Pub Date : 2024-09-05DOI: 10.1088/1361-665x/ad742f
Chi Hu, Huoming Shen, Yuxing Wang, Guoyong Zhang, Juan Liu, Xin Zhang
Three-phase smart composites consisting of magnetostrictive and piezoelectric reinforcements embedded with a polymer matrix can achieve specific multifunctional properties in response to external stimuli, which are well-suited for the application of sensors, actuators, and electronic devices. The materials exhibit complex behaviors characterized by electro-magneto-viscoelasticity coupling during the contact of these smart structures. This paper proposes a novel hybrid element method for numerically analyzing the frictionless sliding contact problem stemming from the viscoelastic behavior and multiphase interactions of polymer matrix smart composites. The study aims to fully investigate the effects of material properties, sliding velocities, and action time on the contact behavior of materials via the integration of the conjugate gradient method with the discrete convolution-fast Fourier transform algorithm. The analytical viscoelastic frequency response functions are derived by substituting elastic solutions with the time-dependent relaxation modulus. Numerical results show that three-phase polymer matrix smart composites exhibit lower contact pressure and higher surface electric/magnetic potential than three-phase magneto-electro-elastic composites. Sliding velocity and action time strongly influence the distribution of pressure/stress and electric/magnetic potential.
{"title":"On the time-dependent sliding contact behavior of three-phase polymer matrix smart composites","authors":"Chi Hu, Huoming Shen, Yuxing Wang, Guoyong Zhang, Juan Liu, Xin Zhang","doi":"10.1088/1361-665x/ad742f","DOIUrl":"https://doi.org/10.1088/1361-665x/ad742f","url":null,"abstract":"Three-phase smart composites consisting of magnetostrictive and piezoelectric reinforcements embedded with a polymer matrix can achieve specific multifunctional properties in response to external stimuli, which are well-suited for the application of sensors, actuators, and electronic devices. The materials exhibit complex behaviors characterized by electro-magneto-viscoelasticity coupling during the contact of these smart structures. This paper proposes a novel hybrid element method for numerically analyzing the frictionless sliding contact problem stemming from the viscoelastic behavior and multiphase interactions of polymer matrix smart composites. The study aims to fully investigate the effects of material properties, sliding velocities, and action time on the contact behavior of materials via the integration of the conjugate gradient method with the discrete convolution-fast Fourier transform algorithm. The analytical viscoelastic frequency response functions are derived by substituting elastic solutions with the time-dependent relaxation modulus. Numerical results show that three-phase polymer matrix smart composites exhibit lower contact pressure and higher surface electric/magnetic potential than three-phase magneto-electro-elastic composites. Sliding velocity and action time strongly influence the distribution of pressure/stress and electric/magnetic potential.","PeriodicalId":21656,"journal":{"name":"Smart Materials and Structures","volume":"32 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178659","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 : 2024-09-05DOI: 10.1088/1361-665x/ad74c2
Da Hu, Haotian Long, Jiabin Lu, Huilong Li, Jun Zeng, Qiusheng Yan
By employing magnetorheological elastomers (MREs) as polishing pads for chemical mechanical polishing (CMP), the magnetorheological properties are utilized to effectively control the flexible removal of materials in CMP. This study presents a method for preparing a silicon modified polyurethane (SPU)-based MRE polishing pad, aimed at demonstrating improved magnetorheological properties while preserving mechanical properties. The SPU-based MRE polishing pad was synthesized through the copolymerization of hydroxypropyl silicone oil and polyurethane prepolymers, with subsequent evaluation of its mechanical properties and polishing performance. Fourier transform infrared analysis confirmed the successful incorporation of the soft polydimethylsiloxane main chain from organosilicon into the polyurethane main chain, forming a soft segment that intertwines with the polyurethane main chain to create a soft-hard segment crosslinked structure. Comparison to polyurethane (PU)-based MRE, SPU exhibits significantly reduced hardness but improved wear resistance, as well as enhanced resistance to acid and alkali corrosion. Due to the presence of a soft matrix, SPU shows better magnetorheological effects (MR Effects) than PU-based MRE. Under a magnetic field intensity of 845 mT, the MR Effect of PU-based MRE is only 18%, while Si-15.96 and Si-16.79 SPU-based MREs can reach 84% and 110%, respectively. Although the material removal rate (MRR) of single-crystal SiC decreases after polishing with SPU compared to PU-based MRE, a higher surface quality is achieved, and the glazing degree of the polishing pad is significantly reduced. In the magnetic field-assisted polishing of single crystal SiC, the MRR increased by 38.4% when polished with an SPU-based MRE polishing pad, whereas the MRR was only 8.7% when polished with a PU-based MRE polishing pad. This study provides further evidence for the development and application of MRE in CMP.
