Pub Date : 2021-08-01DOI: 10.12989/SSS.2021.28.2.195
Zeinab Soleimani-Javid, S. Amir, Z. K. Maraghi
Free vibration analysis of a sandwich beam with honeycomb core and piezoelectric face sheets, which is rested on the viscoelastic foundation is investigated. The thermal environment and the electric field are applied to this structure. Also, it is affected by the proportional-derivative (PD) controller. The amount of gain in this controller can affects the vibration frequency. The displacement components are expressed by improved high-order sandwich panel theory (IHSAPT) that considers continuity conditions for transverse shear stress at the interfaces and the zero transverse shear stresses conditions on the upper and lower surfaces of the beam and core flexibility. The motion equations are derived and solved by Hamilton's principle and Navier's method, respectively. This paper examines the effects of various parameters, such as the internal aspect ratio and the cell angle/thickness of the honeycomb core, temperature variations, viscoelastic environment, electric load, and control gain on its natural frequencies. The results show when the honeycomb core's to face sheet's thickness ratio increases, the beam dimensionless frequency increases, too. Also, by increasing the internal aspect ratio of honeycomb core, the frequency of sandwich beam decreases. The results of this study can be used to vibration control in aerospace engineering and constructions.
{"title":"Vibration analysis of sandwich beam with honeycomb core and piezoelectric facesheets affected by PD controller","authors":"Zeinab Soleimani-Javid, S. Amir, Z. K. Maraghi","doi":"10.12989/SSS.2021.28.2.195","DOIUrl":"https://doi.org/10.12989/SSS.2021.28.2.195","url":null,"abstract":"Free vibration analysis of a sandwich beam with honeycomb core and piezoelectric face sheets, which is rested on the viscoelastic foundation is investigated. The thermal environment and the electric field are applied to this structure. Also, it is affected by the proportional-derivative (PD) controller. The amount of gain in this controller can affects the vibration frequency. The displacement components are expressed by improved high-order sandwich panel theory (IHSAPT) that considers continuity conditions for transverse shear stress at the interfaces and the zero transverse shear stresses conditions on the upper and lower surfaces of the beam and core flexibility. The motion equations are derived and solved by Hamilton's principle and Navier's method, respectively. This paper examines the effects of various parameters, such as the internal aspect ratio and the cell angle/thickness of the honeycomb core, temperature variations, viscoelastic environment, electric load, and control gain on its natural frequencies. The results show when the honeycomb core's to face sheet's thickness ratio increases, the beam dimensionless frequency increases, too. Also, by increasing the internal aspect ratio of honeycomb core, the frequency of sandwich beam decreases. The results of this study can be used to vibration control in aerospace engineering and constructions.","PeriodicalId":51155,"journal":{"name":"Smart Structures and Systems","volume":"28 1","pages":"195"},"PeriodicalIF":3.5,"publicationDate":"2021-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41708972","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-01DOI: 10.12989/SSS.2021.28.2.153
Shiren O. Muhammad, N. A. Hussain
This paper presents new parameters for damping improvement in F2MC tubes performance as tunable vibration absorbers. They offer very good performance with environments having susceptibility to high frequency vibration noise. This study highlights the behavior of changing some parameters of F2MC tubes which never have been studied before. These parameters include thickness ratio between each two respective layers and fluid type that the tubes are filled with. In this paper the beam governing equations with the tube's stress analyses equations are solved for finding the combined system's response by MATLAB® software function solvers. To ensure accuracy of modifications, validations have been proposed by performing illustrative examples and comparing the results with the existing data available in literature. The results showed improvements of F2MC tubes performance 20% over previous studies achievements by studying the thickness ratio, and another 12.82% can be added by using glycerin instead of water under the same conditions. Finally, the reduction of 34.34 dB in first mode amplitude of vibration was achieved in the beam's frequency response function plot.
