Pub Date : 2024-07-25DOI: 10.1088/1361-665x/ad6797
Meng Ren, Xiangdi Meng, Mingxi Deng
This paper presents an effective method for evaluating the impact damage of composite plates using zero-group-velocity (ZGV) Lamb waves. A finite element (FE) model of the carbon fiber-reinforced polymer (CFRP) plate is established to analyze in detail the propagation characteristics of the S1-ZGV Lamb wave mode with a specified propagation direction. The study investigates the changes in the S1-ZGV mode with varying damage levels, characterized by a decrease in elastic moduli. Results indicate that as the damage level increases, the corresponding S1-ZGV frequency and amplitude decrease proportionally. The spectral amplitude at the initial S1-ZGV frequency exhibits a consistent and significant decrease with increasing damage levels, offering a reliable method for accurately assessing damage in CFRP plates. Additionally, the S1-ZGV mode of the CFRP plate is experimentally excited using the pitch-catch technique with air-coupled ultrasonic transducers to explore the variations in the S1-ZGV mode with different impact damages. Experimental findings show that the spectral amplitude of the S1-ZGV mode at the initial S1-ZGV frequency decreases monotonically and sensitively with an increasing number of impacts. These experimental results correlate with the FE analysis, validating the effectiveness of accurately evaluating impact damage in CFRP plates based on the spectral amplitude of S1-ZGV modes.
{"title":"Evaluating impact damage on carbon fiber-reinforced polymer plates utilizing zero-group-velocity Lamb waves","authors":"Meng Ren, Xiangdi Meng, Mingxi Deng","doi":"10.1088/1361-665x/ad6797","DOIUrl":"https://doi.org/10.1088/1361-665x/ad6797","url":null,"abstract":"\u0000 This paper presents an effective method for evaluating the impact damage of composite plates using zero-group-velocity (ZGV) Lamb waves. A finite element (FE) model of the carbon fiber-reinforced polymer (CFRP) plate is established to analyze in detail the propagation characteristics of the S1-ZGV Lamb wave mode with a specified propagation direction. The study investigates the changes in the S1-ZGV mode with varying damage levels, characterized by a decrease in elastic moduli. Results indicate that as the damage level increases, the corresponding S1-ZGV frequency and amplitude decrease proportionally. The spectral amplitude at the initial S1-ZGV frequency exhibits a consistent and significant decrease with increasing damage levels, offering a reliable method for accurately assessing damage in CFRP plates. Additionally, the S1-ZGV mode of the CFRP plate is experimentally excited using the pitch-catch technique with air-coupled ultrasonic transducers to explore the variations in the S1-ZGV mode with different impact damages. Experimental findings show that the spectral amplitude of the S1-ZGV mode at the initial S1-ZGV frequency decreases monotonically and sensitively with an increasing number of impacts. These experimental results correlate with the FE analysis, validating the effectiveness of accurately evaluating impact damage in CFRP plates based on the spectral amplitude of S1-ZGV modes.","PeriodicalId":21656,"journal":{"name":"Smart Materials and Structures","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141804032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-24DOI: 10.1088/1361-665x/ad649c
Guo-Yu Zhang, Zi-Jiang Liu, Bing-Zu Li, Xi-Long Dou, Cai-Rong Zhang, Xiao-Wei Sun and Yi-Man Yang
Using phononic crystals (PnCs) to enhance the electrical output performance of piezoelectric energy harvesting (PEH) devices and broaden the frequency range of harvesting energy is crucial to solving the self-energy of low-power devices such as wireless sensors. In this work, an ultra-wide full-band gap PnC was designed. The concept of a PnC with an incomplete line defect was proposed. The energy localization and harvesting of incomplete line defect PnCs and traditional point defect and line defect PnCs were studied by finite element analysis. The results show that compared with a point defect and a line defect, the output electric power of an incomplete line defect was increased by 31.88 times and 2.51 times, respectively, and the energy localization and harvesting frequency band were widened. By exploring the influence of the periodicity of the vertical incomplete line defect direction on the electrical output performance of the PnC-based PEH system, it is found that the electrical output performance of the 5 × 3 incomplete line defect PnC is the best, and the maximum output voltage and output electric power are 27.36 V and 17.29 mW, respectively. This work provides new insights and ideas for improving the energy localization and harvesting performance of PnC-based PEH systems.