{"title":"Preparation and performance study of silicon modified polyurethane-based magnetorheological elastomeric polishing pad","authors":"Da Hu, Haotian Long, Jiabin Lu, Huilong Li, Jun Zeng, Qiusheng Yan","doi":"10.1088/1361-665x/ad74c2","DOIUrl":"https://doi.org/10.1088/1361-665x/ad74c2","url":null,"abstract":"By employing magnetorheological elastomers (MREs) as polishing pads for chemical mechanical polishing (CMP), the magnetorheological properties are utilized to effectively control the flexible removal of materials in CMP. This study presents a method for preparing a silicon modified polyurethane (SPU)-based MRE polishing pad, aimed at demonstrating improved magnetorheological properties while preserving mechanical properties. The SPU-based MRE polishing pad was synthesized through the copolymerization of hydroxypropyl silicone oil and polyurethane prepolymers, with subsequent evaluation of its mechanical properties and polishing performance. Fourier transform infrared analysis confirmed the successful incorporation of the soft polydimethylsiloxane main chain from organosilicon into the polyurethane main chain, forming a soft segment that intertwines with the polyurethane main chain to create a soft-hard segment crosslinked structure. Comparison to polyurethane (PU)-based MRE, SPU exhibits significantly reduced hardness but improved wear resistance, as well as enhanced resistance to acid and alkali corrosion. Due to the presence of a soft matrix, SPU shows better magnetorheological effects (MR Effects) than PU-based MRE. Under a magnetic field intensity of 845 mT, the MR Effect of PU-based MRE is only 18%, while Si-15.96 and Si-16.79 SPU-based MREs can reach 84% and 110%, respectively. Although the material removal rate (MRR) of single-crystal SiC decreases after polishing with SPU compared to PU-based MRE, a higher surface quality is achieved, and the glazing degree of the polishing pad is significantly reduced. In the magnetic field-assisted polishing of single crystal SiC, the MRR increased by 38.4% when polished with an SPU-based MRE polishing pad, whereas the MRR was only 8.7% when polished with a PU-based MRE polishing pad. This study provides further evidence for the development and application of MRE in CMP.","PeriodicalId":21656,"journal":{"name":"Smart Materials and Structures","volume":"14 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178660","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}
Accurate and fast prediction of structural response under seismic action is important for structural performance assessment, however, existing deep learning-based prediction methods do not consider the effect of pulse characteristics of near-fault pulse-like ground motions on structural response. To address the above issues, a new method based on wavelet decomposition and attention mechanism-enhanced decomposition learning, i.e. WD–AttDL, is proposed in this study to predict structural response under pulse-like ground motions. This method innovatively combines a WD-based velocity pulse-identification method with decomposition learning, where decomposed pulses and high-frequency features are used as inputs to the neural-network model, thus simplifying the identification of pulse features for the model. The decomposition learning model integrates several types of neural network components such as convolutional neural network feature extraction submodule, long short-term memory neural network temporal learning submodule and self-attention mechanism submodule. In order to verify the accuracy and validity of the proposed methodology, three sets of case studies were carried out, including elasto-plastic time-history analyses of planar reinforced concrete (RC) frame structures, a three-dimensional RC frame structure, and two types of masonry seismic isolation structures. Compared with existing structural seismic response models, WD–AttDL synergistically integrates the advantages of different modules and thus offers a higher prediction accuracy. In particular, it reduces the peak error of the predicted response, which is important for the evaluation of structural performance. In addition, WD–AttDL has a great potential for application in fast vulnerability and reliability analysis of pulse-like earthquakes in nonlinear structures.