{"title":"Modifications on F 2 MC tubes as passive tunable vibration absorbers","authors":"Shiren O. Muhammad, N. A. Hussain","doi":"10.12989/SSS.2021.28.2.153","DOIUrl":"https://doi.org/10.12989/SSS.2021.28.2.153","url":null,"abstract":"This paper presents new parameters for damping improvement in F2MC tubes performance as tunable vibration absorbers. They offer very good performance with environments having susceptibility to high frequency vibration noise. This study highlights the behavior of changing some parameters of F2MC tubes which never have been studied before. These parameters include thickness ratio between each two respective layers and fluid type that the tubes are filled with. In this paper the beam governing equations with the tube's stress analyses equations are solved for finding the combined system's response by MATLAB® software function solvers. To ensure accuracy of modifications, validations have been proposed by performing illustrative examples and comparing the results with the existing data available in literature. The results showed improvements of F2MC tubes performance 20% over previous studies achievements by studying the thickness ratio, and another 12.82% can be added by using glycerin instead of water under the same conditions. Finally, the reduction of 34.34 dB in first mode amplitude of vibration was achieved in the beam's frequency response function plot.","PeriodicalId":51155,"journal":{"name":"Smart Structures and Systems","volume":"28 1","pages":"153"},"PeriodicalIF":3.5,"publicationDate":"2021-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49335691","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-01DOI: 10.12989/SSS.2021.28.2.245
Qingjun Chen, Zhipeng Zhao, Zhang Ruifu
Because of the limited land resources and preference of centralized services, more structures are often built close to each other, correspondingly yielding a demand that mitigates the dynamic responses of adjacent structures. Utilizing the intrinsic potential of the inerter to improve structural energy performances, an inerter-system chain is proposed for the adjacent singledegree-of-freedom structures, which forms a novel configuration featuring the reduction in input energy transmitted to the adjacent structures. The inerter-system chain is realized by two end-placed inerter-dashpot dampers and inter-placed springinerter-dashpot elements arranged in parallel. Stochastic energy balance analysis is conducted to derive a closed-form energy equation that reveals the energy basis of the inerter-system chain. An energy-based and bi-objective optimization strategy is developed with simultaneous consideration of displacement and energy performances, particularly easy-to-use design formulae being derived. The findings of this study show that a complete inerter-system chain exhibits a significant multi-reduction in the structural displacement, shear force, and dissipation energy burden. Particularly, the effectiveness of reducing the input power and vibrational energy transmitted into the entire structures counts on the series inerter-chain, which differentiates the proposed chain from alternative layouts. The proposed energy-based design framework is capable of minimizing the energy dissipation cost, with target displacement control demand satisfied.
{"title":"An inerter-system chain and energy-based optimal control of adjacent single-degree-of-freedom structures","authors":"Qingjun Chen, Zhipeng Zhao, Zhang Ruifu","doi":"10.12989/SSS.2021.28.2.245","DOIUrl":"https://doi.org/10.12989/SSS.2021.28.2.245","url":null,"abstract":"Because of the limited land resources and preference of centralized services, more structures are often built close to each other, correspondingly yielding a demand that mitigates the dynamic responses of adjacent structures. Utilizing the intrinsic potential of the inerter to improve structural energy performances, an inerter-system chain is proposed for the adjacent singledegree-of-freedom structures, which forms a novel configuration featuring the reduction in input energy transmitted to the adjacent structures. The inerter-system chain is realized by two end-placed inerter-dashpot dampers and inter-placed springinerter-dashpot elements arranged in parallel. Stochastic energy balance analysis is conducted to derive a closed-form energy equation that reveals the energy basis of the inerter-system chain. An energy-based and bi-objective optimization strategy is developed with simultaneous consideration of displacement and energy performances, particularly easy-to-use design formulae being derived. The findings of this study show that a complete inerter-system chain exhibits a significant multi-reduction in the structural displacement, shear force, and dissipation energy burden. Particularly, the effectiveness of reducing the input power and vibrational energy transmitted into the entire structures counts on the series inerter-chain, which differentiates the proposed chain from alternative layouts. The proposed energy-based design framework is capable of minimizing the energy dissipation cost, with target displacement control demand satisfied.","PeriodicalId":51155,"journal":{"name":"Smart Structures and Systems","volume":"28 1","pages":"245"},"PeriodicalIF":3.5,"publicationDate":"2021-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48681671","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-01DOI: 10.12989/SSS.2021.28.2.167
Chao Liu, Y. Zandi, Abouzar Rahimi, Yongli Peng, G. Ge, M. Khadimallah, A. Issakhov, Subbotina Tatyana Yu
Shear connectors play a major role in the development of composite steel concrete systems. The behavior of shear connectors is usually calculated by push-out measurements. These experiments are expensive and take a lot of time. Soft Computation (SC) may be applied as an additional solution to remove the need for push-out testing. The objective of the research is to explore the implementation, as sub-branches of the SC approaches, of artificial intelligence (AI) techniques for the prediction of advanced C-shaped shear connectors. To this end, multiple push-out tests on these connectors will be carried out and the requisite data is obtained for the AI models. The Grey Wolf Optimizer algorithm (GWO) is built to define the parameters that influence the shear strength of angle connectors. Two regression metrics as determination coefficient (R2) and root mean square (RMSE) were used to measure the results of model. Furthermore, only four parameters in the predictive models are sufficient to provide an extremely precise prediction. It was found that GWO is a faster method and is able to achieve marginally higher output indices than in experiments.
