1
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Kim B, Oh J, Min C. Development of a Simulation Model for Digital Twin of an Oscillating Water Column Wave Power Generator Structure with Ocean Environmental Effect. SENSORS (BASEL, SWITZERLAND) 2023; 23:9472. [PMID: 38067845 PMCID: PMC10708887 DOI: 10.3390/s23239472] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 11/11/2023] [Accepted: 11/22/2023] [Indexed: 04/04/2024]
Abstract
This research article focuses on developing a baseline digital twin model for a wave power generator structure located in Yongsu-ri, Jeju-do, South Korea. First, this study performs a cause analysis on the discrepancy of the dynamic properties from the real structure and an existing simulation model and finds the necessity of modeling the non-structural masses and the environmental factors. The large amounts of the ballast are modeled in the finite element model to enhance the accuracy of the digital twin. Considering the influence of environmental factors such as tide level and wave direction, the added mass effect of structural members, one of the hydrodynamic effects, depending on the change of the ocean environments is calculated based on the rule of Det Norske Veritas and applied. The results indicate that non-structural mass components significantly impact the dynamic characteristics of the structure. Additionally, environmental factors have a greater effect on the dynamic behavior of the box-type structure compared to lightweight offshore structures.
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Affiliation(s)
- Byungmo Kim
- Ship and Offshore Technology Team, Korean Register, 36 Myeongji Ocean City 9-ro, Gangseo-gu, Busan 46762, Republic of Korea;
| | - Jaewon Oh
- Offshore Industries R&BD Center, Korea Research Institute of Ships & Ocean Engineering, 1350 Geojebuk-ro, Jangmok-Myeon, Geoje-si 53201, Gyeongsangnam-do, Republic of Korea;
| | - Cheonhong Min
- Offshore Industries R&BD Center, Korea Research Institute of Ships & Ocean Engineering, 1350 Geojebuk-ro, Jangmok-Myeon, Geoje-si 53201, Gyeongsangnam-do, Republic of Korea;
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2
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Li J, Yang J, Cai H, Jiang C, Jiang Q, Xie Y, Lu Z, Li L, Sun G. The Empty-Nest Power User Management Based on Data Mining Technology. SENSORS (BASEL, SWITZERLAND) 2023; 23:2485. [PMID: 36904691 PMCID: PMC10007684 DOI: 10.3390/s23052485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 02/17/2023] [Accepted: 02/20/2023] [Indexed: 06/18/2023]
Abstract
With the aging of the social population structure, the number of empty-nesters is also increasing. Therefore, it is necessary to manage empty-nesters with data mining technology. This paper proposed an empty-nest power user identification and power consumption management method based on data mining. Firstly, an empty-nest user identification algorithm based on weighted random forest was proposed. Compared with similar algorithms, the results indicate that the performance of the algorithm is the best, and the identification accuracy of empty-nest users is 74.2%. Then a method for analyzing the electricity consumption behavior of empty-nest users based on fusion clustering index adaptive cosine K-means was proposed, which can adaptively select the optimal number of clusters. Compared with similar algorithms, the algorithm has the shortest running time, the smallest Sum of the Squared Error (SSE), and the largest mean distance between clusters (MDC), which are 3.4281 s, 31.6591 and 13.9513, respectively. Finally, an anomaly detection model with an Auto-regressive Integrated Moving Average (ARIMA) algorithm and an isolated forest algorithm was established. The case analysis shows that the recognition accuracy of abnormal electricity consumption for empty-nest users was 86%. The results indicate that the model can effectively detect the abnormal behavior of empty-nest power users and help the power department to better serve empty-nest users.