{"title":"Phononic crystals with incomplete line defects: applications in high-performance and broadband acoustic energy localization and harvesting","authors":"Guo-Yu Zhang, Zi-Jiang Liu, Bing-Zu Li, Xi-Long Dou, Cai-Rong Zhang, Xiao-Wei Sun and Yi-Man Yang","doi":"10.1088/1361-665x/ad649c","DOIUrl":"https://doi.org/10.1088/1361-665x/ad649c","url":null,"abstract":"Using phononic crystals (PnCs) to enhance the electrical output performance of piezoelectric energy harvesting (PEH) devices and broaden the frequency range of harvesting energy is crucial to solving the self-energy of low-power devices such as wireless sensors. In this work, an ultra-wide full-band gap PnC was designed. The concept of a PnC with an incomplete line defect was proposed. The energy localization and harvesting of incomplete line defect PnCs and traditional point defect and line defect PnCs were studied by finite element analysis. The results show that compared with a point defect and a line defect, the output electric power of an incomplete line defect was increased by 31.88 times and 2.51 times, respectively, and the energy localization and harvesting frequency band were widened. By exploring the influence of the periodicity of the vertical incomplete line defect direction on the electrical output performance of the PnC-based PEH system, it is found that the electrical output performance of the 5 × 3 incomplete line defect PnC is the best, and the maximum output voltage and output electric power are 27.36 V and 17.29 mW, respectively. This work provides new insights and ideas for improving the energy localization and harvesting performance of PnC-based PEH systems.","PeriodicalId":21656,"journal":{"name":"Smart Materials and Structures","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141785654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-24DOI: 10.1088/1361-665x/ad6725
Hao Huang, Qingbo He
Electromechanical impedance analysis is a traditional method to identify the occurrence of bolt looseness, but accurate localization of blot looseness is hard to realize on the flange. In this study, a flange model with bolt connection stiffness varying with position is proposed. The location of bolt looseness can be then determined from the impedance spectrum of the model since the uniformity and symmetry of the flange are broken. The analytic model is established to reveal the distinguishability of the eigenfrequency shifting characteristics when the connection stiffness at different positions changes. The frequency shifting sequence is extracted from the coupling impedance spectrum as a feature, and the correlation between the sequences corresponding to bolt looseness at different positions is low. The relationship between the sequence and the degree of looseness is highly related so that the unknown degree of looseness can be matched with the calibrated sequence to realize the localization of the looseness. Based on the distinguishability of the frequency shifting sequence, the connection-stiffness-varying model shows great potential in the field of flanges or other connecting structures for structural health monitoring and damage localization.
{"title":"Bolt looseness localization with connection-stiffness-varying flange","authors":"Hao Huang, Qingbo He","doi":"10.1088/1361-665x/ad6725","DOIUrl":"https://doi.org/10.1088/1361-665x/ad6725","url":null,"abstract":"\u0000 Electromechanical impedance analysis is a traditional method to identify the occurrence of bolt looseness, but accurate localization of blot looseness is hard to realize on the flange. In this study, a flange model with bolt connection stiffness varying with position is proposed. The location of bolt looseness can be then determined from the impedance spectrum of the model since the uniformity and symmetry of the flange are broken. The analytic model is established to reveal the distinguishability of the eigenfrequency shifting characteristics when the connection stiffness at different positions changes. The frequency shifting sequence is extracted from the coupling impedance spectrum as a feature, and the correlation between the sequences corresponding to bolt looseness at different positions is low. The relationship between the sequence and the degree of looseness is highly related so that the unknown degree of looseness can be matched with the calibrated sequence to realize the localization of the looseness. Based on the distinguishability of the frequency shifting sequence, the connection-stiffness-varying model shows great potential in the field of flanges or other connecting structures for structural health monitoring and damage localization.","PeriodicalId":21656,"journal":{"name":"Smart Materials and Structures","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141808449","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-24DOI: 10.1088/1361-665x/ad6739
Arnaud Huijer, Christos Kassapoglou, L. Pahlavan
Flexible composite marine propellers can aid the marine industry in reducing carbon emissions and underwater radiated noise pollution. The structural integrity of the blades can be assessed using structural health monitoring. One of these methods is the measurement and analysis of damage-induced acoustic emission signals. This paper experimentally investigates the feasibility of using embedded piezoelectric sensors for the measurement of acoustic emissions throughout a submerged flexible composite marine propeller blade. A full-scale glass-fibre reinforced polymer blade has been manufactured with 24 embedded sensors. While suspended in artificial seawater, acoustic emissions were simulated on the blade. The measurements show that the embedded piezoelectric sensors can measure acoustic emissions while the blade is submerged. Further, the distance from source to sensor over which the acoustic emission is measurable was investigated. For a noise level of 40dB and a source amplitude of 70dB between 100-250kHz, an average maximum measurable distance of 124mm was obtained. For higher frequencies, the distance drops and for lower noise levels the distance increases.