{"title":"Application of multi-hybrid metaheuristic algorithm on prediction of split-tensile strength of shear connectors","authors":"Chao Liu, Y. Zandi, Abouzar Rahimi, Yongli Peng, G. Ge, M. Khadimallah, A. Issakhov, Subbotina Tatyana Yu","doi":"10.12989/SSS.2021.28.2.167","DOIUrl":"https://doi.org/10.12989/SSS.2021.28.2.167","url":null,"abstract":"Shear connectors play a major role in the development of composite steel concrete systems. The behavior of shear connectors is usually calculated by push-out measurements. These experiments are expensive and take a lot of time. Soft Computation (SC) may be applied as an additional solution to remove the need for push-out testing. The objective of the research is to explore the implementation, as sub-branches of the SC approaches, of artificial intelligence (AI) techniques for the prediction of advanced C-shaped shear connectors. To this end, multiple push-out tests on these connectors will be carried out and the requisite data is obtained for the AI models. The Grey Wolf Optimizer algorithm (GWO) is built to define the parameters that influence the shear strength of angle connectors. Two regression metrics as determination coefficient (R2) and root mean square (RMSE) were used to measure the results of model. Furthermore, only four parameters in the predictive models are sufficient to provide an extremely precise prediction. It was found that GWO is a faster method and is able to achieve marginally higher output indices than in experiments.","PeriodicalId":51155,"journal":{"name":"Smart Structures and Systems","volume":"28 1","pages":"167"},"PeriodicalIF":3.5,"publicationDate":"2021-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45651171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-01DOI: 10.12989/SSS.2021.28.2.229
Liangde Xu, Wen Jianian, Q. Han, Du Xiuli
Multiple variable frequency pendulum isolator (MVFPI) has been recently developed as a superior alternative to the traditional friction pendulum bearing (FPB) especially for the seismic isolation in near-fault regions. The MVFPI is characterized by its variable frequency and self-adaptability, which are achieved by piecewise function of sliding surface and shape memory alloy (SMA). The objective of this study is to propose the design algorithm of the MVFPIs in highway bridge as an extension of the direct displacement-based design (DDBD) framework. The nonlinearities of the structural components are taken into account in the design procedure, and the corresponding damage states satisfy the two-stage design philosophy. The accuracy and robustness of the design procedure are verified by an isolated four-span highway bridge through nonlinear time history (NLTH) analyses. The analytical results indicate that the proposed design procedure can predict the profile of deck displacement and amplitude, as well as the damage states of the piers. From statistic aspect, the fragility analyses illustrate that the bridge isolated by MVFPIs exhibits better seismic performance than that of the bridge isolated by FPBs.
{"title":"Seismic resistant design of highway bridge with multiple-variable frequency pendulum isolator","authors":"Liangde Xu, Wen Jianian, Q. Han, Du Xiuli","doi":"10.12989/SSS.2021.28.2.229","DOIUrl":"https://doi.org/10.12989/SSS.2021.28.2.229","url":null,"abstract":"Multiple variable frequency pendulum isolator (MVFPI) has been recently developed as a superior alternative to the traditional friction pendulum bearing (FPB) especially for the seismic isolation in near-fault regions. The MVFPI is characterized by its variable frequency and self-adaptability, which are achieved by piecewise function of sliding surface and shape memory alloy (SMA). The objective of this study is to propose the design algorithm of the MVFPIs in highway bridge as an extension of the direct displacement-based design (DDBD) framework. The nonlinearities of the structural components are taken into account in the design procedure, and the corresponding damage states satisfy the two-stage design philosophy. The accuracy and robustness of the design procedure are verified by an isolated four-span highway bridge through nonlinear time history (NLTH) analyses. The analytical results indicate that the proposed design procedure can predict the profile of deck displacement and amplitude, as well as the damage states of the piers. From statistic aspect, the fragility analyses illustrate that the bridge isolated by MVFPIs exhibits better seismic performance than that of the bridge isolated by FPBs.","PeriodicalId":51155,"journal":{"name":"Smart Structures and Systems","volume":"28 1","pages":"229"},"PeriodicalIF":3.5,"publicationDate":"2021-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48072310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-01DOI: 10.12989/SSS.2021.28.2.289
Bo Wang, H. Hou, Z. Zhut, Wang Xiao
An indispensable process of geotechnical modeling with transparent soils involves analyzing images and soil property simulations. This study proposes an objective framework for quantitative analysis of the influential mechanism of three key factors, namely, different aggregate proportions (DAP), solvent ratio (SR), and solute solution ratio (SSR) on transparent soils' transparency and shear strength. 125 groups of transparent soil samples considering these three factors were prepared to investigate their impact on transparency and shear strength through Elastic Net regression. Spearman correlation analysis was performed for transparency and shear strength. Furthermore, by comparing the performance of XGBoost, GBDT, Random Forest, and SVR after hyperparameter tuning in predicting transparency and shear strength, XGBoost proved to be the optimal machine learning model with the lowest MSE of 0.0048 and 0.0306 and was innovatively adopted to analyze how various factors affect the transparency and shear strength, thus enhancing the interpretability of machine learning. A ranking system, according to the importance scores of XGBoost, shows that SSR was the most important factor affecting both shear strength and transparency of transparent soils, with importance scores being 0.45 and 0.57, respectively. Our study may shed light on the preparation and performance study of transparent soils.
