no practical application has been reported.

关键词： piezoelectric pump development and present situation new classification method valveless piezoelectric pump new forms of piezoelectric pump

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A hierarchical system to predict behavior of soil and cantilever sheet wall by data-driven models

Nang Duc BUI; Hieu Chi PHAN; Tiep Duc PHAM; Ashutosh Sutra DHAR

《结构与土木工程前沿（英文）》 2022年第16卷第6期页码 667-684 doi: 10.1007/s11709-022-0822-4

摘要： The study proposes a framework combining machine learning (ML) models into a logical hierarchical system which evaluates the stability of the sheet wall before other predictions. The study uses the hardening soil (HS) model to develop a 200-sample finite element analysis (FEA) database, to develop the ML models. Consequently, a system containing three trained ML models is proposed to first predict the stability status (random forest classification, RFC) followed by 1) the cantilever top horizontal displacement of sheet wall (artificial neural network regression models, RANN1) and 2) vertical settlement of soil (RANN2). The uncertainty of this data-driven system is partially investigated by developing 1000 RFC models, based on the application of random sampling technique in the data splitting process. Investigation on the distribution of the evaluation metrics reveals negative skewed data toward the 1.0000 value. This implies a high performance of RFC on the database with medians of accuracy, precision, and recall, on test set are 1.0000, 1.0000, and 0.92857, respectively. The regression ANN models have coefficient of determinations on test set, as high as 0.9521 for RANN1, and 0.9988 for RANN2, respectively. The parametric study for these regressions is also provided to evaluate the relative insight influence of inputs to output.

关键词： finite element analysis cantilever sheet wall machine learning artificial neural network random forest

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Robust isogeometric topology optimization for piezoelectric actuators with uniform manufacturability

《机械工程前沿（英文）》 2022年第17卷第2期 doi: 10.1007/s11465-022-0683-5

摘要： Piezoelectric actuators have received substantial attention among the industry and academia due to quick responses, such as high output force, high stiffness, high accuracy, and precision. However, the design of piezoelectric actuators always suffers from the emergence of several localized hinges with only one-node connection, which have difficulty satisfying manufacturing and machining requirements (from the over- or under-etching devices). The main purpose of the current paper is to propose a robust isogeometric topology optimization (RITO) method for the design of piezoelectric actuators, which can effectively remove the critical issue induced by one-node connected hinges and simultaneously maintain uniform manufacturability in the optimized topologies. In RITO, the isogeometric analysis replacing the conventional finite element method is applied to compute the unknown electro elastic fields in piezoelectric materials, which can improve numerical accuracy and then enhance iterative stability. The erode–dilate operator is introduced in topology representation to construct the eroded, intermediate, and dilated density distribution functions by non-uniform rational B-splines. Finally, the RITO formulation for the design of piezoelectric materials is developed, and several numerical examples are performed to test the effectiveness and efficiency of the proposed RITO method.

关键词： piezoelectric actuator isogeometric topology optimization uniform manufacturability robust formulation density distribution function

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Novel precision piezoelectric step rotary actuator

LIU Jianfang, YANG Zhigang, ZHAO Hongwei, CHENG Guangming

《机械工程前沿（英文）》 2007年第2卷第3期页码 356-360 doi: 10.1007/s11465-007-0062-2

摘要： A novel piezoelectric (PZT) precision step rotary actuator was developed on the basis of PZT technology. It adopts the principle of bionics and works with an inside anchoring/loosening of the stator and a distortion structure of the uniformly distributed thin flexible hinge to solve problems such as ineffective anchoring/loosening, low step rotary frequency, small travel, poor resolution, low speed and unsteady output. The developed actuator is characterized by high frequency (30 Hz), high speed (380 μrad/s), large travel (>270º), high resolution (1 μrad/step), and work stability. It greatly improves the ability to drive the existing PZT step rotary actuator. The new actuator can be applied in the field of micromanipulation and precision engineering, including precision driving and positioning and optics engineering.