{"title":"A nonlinear structural pulse-like seismic response prediction method based on pulse-like identification and decomposition learning","authors":"Bo Liu, Qiang Xu, Jianyun Chen, Yin Wang, Jiansheng Chen, Tianran Zhang","doi":"10.1088/1361-665x/ad742d","DOIUrl":"https://doi.org/10.1088/1361-665x/ad742d","url":null,"abstract":"Accurate and fast prediction of structural response under seismic action is important for structural performance assessment, however, existing deep learning-based prediction methods do not consider the effect of pulse characteristics of near-fault pulse-like ground motions on structural response. To address the above issues, a new method based on wavelet decomposition and attention mechanism-enhanced decomposition learning, i.e. WD–AttDL, is proposed in this study to predict structural response under pulse-like ground motions. This method innovatively combines a WD-based velocity pulse-identification method with decomposition learning, where decomposed pulses and high-frequency features are used as inputs to the neural-network model, thus simplifying the identification of pulse features for the model. The decomposition learning model integrates several types of neural network components such as convolutional neural network feature extraction submodule, long short-term memory neural network temporal learning submodule and self-attention mechanism submodule. In order to verify the accuracy and validity of the proposed methodology, three sets of case studies were carried out, including elasto-plastic time-history analyses of planar reinforced concrete (RC) frame structures, a three-dimensional RC frame structure, and two types of masonry seismic isolation structures. Compared with existing structural seismic response models, WD–AttDL synergistically integrates the advantages of different modules and thus offers a higher prediction accuracy. In particular, it reduces the peak error of the predicted response, which is important for the evaluation of structural performance. In addition, WD–AttDL has a great potential for application in fast vulnerability and reliability analysis of pulse-like earthquakes in nonlinear structures.","PeriodicalId":21656,"journal":{"name":"Smart Materials and Structures","volume":"60 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178656","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 : 2024-09-05DOI: 10.1088/1361-665x/ad70e4
Aamna Hameed, Kamran A Khan
It remains a challenge to develop an intelligent, programmable multifunctional material system capable of recovering shape, withstanding high loads, and detecting folding extent remotely for self-deployable structures used in aerospace, robotics, and medical devices. In this work, our objective is to develop intelligent shape memory polymer composite (iSMPC) folds embedded with reduced graphene oxide-coated self-sensing fabric. This will enable remote sensing of the fold state based on resistance changes and achieve higher strength and modulus. Firstly, we demonstrate the ability to sense the extent of folding and establish the relationship between piezoresistivity and fold state change by conducting cyclic compression analysis on folds with different gap sizes (6 mm, 9 mm, and 12 mm) at temperatures of 25 °C, 35 °C, and 45 °C. The iSMPC fold with a 6 mm gap exhibited the highest bending stiffness (650.3 N mm−1) and curvature (0.55 mm−1), resulting in a higher change in fractional change in resistance (FCR). Subsequently, the shape memory cycles of the 6 mm iSMPC fold were demonstrated through localized controlled heating. Its shape recovery process exhibited repeatable behavior with a high recovery ratio of 95%. Lastly, a two-fold iSMPC structure was developed, and its performance was analyzed during a complete shape memory cycle. The piezoresistive response during higher-temperature cyclic loading resembled that of the single fold, exhibiting an FCR range between −9% and 5%, thereby demonstrating the repeatability of the iSMPC fold response.