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Affiliation(s)
- Jing Li
- College of Mechanical and Electrical Engineering, China Jiliang University, Hangzhou 310018, China
| | - Jiahui Yang
- College of Mechanical and Electrical Engineering, China Jiliang University, Hangzhou 310018, China
| | - Hui Cai
- College of Mechanical and Electrical Engineering, China Jiliang University, Hangzhou 310018, China
| | - Chi Jiang
- Electric Power Research Institute, State Grid Zhejiang Electric Power Co., Ltd., Hangzhou 310007, China
| | - Qun Jiang
- Electric Power Research Institute, State Grid Zhejiang Electric Power Co., Ltd., Hangzhou 310007, China
| | - Yue Xie
- College of Mechanical and Electrical Engineering, China Jiliang University, Hangzhou 310018, China
| | - Zimeng Lu
- College of Mechanical and Electrical Engineering, China Jiliang University, Hangzhou 310018, China
| | - Lingzhi Li
- College of Mechanical and Electrical Engineering, China Jiliang University, Hangzhou 310018, China
| | - Guanqun Sun
- College of Modern Science and Technology, China Jiliang University, Yiwu 322002, China
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3
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Bednarski Ł, Sieńko R, Howiacki T, Zuziak K. The Smart Nervous System for Cracked Concrete Structures: Theory, Design, Research, and Field Proof of Monolithic DFOS-Based Sensors. SENSORS (BASEL, SWITZERLAND) 2022; 22:8713. [PMID: 36433309 PMCID: PMC9696508 DOI: 10.3390/s22228713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 11/07/2022] [Accepted: 11/09/2022] [Indexed: 06/16/2023]
Abstract
The article presents research on the performance of composite and monolithic sensors for distributed fibre optic sensing (DFOS). The introduction summarises the design of the sensors and the theoretical justification for such an approach. Lessons learned during monitoring cracked concrete are summarised to highlight what features of the DFOS tools are the most favourable from the crack analysis point of view. Later, the results from full-size laboratory concrete specimens working in a cracked state were presented and discussed in reference to conventional layered sensing cables. The research aimed to compare monolithic sensors and layered cables embedded in the same reinforced concrete elements, which is the main novelty. The performance of each DFOS nondestructive tool was investigated in the close vicinity of the cracks-both the new ones, opening within the tension zone, and the existing ones, closing within the compression zone. The qualitative (detection) and quantitative (widths estimation) crack analyses were performed and discussed. Finally, the examples of actual applications within concrete structures, including bridges, are presented with some examples of in situ results.
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Affiliation(s)
- Łukasz Bednarski
- Faculty of Mechanical Engineering and Robotics, AGH University of Science and Technology in Krakow, Mickiewicza 30, 30-059 Krakow, Poland
| | - Rafał Sieńko
- Faculty of Civil Engineering, Cracow University of Technology, Warszawska 24, 31-155 Krakow, Poland
| | - Tomasz Howiacki
- Faculty of Civil Engineering, Cracow University of Technology, Warszawska 24, 31-155 Krakow, Poland
- SHM System Sp. z o.o., Sp. kom., Libertów, ul. Jana Pawła II 82A, 30-444 Kraków, Poland
| | - Katarzyna Zuziak
- Nerve-Sensors, Libertów, ul. Jana Pawła II 82A, 30-444 Kraków, Poland
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4
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Investigation on Applicability and Limitation of Cosine Similarity-Based Structural Condition Monitoring for Gageocho Offshore Structure. SENSORS 2022; 22:s22020663. [PMID: 35062624 PMCID: PMC8778841 DOI: 10.3390/s22020663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 01/06/2022] [Accepted: 01/07/2022] [Indexed: 12/03/2022]
Abstract
The key to coping with global warming is reconstructing energy governance from carbon-based to sustainable resources. Offshore energy sources, such as offshore wind turbines, are promising alternatives. However, the abnormal climate is a potential threat to the safety of offshore structures because construction guidelines cannot embrace climate outliers. A cosine similarity-based maintenance strategy may be a possible solution for managing and mitigating these risks. However, a study reporting its application to an actual field structure has not yet been reported. Thus, as an initial study, this study investigated whether the technique is applicable or whether it has limitations in the real field using an actual example, the Gageocho Ocean Research Station. Consequently, it was found that damage can only be detected correctly if the damage states are very similar to the comparison target database. Therefore, the high accuracy of natural frequencies, including environmental effects, should be ensured. Specifically, damage scenarios must be carefully designed, and an alternative is to devise more efficient techniques that can compensate for the present procedure.