关键词： developed stability ineffective anchoring/loosening technology piezoelectric

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A valveless piezoelectric pump with novel flow path design of function of rectification to improve energy

《机械工程前沿（英文）》 2022年第17卷第3期 doi: 10.1007/s11465-022-0685-3

摘要： Existing valveless piezoelectric pumps are mostly based on the flow resistance mechanism to generate unidirectional fluid pumping, resulting in inefficient energy conversion because the majority of mechanical energy is consumed in terms of parasitic loss. In this paper, a novel tube structure composed of a Y-shaped tube and a ȹ-shaped tube was proposed considering theory of jet inertia and vortex dissipation for the first time to improve energy efficiency. After verifying its feasibility through the flow field simulation, the proposed tubes were integrated into a piezo-driven chamber, and a novel valveless piezoelectric pump with the function of rectification (NVPPFR) was reported. Unlike previous pumps, the reported pump directed the reflux fluid to another flow channel different from the pumping fluid, thus improving pumping efficiency. Then, mathematical modeling was established, including the kinetic analysis of vibrator, flow loss analysis of fluid, and pumping efficiency. Eventually, experiments were designed, and results showed that NVPPFR had the function of rectification and net pumping effect. The maximum flow rate reached 6.89 mL/min, and the pumping efficiency was up to 27%. The development of NVPPFR compensated for the inefficiency of traditional valveless piezoelectric pumps, broadening the application prospect in biomedicine and biology fields.

关键词： composite tube valveless piezoelectric pump rectification energy efficiency

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optimization for tailoring the ratio between two flexural eigenfrequencies of atomic force microscopy cantilever

Qi XIA,Tao ZHOU,Michael Yu WANG,Tielin SHI

《机械工程前沿（英文）》 2014年第9卷第1期页码 50-57 doi: 10.1007/s11465-014-0286-x

摘要：

In an operation mode of atomic force microscopy that uses a higher eigenmode to determine the physical properties of material surface, the ratio between the eigenfrequency of a higher flexural eigenmode and that of the first flexural eigenmode was identified as an important parameter that affects the sensitivity and accessibility. Structure features such as cut-out are often used to tune the ratio of eigenfrequencies and to enhance the performance. However, there lacks a systematic and automatic method for tailoring the ratio. In order to deal with this issue, a shape and topology optimization problem is formulated, where the ratio between two eigenfrequencies is defined as a constraint and the area of the cantilever is maximized. The optimization problem is solved via the level set based method.

关键词： atomic force microscopy cantilever probe eigenfrequency optimization

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Boundary conditions for axisymmetric piezoelectric cylinder

Baosheng ZHAO, Di WU, Xi CHEN

《机械工程前沿（英文）》 2013年第8卷第4期页码 401-408 doi: 10.1007/s11465-013-0272-8

摘要：

For axisymmetric piezoelectric cylinder, the reciprocal theorem and the axisymmetric general solution of piezoelasticity are applied in a novel way to obtain the appropriate stress and mixed boundary conditions accurate to all orders for the cylinder of general edge geometry and loadings. A decay analysis technique developed by Gregory and Wan is converted into necessary conditions on the end-data of axisymmetric piezoelectric circular cylinder, and the rapidly decaying solution is established. The prescribed end-data of the circle cylinder must satisfy these conditions in order that they could generate a decaying state within the cylinder. When stress and mixed conditions are imposed on the end of cylinder, these decaying state conditions for the case of axisymmetric deformation of piezoelectric cylinder are derived explicitly. They are then used for the correct formulation of boundary conditions for the theory solution (or the interior solution) of axisymmetric piezoelectric cylinder. The results of the present paper enable us to establish a set of correct boundary conditions, most of which are obtained for the first time.

关键词： solid and structures the axisymmetric deformation the piezoelectric circular cylinder the refined theory Bessel’s Function