{"title":"Origami inspired dual matrix intelligent shape memory polymer composite folds for deployable structures","authors":"Aamna Hameed, Kamran A Khan","doi":"10.1088/1361-665x/ad70e4","DOIUrl":"https://doi.org/10.1088/1361-665x/ad70e4","url":null,"abstract":"It remains a challenge to develop an intelligent, programmable multifunctional material system capable of recovering shape, withstanding high loads, and detecting folding extent remotely for self-deployable structures used in aerospace, robotics, and medical devices. In this work, our objective is to develop intelligent shape memory polymer composite (iSMPC) folds embedded with reduced graphene oxide-coated self-sensing fabric. This will enable remote sensing of the fold state based on resistance changes and achieve higher strength and modulus. Firstly, we demonstrate the ability to sense the extent of folding and establish the relationship between piezoresistivity and fold state change by conducting cyclic compression analysis on folds with different gap sizes (6 mm, 9 mm, and 12 mm) at temperatures of 25 °C, 35 °C, and 45 °C. The iSMPC fold with a 6 mm gap exhibited the highest bending stiffness (650.3 N mm<sup>−1</sup>) and curvature (0.55 mm<sup>−1</sup>), resulting in a higher change in fractional change in resistance (FCR). Subsequently, the shape memory cycles of the 6 mm iSMPC fold were demonstrated through localized controlled heating. Its shape recovery process exhibited repeatable behavior with a high recovery ratio of 95%. Lastly, a two-fold iSMPC structure was developed, and its performance was analyzed during a complete shape memory cycle. The piezoresistive response during higher-temperature cyclic loading resembled that of the single fold, exhibiting an FCR range between −9% and 5%, thereby demonstrating the repeatability of the iSMPC fold response.","PeriodicalId":21656,"journal":{"name":"Smart Materials and Structures","volume":"152 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178654","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 : 2024-09-05DOI: 10.1088/1361-665x/ad72bf
Mansour Abdelrahman, Chengliang Fan, Minyi Yi, Zutao Zhang, Asif Ali, Xiaofeng Xia, A A Mohamed, Shoukat Ali Mugheri, Ammar Ahmed
In recent years, the increasing adoption of electric buses (EBs) worldwide has contributed significantly to reducing environmental pollution. Nevertheless, the most challenging obstacle hindering the efficiency of EBs is their power supply. In this study, a multi-purpose variable damping energy regenerative damper (VD-ERD) using a double coaxial slotted link motion conversion mechanism was proposed for health monitoring of the EBs suspension system, tunning the damping during the operation on different road conditions while providing electric energy for self-powered sensors in EBs. The VD-ERD consists of two identical generators; one is connected to optimal constant resistance for maximum energy harvesting, and the other is linked to adjustable resistance for fine-tuning the damping. Consequently, both generators connect to a rectifier and storage circuits. Furthermore, VD-ERD was developed in MATLAB/Simulink to evaluate its performance in damping and energy harvesting in different road excitations. The VD-ERD achieved an 11.59 W peak and 1.84 W RMS power at 50 km h−1 on an ISO class A road and a 36.38 W peak and 6.34 W RMS power on an ISO class B road. In addition, the experimental finding indicated that controlling the external resistance is capable of tuning the damping. Simultaneously, the prototype achieved a peak power output of 10.29 W at 12 mm and 3 Hz. Furthermore, the voltage signals received from the generators were analyzed using a deep learning model to monitor the condition of the suspension system in four different modes, namely slow, medium, fast, and failure; the result shows 99.37% training accuracy. Feasibility analysis and performance testing showed that VD-ERD provides sufficient power to 10 sensors, indicating that it can power the self-powered and self-sensing devices of EBs.