{"title":"Machine learning-based prediction and performance study of transparent soil properties","authors":"Bo Wang, H. Hou, Z. Zhut, Wang Xiao","doi":"10.12989/SSS.2021.28.2.289","DOIUrl":"https://doi.org/10.12989/SSS.2021.28.2.289","url":null,"abstract":"An indispensable process of geotechnical modeling with transparent soils involves analyzing images and soil property simulations. This study proposes an objective framework for quantitative analysis of the influential mechanism of three key factors, namely, different aggregate proportions (DAP), solvent ratio (SR), and solute solution ratio (SSR) on transparent soils' transparency and shear strength. 125 groups of transparent soil samples considering these three factors were prepared to investigate their impact on transparency and shear strength through Elastic Net regression. Spearman correlation analysis was performed for transparency and shear strength. Furthermore, by comparing the performance of XGBoost, GBDT, Random Forest, and SVR after hyperparameter tuning in predicting transparency and shear strength, XGBoost proved to be the optimal machine learning model with the lowest MSE of 0.0048 and 0.0306 and was innovatively adopted to analyze how various factors affect the transparency and shear strength, thus enhancing the interpretability of machine learning. A ranking system, according to the importance scores of XGBoost, shows that SSR was the most important factor affecting both shear strength and transparency of transparent soils, with importance scores being 0.45 and 0.57, respectively. Our study may shed light on the preparation and performance study of transparent soils.","PeriodicalId":51155,"journal":{"name":"Smart Structures and Systems","volume":"28 1","pages":"289"},"PeriodicalIF":3.5,"publicationDate":"2021-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47385342","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-01DOI: 10.12989/SSS.2021.28.2.275
Qilin Zhang, Siyuan Sun, B. Yang, R. Wüchner, Licheng Pan, Haitao Zhu
In this paper, a novel real-time structural health monitoring (SHM) system based on streaming data is proposed. In contrast to a traditional SHM system, the proposed system implements a series of optimizations for data transmission and processing to reduce the latency and better satisfy the real-time requirement. The concept of the watermark in the streaming system is adopted to address the problem of when to trigger the time window calculation under the real-time requirement. Moreover, a well-designed parallel mechanism is used to satisfy the multistage computation requirement in the parallel data stream. A case study in which the proposed system is applied to the Shanghai Tower is presented. The peak picking method is used as an example in the test environment to track the latency of each main operation under different parallelism schemes. The results show that computing in parallel effectively reduces the latency and provides a reference for integrating the random decrement technique (RDT), stochastic subspace identification (SSI), or other more complex but effective algorithms in parallel into the system in the future. The total latency under the test environment from data generation to data transmission to the web server is approximately only 200-400 ms, which indicates the excellent real-time performance of the system.