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5
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Sakiyama FIH, Lehmann F, Garrecht H. A Novel Runtime Algorithm for the Real-Time Analysis and Detection of Unexpected Changes in a Real-Size SHM Network with Quasi-Distributed FBG Sensors. SENSORS 2021; 21:s21082871. [PMID: 33921865 PMCID: PMC8072662 DOI: 10.3390/s21082871] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 02/18/2021] [Accepted: 02/25/2021] [Indexed: 11/16/2022]
Abstract
The ability to track the structural condition of existing structures is one of the main concerns of bridge owners and operators. In the context of bridge maintenance programs, visual inspection predominates nowadays as the primary source of information. Yet, visual inspections alone are insufficient to satisfy the current needs for safety assessment. From this perspective, extensive research on structural health monitoring has been developed in recent decades. However, the transfer rate from laboratory experiments to real-case applications is still unsatisfactory. This paper addresses the main limitations that slow the deployment and the acceptance of real-size structural health monitoring systems (SHM) and presents a novel real-time analysis algorithm based on random variable correlation for condition monitoring. The proposed algorithm was designed to respond automatically to detect unexpected events, such as local structural failure, within a multitude of random dynamic loads. The results are part of a project on SHM, where a high sensor-count monitoring system based on long-gauge fiber Bragg grating sensors (LGFBG) was installed on a prestressed concrete bridge in Neckarsulm, Germany. The authors also present the data management system developed to handle a large amount of data, and demonstrate the results from one of the implemented post-processing methods, the principal component analysis (PCA). The results showed that the deployed SHM system successfully translates the massive raw data into meaningful information. The proposed real-time analysis algorithm delivers a reliable notification system that allows bridge managers to track unexpected events as a basis for decision-making.
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Affiliation(s)
- Felipe Isamu H. Sakiyama
- Institute of Science, Engineering and Technology (ICET), Federal University of the Jequitinhonha and Mucuri Valleys (UFVJM), Teófilo Otoni 39803-371, Brazil
- Materials Testing Institute (MPA), University of Stuttgart, 70569 Stuttgart, Germany; (F.L.); (H.G.)
- Correspondence:
| | - Frank Lehmann
- Materials Testing Institute (MPA), University of Stuttgart, 70569 Stuttgart, Germany; (F.L.); (H.G.)
| | - Harald Garrecht
- Materials Testing Institute (MPA), University of Stuttgart, 70569 Stuttgart, Germany; (F.L.); (H.G.)
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6
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Upper Limb Rehabilitation Tools in Virtual Reality Based on Haptic and 3D Spatial Recognition Analysis: A Pilot Study. SENSORS 2021; 21:s21082790. [PMID: 33921036 PMCID: PMC8071461 DOI: 10.3390/s21082790] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 04/06/2021] [Accepted: 04/13/2021] [Indexed: 11/17/2022]
Abstract
With aging, cerebrovascular diseases can occur more often. Stroke cases involve hemiplegia, which causes difficulties in performing activities of daily living. Existing rehabilitation treatments are based on the subjective evaluation of the therapist as the need for non-contact care arises; it is necessary to develop a system that can self-rehabilitate and offer objective analysis. Therefore, we developed rehabilitation tools that enable self-rehabilitation exercises in a virtual space based on haptics. Thirty adults without neurological damage were trained five times in a virtual environment, and the time, number of collisions, and coordinates were digitized and stored in real time. An analysis of variance (ANOVA) of the time and distance similarity changes revealed that as the number of rounds increased, no changes or increases occurred (p ≥ 0.05), and the collisions and paths were stable as the training progressed (p < 0.05). ANOVA showed a high correlation (0.90) with a decrease in the number of crashes and time required. It was meaningful to users when performing rehabilitation training more than four times and significantly impacted the analysis. This study analyzed the upper limb and cognitive rehabilitation of able-boded people in three-dimensional space in a virtual environment; the performance difficulty could be controlled through variations in rehabilitation models.
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7
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Entezami A, Sarmadi H, Behkamal B, Mariani S. Health Monitoring of Large-Scale Civil Structures: An Approach Based on Data Partitioning and Classical Multidimensional Scaling. SENSORS 2021; 21:s21051646. [PMID: 33652995 PMCID: PMC7956361 DOI: 10.3390/s21051646] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 02/12/2021] [Accepted: 02/19/2021] [Indexed: 11/16/2022]
Abstract
A major challenge in structural health monitoring (SHM) is the efficient handling of big data, namely of high-dimensional datasets, when damage detection under environmental variability is being assessed. To address this issue, a novel data-driven approach to early damage detection is proposed here. The approach is based on an efficient partitioning of the dataset, gathering the sensor recordings, and on classical multidimensional scaling (CMDS). The partitioning procedure aims at moving towards a low-dimensional feature space; the CMDS algorithm is instead exploited to set the coordinates in the mentioned low-dimensional space, and define damage indices through norms of the said coordinates. The proposed approach is shown to efficiently and robustly address the challenges linked to high-dimensional datasets and environmental variability. Results related to two large-scale test cases are reported: the ASCE structure, and the Z24 bridge. A high sensitivity to damage and a limited (if any) number of false alarms and false detections are reported, testifying the efficacy of the proposed data-driven approach.