近年来，电动公交车（EB）在全球范围内的应用日益广泛，为减少环境污染做出了巨大贡献。然而，妨碍电动公交车效率的最大障碍是其电力供应。本研究提出了一种多用途可变阻尼能量再生阻尼器（VD-ERD），它采用双同轴开槽连杆运动转换机制，用于监测电动公交车悬挂系统的健康状况，在不同路况下运行时调节阻尼，同时为电动公交车中的自供电传感器提供电能。VD-ERD 由两个相同的发电机组成；其中一个与最佳恒定电阻相连，用于最大限度地收集能量；另一个与可调电阻相连，用于微调阻尼。因此，两个发电机都与整流器和存储电路相连。此外，VD-ERD 是在 MATLAB/Simulink 中开发的，用于评估其在不同道路激励下的阻尼和能量收集性能。VD-ERD 在 50 km h-1 的 ISO A 级道路上实现了 11.59 W 的峰值功率和 1.84 W 的有效值功率，在 ISO B 级道路上实现了 36.38 W 的峰值功率和 6.34 W 的有效值功率。此外，实验结果表明，控制外部电阻能够调整阻尼。同时，原型在 12 毫米和 3 赫兹频率下实现了 10.29 瓦的峰值功率输出。此外，还利用深度学习模型分析了从发电机接收到的电压信号，以监测悬挂系统在四种不同模式（即慢速、中速、快速和失效）下的状况；结果显示训练准确率为 99.37%。可行性分析和性能测试表明，VD-ERD 可为 10 个传感器提供足够的电力，这表明它可以为 EB 的自供电和自传感设备供电。
{"title":"Variable damping energy regenerative damper for self-powered sensors and self-sensing devices in smart electric buses","authors":"Mansour Abdelrahman, Chengliang Fan, Minyi Yi, Zutao Zhang, Asif Ali, Xiaofeng Xia, A A Mohamed, Shoukat Ali Mugheri, Ammar Ahmed","doi":"10.1088/1361-665x/ad72bf","DOIUrl":"https://doi.org/10.1088/1361-665x/ad72bf","url":null,"abstract":"In recent years, the increasing adoption of electric buses (EBs) worldwide has contributed significantly to reducing environmental pollution. Nevertheless, the most challenging obstacle hindering the efficiency of EBs is their power supply. In this study, a multi-purpose variable damping energy regenerative damper (VD-ERD) using a double coaxial slotted link motion conversion mechanism was proposed for health monitoring of the EBs suspension system, tunning the damping during the operation on different road conditions while providing electric energy for self-powered sensors in EBs. The VD-ERD consists of two identical generators; one is connected to optimal constant resistance for maximum energy harvesting, and the other is linked to adjustable resistance for fine-tuning the damping. Consequently, both generators connect to a rectifier and storage circuits. Furthermore, VD-ERD was developed in MATLAB/Simulink to evaluate its performance in damping and energy harvesting in different road excitations. The VD-ERD achieved an 11.59 W peak and 1.84 W RMS power at 50 km h<sup>−1</sup> on an ISO class A road and a 36.38 W peak and 6.34 W RMS power on an ISO class B road. In addition, the experimental finding indicated that controlling the external resistance is capable of tuning the damping. Simultaneously, the prototype achieved a peak power output of 10.29 W at 12 mm and 3 Hz. Furthermore, the voltage signals received from the generators were analyzed using a deep learning model to monitor the condition of the suspension system in four different modes, namely slow, medium, fast, and failure; the result shows 99.37% training accuracy. Feasibility analysis and performance testing showed that VD-ERD provides sufficient power to 10 sensors, indicating that it can power the self-powered and self-sensing devices of EBs.","PeriodicalId":21656,"journal":{"name":"Smart Materials and Structures","volume":"11 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178655","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}
Ultrasonic guided wave (UGW) has a wide monitoring range and high accuracy, showing promise for monitoring damage in large-area composite fan blades. However, the multi-curvature characteristics of engine composite fan blades and their anisotropic material properties make damage localization difficult with conventional UGW monitoring methods. In order to realize the UGW damage monitoring of the blade, this paper proposes a damage localization method based on damage-scattered wave differences. This method addresses the challenge of locating damage in multi-curvature composite blades. First, the difference between the mutual excitation in a pair of sensors and the damage-scattered waves captured at reception was analyzed. It is concluded that the closer the damage is to the receiving sensor, the greater the damage index (DI). Next, a DI ratio of the mutually excited and received signals is computed for each sensor pair. This ratio is used to draw a vertical line on the propagation path, identified as the damage likelihood line (DLL). Finally, the DLL corresponding to the three largest DIs is selected, and their intersections were used for damage localization. A time-domain truncated signal processing method is proposed to enable the DI to more accurately represent the effects of damage and improve the localization accuracy of the method. An experiment on damage localization was conducted on a homemade composite fan blade, where the damage was tested at various locations and sizes. The results show that the damage localization on the blade is good and 3 mm tiny damage localization is achieved.