{"title":"Real-time structural health monitoring system based on streaming data","authors":"Qilin Zhang, Siyuan Sun, B. Yang, R. Wüchner, Licheng Pan, Haitao Zhu","doi":"10.12989/SSS.2021.28.2.275","DOIUrl":"https://doi.org/10.12989/SSS.2021.28.2.275","url":null,"abstract":"In this paper, a novel real-time structural health monitoring (SHM) system based on streaming data is proposed. In contrast to a traditional SHM system, the proposed system implements a series of optimizations for data transmission and processing to reduce the latency and better satisfy the real-time requirement. The concept of the watermark in the streaming system is adopted to address the problem of when to trigger the time window calculation under the real-time requirement. Moreover, a well-designed parallel mechanism is used to satisfy the multistage computation requirement in the parallel data stream. A case study in which the proposed system is applied to the Shanghai Tower is presented. The peak picking method is used as an example in the test environment to track the latency of each main operation under different parallelism schemes. The results show that computing in parallel effectively reduces the latency and provides a reference for integrating the random decrement technique (RDT), stochastic subspace identification (SSI), or other more complex but effective algorithms in parallel into the system in the future. The total latency under the test environment from data generation to data transmission to the web server is approximately only 200-400 ms, which indicates the excellent real-time performance of the system.","PeriodicalId":51155,"journal":{"name":"Smart Structures and Systems","volume":"28 1","pages":"275"},"PeriodicalIF":3.5,"publicationDate":"2021-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41627136","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-07-01DOI: 10.12989/SSS.2021.28.1.105
Hongwei Li, A. Maghareh, Johnny Condori Uribe, H. Montoya, S. Dyke, Zhao-dong Xu
Experiments involving soil-structure interaction are often constrained by the capacity and other limitations of the shake table. Additionally, it is usually necessary to consider different types of soil in experiments. Real-time hybrid simulation (RTHS) offers an alternative method to conduct such tests. RTHS is a cyber-physical testing technique that splits the dynamic system under investigation into numerical and physical components, and then realistically couples those components in a single test. A limited number of previous studies involving soil-structure interaction have been conducted using RTHS, with a focus on linear models and systems. The presence of isolators was not considered in these studies to the authors
{"title":"Advancing real-time hybrid simulation for coupled nonlinear soil-isolator-structure system","authors":"Hongwei Li, A. Maghareh, Johnny Condori Uribe, H. Montoya, S. Dyke, Zhao-dong Xu","doi":"10.12989/SSS.2021.28.1.105","DOIUrl":"https://doi.org/10.12989/SSS.2021.28.1.105","url":null,"abstract":"Experiments involving soil-structure interaction are often constrained by the capacity and other limitations of the shake table. Additionally, it is usually necessary to consider different types of soil in experiments. Real-time hybrid simulation (RTHS) offers an alternative method to conduct such tests. RTHS is a cyber-physical testing technique that splits the dynamic system under investigation into numerical and physical components, and then realistically couples those components in a single test. A limited number of previous studies involving soil-structure interaction have been conducted using RTHS, with a focus on linear models and systems. The presence of isolators was not considered in these studies to the authors","PeriodicalId":51155,"journal":{"name":"Smart Structures and Systems","volume":"28 1","pages":"105-119"},"PeriodicalIF":3.5,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43580955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-07-01DOI: 10.12989/SSS.2021.28.1.029
Bing Chen, Shi-Qi Li, Xiaolei Tang, Lijie Zhang
To improve the energy conversion efficiency and working frequency bandwidth of a single frequency piezoelectric vibration energy harvester, a new type of hybrid vibration energy harvester is developed which is combined with the mechanism of piezoelectric and electromagnetic energy conversion. The system comprises of a PZT cantilever beam, an elastic suspended magnetic mass, a magnet block attached to the end of the cantilever beam and a resonator. The addition of resonator can not only increase the mode, but also adjust the frequency of harvester flexibly. Nonlinear magnetic force of magnet block not only broadens the frequency band and improves the output performance of the system, but also changes the resonant frequency to make the harvester have better adjustable performance. On this basis, an improved electromechanical coupled analytical model of continuum is proposed which can be solved by the Runge-Kutta algorithm and the influence of different factors (the mass and spring stiffness of the resonator, as well as the electromechanical coupling coefficient, electromagnetic coupling coefficient, magnet mass and magnetic flux) on the output are analyzed. According to the prototype of the vibration energy harvester developed, an experimental system was built. The performance of the independent and hybrid energy harvesters is evaluated by experimental and analytical methods. The peak output voltage of the piezoelectric part was about 4 times that of the electromagnetic part. The peak output current of the electromagnetic part is about 30 times that of the piezoelectric part. The study results show that the proposed new hybrid vibration energy harvester can achieve a wider frequency range and multimodal vibration energy harvesting. In addition, the bandwidth and power of the harvester can be dynamically adjusted by changing the resonator or electromechanical coupling coefficient, and the bandwidth of the harvester can also be adjusted by changing the quality and characteristics of the magnet.