{"title":"Acoustic emission monitoring of composite marine propellers in submerged conditions using embedded piezoelectric sensors","authors":"Arnaud Huijer, Christos Kassapoglou, L. Pahlavan","doi":"10.1088/1361-665x/ad6739","DOIUrl":"https://doi.org/10.1088/1361-665x/ad6739","url":null,"abstract":"\u0000 Flexible composite marine propellers can aid the marine industry in reducing carbon emissions and underwater radiated noise pollution. The structural integrity of the blades can be assessed using structural health monitoring. One of these methods is the measurement and analysis of damage-induced acoustic emission signals. This paper experimentally investigates the feasibility of using embedded piezoelectric sensors for the measurement of acoustic emissions throughout a submerged flexible composite marine propeller blade. A full-scale glass-fibre reinforced polymer blade has been manufactured with 24 embedded sensors. While suspended in artificial seawater, acoustic emissions were simulated on the blade. The measurements show that the embedded piezoelectric sensors can measure acoustic emissions while the blade is submerged. Further, the distance from source to sensor over which the acoustic emission is measurable was investigated. For a noise level of 40dB and a source amplitude of 70dB between 100-250kHz, an average maximum measurable distance of 124mm was obtained. For higher frequencies, the distance drops and for lower noise levels the distance increases.","PeriodicalId":21656,"journal":{"name":"Smart Materials and Structures","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141806768","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-24DOI: 10.1088/1361-665x/ad63e9
Jiwon Chung, Jeong Eun Yoon, Minseo Kim, Dongjun Shin and Sumin Koo
We developed flexible, lightweight, and washable gloves with actuators to assist finger movements and improve ease of wearing. Performance and wearability were measured using standardized tests, triangulation of bending angles, electromyography (EMG), and grip strength. User satisfaction was measured using a survey. EMG sensors were attached to the flexor digitorum superficialis and extensor digitorum communis to capture movement data for grasping and releasing, lifting and putting down, and opening and closing an object with (a) gloves and an actuator, (b) gloves and no actuator, and (c) no gloves. The actuator-equipped glove weighed 31.4 g—lighter than in any earlier studies. In situation (a), the average EMG values for the four participants decreased, ranging from −2.06% to −44.1%, confirming the superior performance of the gloves. Survey results revealed high levels of user satisfaction. Our study offers insights into the development of rehabilitation robotic gloves that assist muscle movements and are easy to wear.