超声波导波（UGW）监测范围广、精度高，有望监测大面积复合材料风扇叶片的损坏情况。然而，发动机复合材料风扇叶片的多曲率特征及其各向异性的材料特性，使得传统的 UGW 监测方法难以实现损伤定位。为了实现叶片的 UGW 损伤监测，本文提出了一种基于损伤散射波差异的损伤定位方法。该方法解决了多曲率复合材料叶片损伤定位的难题。首先，分析了一对传感器中的相互激励与接收时捕获的损伤散射波之间的差异。结论是，损伤越靠近接收传感器，损伤指数（DI）就越大。接下来，计算每对传感器的互激信号和接收信号的损伤指数比。利用这一比率在传播路径上画出一条垂直线，即损伤似然线（DLL）。最后，选择与三个最大 DI 相对应的 DLL，并利用它们的交点进行损伤定位。提出了一种时域截断信号处理方法，使 DI 能够更准确地表示损伤的影响，并提高该方法的定位精度。在自制的复合材料风扇叶片上进行了损伤定位实验，测试了不同位置和大小的损伤。结果表明，叶片上的损伤定位效果良好，实现了 3 毫米的微小损伤定位。
{"title":"Ultrasonic guided wave damage localization method for composite fan blades based on damage-scattered wave difference","authors":"Hailong Liu, Meiao Huang, Qingchen Zhang, Qijian Liu, Yishou Wang, Xinlin Qing","doi":"10.1088/1361-665x/ad742e","DOIUrl":"https://doi.org/10.1088/1361-665x/ad742e","url":null,"abstract":"Ultrasonic guided wave (UGW) has a wide monitoring range and high accuracy, showing promise for monitoring damage in large-area composite fan blades. However, the multi-curvature characteristics of engine composite fan blades and their anisotropic material properties make damage localization difficult with conventional UGW monitoring methods. In order to realize the UGW damage monitoring of the blade, this paper proposes a damage localization method based on damage-scattered wave differences. This method addresses the challenge of locating damage in multi-curvature composite blades. First, the difference between the mutual excitation in a pair of sensors and the damage-scattered waves captured at reception was analyzed. It is concluded that the closer the damage is to the receiving sensor, the greater the damage index (DI). Next, a DI ratio of the mutually excited and received signals is computed for each sensor pair. This ratio is used to draw a vertical line on the propagation path, identified as the damage likelihood line (DLL). Finally, the DLL corresponding to the three largest DIs is selected, and their intersections were used for damage localization. A time-domain truncated signal processing method is proposed to enable the DI to more accurately represent the effects of damage and improve the localization accuracy of the method. An experiment on damage localization was conducted on a homemade composite fan blade, where the damage was tested at various locations and sizes. The results show that the damage localization on the blade is good and 3 mm tiny damage localization is achieved.","PeriodicalId":21656,"journal":{"name":"Smart Materials and Structures","volume":"17 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178657","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 : 2024-09-05DOI: 10.1088/1361-665x/ad7430
Shreya Shukla, Sanjeev A Sahu
This paper investigates the propagation of horizontally polarized shear waves in a piezoelectric semiconductor (PSC) layered structure. The modal consists of a pre-stressed PSC thin plate atop an elastic dielectric half-space joined perfectly at the interface. It is postulated that the material parameters and initial stress exhibit an exponential variation exclusively along the depth. The velocity equation of the considered wave is analytically obtained based on the traction-free boundary conditions. Numerical examples have been employed to examine the influences of several parameters, including semiconducting properties, material gradient index, initial stresses, external biasing electric field, and PSC film thickness, on the characteristics of the wave. Graphs have been generated to visualize the dependency of wave velocity and attenuation on these factors. The wave’s velocity and damping properties are significantly influenced by the thickness and steady state carrier density of the PSC plate. Besides yielding critical results, current findings are instrumental in designing high-frequency SAW devices.