{"title":"A study of a new hybrid vibration energy harvester based on broadband-multimode","authors":"Bing Chen, Shi-Qi Li, Xiaolei Tang, Lijie Zhang","doi":"10.12989/SSS.2021.28.1.029","DOIUrl":"https://doi.org/10.12989/SSS.2021.28.1.029","url":null,"abstract":"To improve the energy conversion efficiency and working frequency bandwidth of a single frequency piezoelectric vibration energy harvester, a new type of hybrid vibration energy harvester is developed which is combined with the mechanism of piezoelectric and electromagnetic energy conversion. The system comprises of a PZT cantilever beam, an elastic suspended magnetic mass, a magnet block attached to the end of the cantilever beam and a resonator. The addition of resonator can not only increase the mode, but also adjust the frequency of harvester flexibly. Nonlinear magnetic force of magnet block not only broadens the frequency band and improves the output performance of the system, but also changes the resonant frequency to make the harvester have better adjustable performance. On this basis, an improved electromechanical coupled analytical model of continuum is proposed which can be solved by the Runge-Kutta algorithm and the influence of different factors (the mass and spring stiffness of the resonator, as well as the electromechanical coupling coefficient, electromagnetic coupling coefficient, magnet mass and magnetic flux) on the output are analyzed. According to the prototype of the vibration energy harvester developed, an experimental system was built. The performance of the independent and hybrid energy harvesters is evaluated by experimental and analytical methods. The peak output voltage of the piezoelectric part was about 4 times that of the electromagnetic part. The peak output current of the electromagnetic part is about 30 times that of the piezoelectric part. The study results show that the proposed new hybrid vibration energy harvester can achieve a wider frequency range and multimodal vibration energy harvesting. In addition, the bandwidth and power of the harvester can be dynamically adjusted by changing the resonator or electromechanical coupling coefficient, and the bandwidth of the harvester can also be adjusted by changing the quality and characteristics of the magnet.","PeriodicalId":51155,"journal":{"name":"Smart Structures and Systems","volume":"28 1","pages":"29"},"PeriodicalIF":3.5,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43204939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The falling offs of building decorative layers (BDLs) on exterior walls are quite common, especially in Asia, which presents great concerns to human safety and properties. Presently, there is no effective technique to detect the debonding of the exterior finish because debonding are hidden defect. In this study, the debonding defect identification method of building decoration layers via UAV-thermography and deep learning is proposed. Firstly, the temperature field characteristics of debonding defects are tested and analyzed, showing that it is feasible to identify the debonding of BDLs based on UAV. Then, a debonding defect recognition and quantification method combining CenterNet (Point Network) and fuzzy clustering is proposed. Further, the actual area of debonding defect is quantified through the optical imaging principle using the real-time measured distance. Finally, a case study of the old teaching-building inspection is carried out to demonstrate the effectiveness of the proposed method, showing that the proposed model performs well with an accuracy above 90%, which is valuable to the society.
{"title":"Debonding defect quantification method of building decoration layers via UAV-thermography and deep learning","authors":"Peng Xiong, Xingu Zhong, Anhua Chen, Chao Zhao, Canlong Liu, Y. Chen","doi":"10.12989/SSS.2021.28.1.055","DOIUrl":"https://doi.org/10.12989/SSS.2021.28.1.055","url":null,"abstract":"The falling offs of building decorative layers (BDLs) on exterior walls are quite common, especially in Asia, which presents great concerns to human safety and properties. Presently, there is no effective technique to detect the debonding of the exterior finish because debonding are hidden defect. In this study, the debonding defect identification method of building decoration layers via UAV-thermography and deep learning is proposed. Firstly, the temperature field characteristics of debonding defects are tested and analyzed, showing that it is feasible to identify the debonding of BDLs based on UAV. Then, a debonding defect recognition and quantification method combining CenterNet (Point Network) and fuzzy clustering is proposed. Further, the actual area of debonding defect is quantified through the optical imaging principle using the real-time measured distance. Finally, a case study of the old teaching-building inspection is carried out to demonstrate the effectiveness of the proposed method, showing that the proposed model performs well with an accuracy above 90%, which is valuable to the society.","PeriodicalId":51155,"journal":{"name":"Smart Structures and Systems","volume":"28 1","pages":"55-67"},"PeriodicalIF":3.5,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47653097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：