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Affiliation(s)
- Alireza Entezami
- Department of Civil and Environmental Engineering, Politecnico di Milano, Piazza L. da Vinci 32, 20133 Milano, Italy;
- Department of Civil Engineering, Faculty of Engineering, Ferdowsi University of Mashhad, Mashhad 9177948944, Iran;
- Correspondence:
| | - Hassan Sarmadi
- Department of Civil Engineering, Faculty of Engineering, Ferdowsi University of Mashhad, Mashhad 9177948944, Iran;
| | - Behshid Behkamal
- Department of Computer Engineering, Faculty of Engineering, Ferdowsi University of Mashhad, Mashhad 9177948944, Iran;
| | - Stefano Mariani
- Department of Civil and Environmental Engineering, Politecnico di Milano, Piazza L. da Vinci 32, 20133 Milano, Italy;
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8
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Sensors for Structural Health Monitoring and Condition Monitoring. SENSORS 2021; 21:s21051558. [PMID: 33668107 PMCID: PMC7956286 DOI: 10.3390/s21051558] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 02/20/2021] [Indexed: 11/16/2022]
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9
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Yang J, Hou P, Yang C, Yang N, Li K. Damage Identification Method of Box Girder Bridges Based on Distributed Long-Gauge Strain Influence Line under Moving Load. SENSORS 2021; 21:s21030915. [PMID: 33572920 PMCID: PMC7866288 DOI: 10.3390/s21030915] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 01/25/2021] [Accepted: 01/25/2021] [Indexed: 11/16/2022]
Abstract
A new method was proposed for the damage identification of box girder bridges under moving load, wherein the difference of strain influence line (DSIL) was taken as an index to represent the long-gauge strain difference before and after damage. The damage identification theory based on long-gauge strain influence lines was derived for box girder bridges with shear lag effect under consideration, and a regularized index DSIL was proposed for the quantitative identifications of damage location and extent. A series of experiments were carried out to study the influences of speed, vehicle type, and vehicle weight on the damage identification, and the experimental data were obtained by long-gauge fiber Bragg grating strain sensors. Moreover, numerical simulations were performed to confirm the method. The experimental and numerical results show that the method can locate the damage accurately, and quantitatively identify the damage extent under different working conditions. The experimental damage extent is generally slightly higher than the theoretical, with an average identification error smaller than 5%. Additionally, the relative error of damage extent is smaller than 3% under different working conditions. Thus, the effectiveness of this method was verified.
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Affiliation(s)
- Jing Yang
- Key Laboratory of Concrete and Prestressed Concrete Structures of the Ministry of Education, School of Civil Engineering, Southeast University, Nanjing 210096, China; (J.Y.); (P.H.); (K.L.)
| | - Peng Hou
- Key Laboratory of Concrete and Prestressed Concrete Structures of the Ministry of Education, School of Civil Engineering, Southeast University, Nanjing 210096, China; (J.Y.); (P.H.); (K.L.)
| | - Caiqian Yang
- Key Laboratory of Concrete and Prestressed Concrete Structures of the Ministry of Education, School of Civil Engineering, Southeast University, Nanjing 210096, China; (J.Y.); (P.H.); (K.L.)
- College of Civil Engineering & Mechanics, Xiangtan University, Xiangtan 411105, China
- Correspondence:
| | - Ning Yang
- Shandong Institute of Space Electronic Technology, Yantai 264670, China;
| | - Kefeng Li
- Key Laboratory of Concrete and Prestressed Concrete Structures of the Ministry of Education, School of Civil Engineering, Southeast University, Nanjing 210096, China; (J.Y.); (P.H.); (K.L.)