{"title":"Development of finger movement assistive gloves with pneumatic fabric actuators","authors":"Jiwon Chung, Jeong Eun Yoon, Minseo Kim, Dongjun Shin and Sumin Koo","doi":"10.1088/1361-665x/ad63e9","DOIUrl":"https://doi.org/10.1088/1361-665x/ad63e9","url":null,"abstract":"We developed flexible, lightweight, and washable gloves with actuators to assist finger movements and improve ease of wearing. Performance and wearability were measured using standardized tests, triangulation of bending angles, electromyography (EMG), and grip strength. User satisfaction was measured using a survey. EMG sensors were attached to the flexor digitorum superficialis and extensor digitorum communis to capture movement data for grasping and releasing, lifting and putting down, and opening and closing an object with (a) gloves and an actuator, (b) gloves and no actuator, and (c) no gloves. The actuator-equipped glove weighed 31.4 g—lighter than in any earlier studies. In situation (a), the average EMG values for the four participants decreased, ranging from −2.06% to −44.1%, confirming the superior performance of the gloves. Survey results revealed high levels of user satisfaction. Our study offers insights into the development of rehabilitation robotic gloves that assist muscle movements and are easy to wear.","PeriodicalId":21656,"journal":{"name":"Smart Materials and Structures","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141785581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-24DOI: 10.1088/1361-665x/ad5d33
Manoj Kumar, Keshav Malhotra, Nishu, Rajat Syal, Shailendra Gupta, Gyaneshwar Sharma, Arun Kumar Singh and Sanjeev Kumar
Lead-based ferroelectrics are one of the most fascinating candidates in the field of state-of-the-art electronic technology. Their intriguing properties are further enriched via the realization of morphotropic phase boundaries. Moreover, the A-site chemical substitution provides insight into the emergence of various exotic phases. Here, we employ co-doping of La3+ and Bi3+ at the A-site of Pb(Zr,Ti)O3 (PZT) ferroelectric to broaden the practical perspective of relaxor systems. Here, we emphasize that the A-site co-doping approach introduces technologically appealing amendments in the well-established temperature composition phase diagram of the PZT system. La3+ and Bi3+ doping favors the evolution of a novel response to thermal and field fluctuations. The maximum values of are found to be ∼0.157, 0.118 and 0.176 J (kg·K)−1 for and , respectively. We employ the electrocaloric characteristics and Arrott plot as probing tools. The observation of a negative electrocaloric effect and the systematic reversal of Arrott lines, followed by a poling effect on the dielectric constant, reveals the emergence of ergodic phase as a novel phase. This further reveals that the Bi doping approach leads to the emergence of exotic characteristics in the chemically modified PZT system. The maximum observed recoverable energy for the composition for x = 0.01 is 0.0479 J cm−3 at a temperature of 388 K.
铅基铁电体是最先进电子技术领域最令人着迷的候选材料之一。通过实现形态各向异性相界，它们引人入胜的特性得到了进一步丰富。此外，A-位化学置换还为各种奇异相的出现提供了启示。在这里，我们采用在 Pb（Zr,Ti）O3（PZT）铁电体的 A 位共同掺杂 La3+ 和 Bi3+ 的方法来拓宽弛豫器系统的实用前景。在此，我们强调 A 位共掺方法在 PZT 系统既定的温度成分相图中引入了具有技术吸引力的修正。La3+ 和 Bi3+ 的掺杂有利于对热波动和场波动产生新的响应。我们发现，对于 和 ，其最大值分别为 ∼0.157、0.118 和 0.176 J (kg-K)-1。我们采用电致发热特性和阿罗特曲线图作为探测工具。通过观察负电蚀效应和阿罗特线的系统性反转，以及介电常数的极化效应，我们发现了作为一种新相的麦哲伦相的出现。这进一步表明，掺杂铋的方法导致化学修饰 PZT 系统出现了奇特的特性。在 388 K 的温度下，对 x = 0.01 的成分观察到的最大可恢复能量为 0.0479 J cm-3。
{"title":"Optimization of energy storage and electrocaloric performance in Pb(Zr,Ti)O3 via A-Site La and Bi Co-doping","authors":"Manoj Kumar, Keshav Malhotra, Nishu, Rajat Syal, Shailendra Gupta, Gyaneshwar Sharma, Arun Kumar Singh and Sanjeev Kumar","doi":"10.1088/1361-665x/ad5d33","DOIUrl":"https://doi.org/10.1088/1361-665x/ad5d33","url":null,"abstract":"Lead-based ferroelectrics are one of the most fascinating candidates in the field of state-of-the-art electronic technology. Their intriguing properties are further enriched via the realization of morphotropic phase boundaries. Moreover, the A-site chemical substitution provides insight into the emergence of various exotic phases. Here, we employ co-doping of La3+ and Bi3+ at the A-site of Pb(Zr,Ti)O3 (PZT) ferroelectric to broaden the practical perspective of relaxor systems. Here, we emphasize that the A-site co-doping approach introduces technologically appealing amendments in the well-established temperature composition phase diagram of the PZT system. La3+ and Bi3+ doping favors the evolution of a novel