{"title":"Shear wave velocity in a functionally graded piezoelectric semiconductor plate clamped on a rigid base","authors":"Shreya Shukla, Sanjeev A Sahu","doi":"10.1088/1361-665x/ad7430","DOIUrl":"https://doi.org/10.1088/1361-665x/ad7430","url":null,"abstract":"This paper investigates the propagation of horizontally polarized shear waves in a piezoelectric semiconductor (PSC) layered structure. The modal consists of a pre-stressed PSC thin plate atop an elastic dielectric half-space joined perfectly at the interface. It is postulated that the material parameters and initial stress exhibit an exponential variation exclusively along the depth. The velocity equation of the considered wave is analytically obtained based on the traction-free boundary conditions. Numerical examples have been employed to examine the influences of several parameters, including semiconducting properties, material gradient index, initial stresses, external biasing electric field, and PSC film thickness, on the characteristics of the wave. Graphs have been generated to visualize the dependency of wave velocity and attenuation on these factors. The wave’s velocity and damping properties are significantly influenced by the thickness and steady state carrier density of the PSC plate. Besides yielding critical results, current findings are instrumental in designing high-frequency SAW devices.","PeriodicalId":21656,"journal":{"name":"Smart Materials and Structures","volume":"6 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178658","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 : 2024-09-04DOI: 10.1088/1361-665x/ad7213
Young Bin Kim, Heechan Song, Suji Kim, Heoung-Jae Chun
This study focuses on the 4D printing simulation technique of magneto-responsive shape memory nanocomposite stents. A nanocomposite material was created by incorporating polycaprolactone, a shape memory material, with Fe3O4 to enhance magnetic responsiveness and stiffness. Tensile tests were conducted, and the material properties were applied to finite element analysis. Shape memory experiments were also performed to measure the temperature at which shape memory progression occurs due to magnetic response. In the 4D printing simulation, different coefficients of thermal expansion and the measured temperatures were reflected in the sections where shape memory is activated to implement shape memory behavior. The specimen simulation confirmed shape memory behavior progressing from 145 degrees to 3 degrees, while the stent simulation demonstrated satisfactory expansion to a radius of 3 mm. This study proposes a controllable method for implementing shape memory considering temperatures induced by magnetic response, showing potential for various medical device applications.
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The classic vibration energy collector has functional restrictions, and it can only collect vibration energy in one or two dimensions. At the same time, it has issues with low output power in the low-frequency vibration region and a limited reaction frequency range. This research proposes a segmented nonlinear broadband piezoelectric–magnetic coupled energy collector capable of collecting vibration energy in different directions. The collector is equivalent to current state-of-the-art research in that it can collect vibration energy in three dimensions while also having a wide collection frequency and a high power density. The collection consists of a hemispherical support structure and four fundamental piezoelectric beam collision components. The rationality of the collision segmentation nonlinear principle is first clarified through theoretical calculation and analysis, and then the collision design is applied between the ends of different cantilever beams to broaden the captured energy frequency band, while parallel piezoelectric beams use a 45° tilt treatment to fully utilize the geometrical properties of the tilted beams for multidirectional energy collection. In addition, the collector introduces a magnetic coupling effect to create a bistable structure via magnetic contact. Comsol 5.6 software is used to model and simulate the planned 45° tilted beam structure, which clarifies the piezoelectric beam’s linear intrinsic frequency characteristics and multi-directional geometric aspects. To further verify the collector’s validity, a physical model is built and a vibration experiment apparatus is created. The experimental results demonstrate that the collector’s effective bandwidth range is up to 6.3 Hz under 1 g acceleration excitation, representing a 125.0% increase in bandwidth when compared to the cantilever beam with a linear array. At 14 Hz frequency, the collector produces a maximum total output power of 19.52 mW and a power density of up to 3211uW cm−3 when excitation is provided in the Z-direction.
{"title":"A sectional nonlinear wideband piezoelectric-magnetic coupled energy collector for collecting multi-directional vibrational energy","authors":"Yuancheng Zhu, Yongqiang Zhu, Longhua Zou, Han Chi, Huyue Zhuang, Pingxia Zhang","doi":"10.1088/1361-665x/ad7214","DOIUrl":"https://doi.org/10.1088/1361-665x/ad7214","url":null,"abstract":"The classic vibration energy collector has functional restrictions, and it can only collect vibration energy in one or two dimensions. At the same time, it has issues with low output power in the low-frequency vibration region and a limited reaction frequency range. This research proposes a segmented nonlinear broadband piezoelectric–magnetic coupled energy collector capable of collecting vibration energy in different directions. The collector is equivalent to current state-of-the-art research in that it can collect vibration energy in three dimensions while also having a wide collection frequency and a high power density. The collection