response to thermal and field fluctuations. The maximum values of are found to be ∼0.157, 0.118 and 0.176 J (kg·K)−1 for and , respectively. We employ the electrocaloric characteristics and Arrott plot as probing tools. The observation of a negative electrocaloric effect and the systematic reversal of Arrott lines, followed by a poling effect on the dielectric constant, reveals the emergence of ergodic phase as a novel phase. This further reveals that the Bi doping approach leads to the emergence of exotic characteristics in the chemically modified PZT system. The maximum observed recoverable energy for the composition for x = 0.01 is 0.0479 J cm−3 at a temperature of 388 K.","PeriodicalId":21656,"journal":{"name":"Smart Materials and Structures","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141778950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-24DOI: 10.1088/1361-665x/ad6724
Chao Zhang, Xiaofeng Yin, Rongchu Chen, Kaiwen Ju, Yinxuan Hao, Tong Wu, Jian Sun, Hu xiao Yang, Yan Xu
Bistable structures have attracted attention due to their unique properties and potential applications in soft robotics, logic gates and energy harvesting devices. The bi-stability is always an inherent property if the bistable structures are pre-designed. A reprogrammable bistable structure that does not require re-designing and re-fabricating the prototype is highly desirable. Despite its vast potential and burgeoning interest, the field of reprogrammable bistable structures lacks a cohesive and comprehensive review. Therefore, this paper presents a state-of-the-art review of recent advances in the basic structural forms, key parameters determining bistable characteristics, active regulation mechanisms, and potential applications of reprogrammable bistable structures. It also presents the remaining challenges and suggests possible future research directions in the field of reprogrammable bistable structures. This review will provide valuable insights for researchers and engineers to explore the vast potential of reprogrammable bistable structures.
{"title":"A review on reprogrammable bistable structures","authors":"Chao Zhang, Xiaofeng Yin, Rongchu Chen, Kaiwen Ju, Yinxuan Hao, Tong Wu, Jian Sun, Hu xiao Yang, Yan Xu","doi":"10.1088/1361-665x/ad6724","DOIUrl":"https://doi.org/10.1088/1361-665x/ad6724","url":null,"abstract":"\u0000 Bistable structures have attracted attention due to their unique properties and potential applications in soft robotics, logic gates and energy harvesting devices. The bi-stability is always an inherent property if the bistable structures are pre-designed. A reprogrammable bistable structure that does not require re-designing and re-fabricating the prototype is highly desirable. Despite its vast potential and burgeoning interest, the field of reprogrammable bistable structures lacks a cohesive and comprehensive review. Therefore, this paper presents a state-of-the-art review of recent advances in the basic structural forms, key parameters determining bistable characteristics, active regulation mechanisms, and potential applications of reprogrammable bistable structures. It also presents the remaining challenges and suggests possible future research directions in the field of reprogrammable bistable structures. This review will provide valuable insights for researchers and engineers to explore the vast potential of reprogrammable bistable structures.","PeriodicalId":21656,"journal":{"name":"Smart Materials and Structures","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141806659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-23DOI: 10.1088/1361-665x/ad5bcf
O E Håskjold and L E Helseth
Recent research has shown that it is possible to utilize contact electrification combined with electrostatic induction to harvest electrical energy from the mechanical motion of air bubbles sliding along a charged solid surface immersed in water. The working principle of these devices is simple, but the design is usually complicated as transduction efficiency depends on a number of interdependent parameters. Here we propose a simple analytical model and demonstrate how it can be used to determine the optimal energy per bubble for a given resistive load. The model allows one to estimate the optimal energy harvested per bubble in terms of polymer thickness, electrode separation and load resistance. It is shown that the model provides a good fit to experimental data. The model may be used as an initial step when designing energy harvesting devices utilizing air bubbles sliding along a solid surface.
{"title":"Design of electrical energy harvesting devices utilizing air bubbles sliding along a fluoropolymer immersed in water","authors":"O E Håskjold and L E Helseth","doi":"10.1088/1361-665x/ad5bcf","DOIUrl":"https://doi.org/10.1088/1361-665x/ad5bcf","url":null,"abstract":"Recent research has shown that it is possible to utilize contact electrification combined with electrostatic induction to harvest electrical energy from the mechanical motion of air bubbles sliding along a charged solid surface immersed in water. The working principle of these devices is simple, but the design is usually complicated as transduction efficiency depends on a number of interdependent parameters. Here we propose a simple analytical model and demonstrate how it can be used to determine the optimal energy per bubble for a given resistive load. The model allows one to estimate the optimal energy harvested per bubble in terms of polymer thickness, electrode separation and load resistance. It is shown that the model provides a good fit to experimental data. The model may be used as an initial step when designing energy harvesting devices utilizing air bubbles sliding along a solid surface.","PeriodicalId":21656,"journal":{"name":"Smart Materials and Structures","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141785655","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-23DOI: 10.1088/1361-665x/ad669e
Yunzhi Zhang, J. Ling, Yuchuan Zhu
Piezoelectric stack actuator (PSA) has attracted widespread attention in aerospace applications. However, the severe operating conditions would bring certain risks to PSA, leading to decreased performance or even failure. The conventional PSA structure lacks adaptability in the event of a complete failure occurring within the piezoelectric stack layer (PSL) due to its centralized design and driving method. To address the reliability challenges inherent in PSAs, this paper proposes a novel distributed piezoelectric stack actuator (DPSA) by means of mechanical and electrical dispersion. Additionally, dual-redundant PSLs are integrated into the DPSA as backups, providing hardware redundancy for active Fault-Tolerant Control (FTC). Building upon this foundation, an SMO-based fault detector for DPSA is developed to facilitate fault reconstruction. Subsequently, an active FTC strategy, comprising dual-SMO-based fault detectors and a tracking controller, is introduced to effectively manage faults and reallocate control resources. Comprehensive experiments under various fault scenarios are carried out to assess the performance of the SMO-based fault detector and FTC strategy. The results demonstrate that the proposed fault detector and FTC strategy promptly detect faults and efficiently restore the DPSA to a stable state, thereby ensuring effective trajectory tracking even in the presence of faults.
压电叠层致动器（PSA）在航空航天应用中受到广泛关注。然而，恶劣的工作条件会给 PSA 带来一定的风险，导致性能下降甚至失效。传统的 PSA 结构由于其集中式设计和驱动方法，在压电叠层（PSL）内部发生完全失效时缺乏适应性。为了应对 PSA 固有的可靠性挑战，本文提出了一种新型分布式压电叠层致动器 (DPSA)，通过机械和电气分散的方式来实现。此外，双冗余 PSL 被集成到 DPSA 中作为备份，为主动容错控制（FTC）提供了硬件冗余。在此基础上，为 DPSA 开发了基于 SMO 的故障检测器，以促进故障重建。随后，引入了一种主动 FTC 策略，包括基于 SMO 的双故障检测器和跟踪控制器，以有效管理故障和重新分配控制资源。为了评估基于 SMO 的故障检测器和 FTC 策略的性能，我们在各种故障情况下进行了综合实验。结果表明，所提出的故障检测器和 FTC 策略能及时发现故障，并有效地将 DPSA 恢复到稳定状态，从而确保即使在出现故障的情况下也能进行有效的轨迹跟踪。
{"title":"Development and fault-tolerant control of a distributed piezoelectric stack actuator","authors":"Yunzhi Zhang, J. Ling, Yuchuan Zhu","doi":"10.1088/1361-665x/ad669e","DOIUrl":"https://doi.org/10.1088/1361-665x/ad669e","url":null,"abstract":"\u0000 Piezoelectric stack actuator (PSA) has attracted widespread attention in aerospace applications. However, the severe operating conditions would bring certain risks to PSA, leading to decreased performance or even failure. The conventional PSA structure lacks adaptability in the event of a complete failure occurring within the piezoelectric stack layer (PSL) due to its centralized design and driving method. To address the reliability challenges inherent in PSAs, this paper proposes a novel distributed piezoelectric stack actuator (DPSA) by means of mechanical and electrical