consists of a hemispherical support structure and four fundamental piezoelectric beam collision components. The rationality of the collision segmentation nonlinear principle is first clarified through theoretical calculation and analysis, and then the collision design is applied between the ends of different cantilever beams to broaden the captured energy frequency band, while parallel piezoelectric beams use a 45° tilt treatment to fully utilize the geometrical properties of the tilted beams for multidirectional energy collection. In addition, the collector introduces a magnetic coupling effect to create a bistable structure via magnetic contact. Comsol 5.6 software is used to model and simulate the planned 45° tilted beam structure, which clarifies the piezoelectric beam’s linear intrinsic frequency characteristics and multi-directional geometric aspects. To further verify the collector’s validity, a physical model is built and a vibration experiment apparatus is created. The experimental results demonstrate that the collector’s effective bandwidth range is up to 6.3 Hz under 1 g acceleration excitation, representing a 125.0% increase in bandwidth when compared to the cantilever beam with a linear array. At 14 Hz frequency, the collector produces a maximum total output power of 19.52 mW and a power density of up to 3211uW cm<sup>−3</sup> when excitation is provided in the <italic toggle=\"yes\">Z</italic>-direction.","PeriodicalId":21656,"journal":{"name":"Smart Materials and Structures","volume":"9 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142223638","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 : 2024-09-03DOI: 10.1088/1361-665x/ad6ece
M Ali Taşkıran, M Bülent Özer
Piezoelectric vibration isolation and energy harvesting applications have been extensively studied in the literature. The studies include linear and nonlinear approaches. Linear methods are simpler but possess inherent limitations. On the other hand, nonlinear ones could perform better over a broader operating frequency range. Nonlinearity can be introduced in the mechanical domain or electrical domain actively or passively. Since electrical components can be on smaller scales compared to mechanical counterparts, inducing nonlinearity on the mechanical system through the electrical domain can be more practical. Moreover, passive structures require no energy supply and controller therefore they are simpler and more reliable than active ones. In this paper, a novel way to attain passive hardening stiffness was suggested by introducing an electrical component in a shunt circuit for passive nonlinear piezoelectric vibration isolation or energy harvesting applications and the induced structural non-linearity is demonstrated experimentally. A passive nonlinear component is suggested to be a hardening capacitor obtained by the P–N junction. An analytic model is derived for parallel connected macro-fiber composite (MFC) piezoelectric material attached bimorph configuration on a cantilever beam and the model is solved numerically. MFC integrated bimorph model, and P–N junction approximate model are presented. The frequency response of the coupled system is obtained by using numerical models and experiments. Both numerical analysis and experiments validated the hardening stiffness effect of the P–N junction. To the best of the authors’ knowledge, this study is the first study to demonstrate that nonlinear capacitance of P–N junctions can be used to attain nonlinearity in a mechanical system.
{"title":"Experimentally validated passive nonlinear capacitor in piezoelectric vibration applications","authors":"M Ali Taşkıran, M Bülent Özer","doi":"10.1088/1361-665x/ad6ece","DOIUrl":"https://doi.org/10.1088/1361-665x/ad6ece","url":null,"abstract":"Piezoelectric vibration isolation and energy harvesting applications have been extensively studied in the literature. The studies include linear and nonlinear approaches. Linear methods are simpler but possess inherent limitations. On the other hand, nonlinear ones could perform better over a broader operating frequency range. Nonlinearity can be introduced in the mechanical domain or electrical domain actively or passively. Since electrical components can be on smaller scales compared to mechanical counterparts, inducing nonlinearity on the mechanical system through the electrical domain can be more practical. Moreover, passive structures require no energy supply and controller therefore they are simpler and more reliable than active ones. In this paper, a novel way to attain passive hardening stiffness was suggested by introducing an electrical component in a shunt circuit for passive nonlinear piezoelectric vibration isolation or energy harvesting applications and the induced structural non-linearity is demonstrated experimentally. A passive nonlinear component is suggested to be a hardening capacitor obtained by the P–N junction. An analytic model is derived for parallel connected macro-fiber composite (MFC) piezoelectric material attached bimorph configuration on a cantilever beam and the model is solved numerically. MFC integrated bimorph model, and P–N junction approximate model are presented. The frequency response of the coupled system is obtained by using numerical models and experiments. Both numerical analysis and experiments validated the hardening stiffness effect of the P–N junction. To the best of the authors’ knowledge, this study is the first study to demonstrate that nonlinear capacitance of P–N junctions can be used to attain nonlinearity in a mechanical system.","PeriodicalId":21656,"journal":{"name":"Smart Materials and Structures","volume":"11 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178675","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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