dispersion. Additionally, dual-redundant PSLs are integrated into the DPSA as backups, providing hardware redundancy for active Fault-Tolerant Control (FTC). Building upon this foundation, an SMO-based fault detector for DPSA is developed to facilitate fault reconstruction. Subsequently, an active FTC strategy, comprising dual-SMO-based fault detectors and a tracking controller, is introduced to effectively manage faults and reallocate control resources. Comprehensive experiments under various fault scenarios are carried out to assess the performance of the SMO-based fault detector and FTC strategy. The results demonstrate that the proposed fault detector and FTC strategy promptly detect faults and efficiently restore the DPSA to a stable state, thereby ensuring effective trajectory tracking even in the presence of faults.","PeriodicalId":21656,"journal":{"name":"Smart Materials and Structures","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141812899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-22DOI: 10.1088/1361-665x/ad6656
Sherif Okda, Sneha Rupa Nampally, Mauro Fontana, Sven Herold, Rainer Nordmann, Stephan Rinderknecht, Tobias Melz
The efficiency of transmission systems is influenced by the generation of vibrational and acoustic emissions. Lightweight transmission systems are even subjected to higher levels of vibration. In this paper, an economical active vibration control system is developed to control the vibration levels of an automotive gearbox housing. The gearbox's mounting points are targeted to reduce the transmitted vibrations to the car cabin. The active control system aims to target high-frequency vibrations between 1000 Hz and 5000 Hz. A compact piezoelectric inertial mass actuator is designed and tested on a gearbox-constructed setup that simulates the vibrations and noise similar to a commercial automotive transmission system. The developed test-rig is excited by a piezo stack actuator at the input shaft. Filtered-x least mean square algorithm is implemented on a high-speed microcontroller, and the vibration levels are significantly reduced using the active system. An average reduction of approximately 8.5 dB is achieved between 1000 Hz and 1500 Hz, an average reduction of approximately 14 dB is obtained between 1500 and 2000 Hz, and an average reduction of 10.8 dB is attained between 2500 and 5000 Hz.
{"title":"Active vibration control of gearbox housing using inertial mass actuators","authors":"Sherif Okda, Sneha Rupa Nampally, Mauro Fontana, Sven Herold, Rainer Nordmann, Stephan Rinderknecht, Tobias Melz","doi":"10.1088/1361-665x/ad6656","DOIUrl":"https://doi.org/10.1088/1361-665x/ad6656","url":null,"abstract":"\u0000 The efficiency of transmission systems is influenced by the generation of vibrational and acoustic emissions. Lightweight transmission systems are even subjected to higher levels of vibration. In this paper, an economical active vibration control system is developed to control the vibration levels of an automotive gearbox housing. The gearbox's mounting points are targeted to reduce the transmitted vibrations to the car cabin. The active control system aims to target high-frequency vibrations between 1000 Hz and 5000 Hz. A compact piezoelectric inertial mass actuator is designed and tested on a gearbox-constructed setup that simulates the vibrations and noise similar to a commercial automotive transmission system. The developed test-rig is excited by a piezo stack actuator at the input shaft. Filtered-x least mean square algorithm is implemented on a high-speed microcontroller, and the vibration levels are significantly reduced using the active system. An average reduction of approximately 8.5 dB is achieved between 1000 Hz and 1500 Hz, an average reduction of approximately 14 dB is obtained between 1500 and 2000 Hz, and an average reduction of 10.8 dB is attained between 2500 and 5000 Hz.","PeriodicalId":21656,"journal":{"name":"Smart Materials and Structures","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141814512","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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