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10
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Damage Detection of Bridges under Environmental Temperature Changes Using a Hybrid Method. SENSORS 2020; 20:s20143999. [PMID: 32708422 PMCID: PMC7412125 DOI: 10.3390/s20143999] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Revised: 07/12/2020] [Accepted: 07/15/2020] [Indexed: 12/16/2022]
Abstract
Principal component analysis (PCA)-based method is popular for detecting the damage of bridges under varying environmental temperatures. However, this method deletes some information when the damage features are projected in the direction of nonprincipal components; thus, the effectiveness of PCA-based methods will decrease if the deleted information is related to bridge damage. To address this issue, a hybrid method is proposed to detect the damage of bridges under environmental temperature changes. On one side, the PCA-based method is applied to deal with the nonprincipal components; on the other side, the Gaussian mixture method (GMM) is used to classify all the principal components into different clusters, and then the novel detection method is implemented to detect bridge damage for each cluster. In this way, all the damage feature information is saved and used to detect bridge damage. The numerical example and example of an actual bridge show that the proposed hybrid method is effective in detecting bridge damage under environmental temperature changes. The GMM is effective for classifying the natural monitoring frequency data of actual bridges, and the relationship between the natural frequencies of actual bridges and the environmental temperature is not always linear.
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11
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Puruncajas B, Vidal Y, Tutivén C. Vibration-Response-Only Structural Health Monitoring for Offshore Wind Turbine Jacket Foundations via Convolutional Neural Networks. SENSORS 2020; 20:s20123429. [PMID: 32560533 PMCID: PMC7349094 DOI: 10.3390/s20123429] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 06/15/2020] [Accepted: 06/16/2020] [Indexed: 11/16/2022]
Abstract
This work deals with structural health monitoring for jacket-type foundations of offshore wind turbines. In particular, a vibration-response-only methodology is proposed based on accelerometer data and deep convolutional neural networks. The main contribution of this article is twofold: (i) a signal-to-image conversion of the accelerometer data into gray scale multichannel images with as many channels as the number of sensors in the condition monitoring system, and (ii) a data augmentation strategy to diminish the test set error of the deep convolutional neural network used to classify the images. The performance of the proposed method is analyzed using real measurements from a steel jacket-type offshore wind turbine laboratory experiment undergoing different damage scenarios. The results, with a classification accuracy over 99%, demonstrate that the stated methodology is promising to be utilized for damage detection and identification in jacket-type support structures.
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Affiliation(s)
- Bryan Puruncajas
- Control, Modeling, Identification and Applications (CoDAlab), Department of Mathematics, Escola d’Enginyeria de Barcelona Est (EEBE), Universitat Politècnica de Catalunya (UPC), Campus Diagonal-Besós (CDB), Eduard Maristany, 16, 08019 Barcelona, Spain;
- Mechatronics Engineering, Faculty of Mechanical Engineering and Production Science (FIMCP), Escuela Superior Politécnica del Litoral (ESPOL), Guayaquil 09-01-5863, Ecuador;
| | - Yolanda Vidal
- Control, Modeling, Identification and Applications (CoDAlab), Department of Mathematics, Escola d’Enginyeria de Barcelona Est (EEBE), Universitat Politècnica de Catalunya (UPC), Campus Diagonal-Besós (CDB), Eduard Maristany, 16, 08019 Barcelona, Spain;
- Correspondence: ; Tel.: +34-934-137-309
| | - Christian Tutivén
- Mechatronics Engineering, Faculty of Mechanical Engineering and Production Science (FIMCP), Escuela Superior Politécnica del Litoral (ESPOL), Guayaquil 09-01-5863, Ecuador;
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12
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Big Data Analytics and Structural Health Monitoring: A Statistical Pattern Recognition-Based Approach. SENSORS 2020; 20:s20082328. [PMID: 32325821 PMCID: PMC7219663 DOI: 10.3390/s20082328] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 04/17/2020] [Accepted: 04/17/2020] [Indexed: 02/04/2023]
Abstract
Recent advances in sensor technologies and data acquisition systems opened up the era of big data in the field of structural health monitoring (SHM). Data-driven methods based on statistical pattern recognition provide outstanding opportunities to implement a long-term SHM strategy, by exploiting measured vibration data. However, their main limitation, due to big data or high-dimensional features, is linked to the complex and time-consuming procedures for feature extraction and/or statistical decision-making. To cope with this issue, in this article we propose a strategy based on autoregressive moving average (ARMA) modeling for feature extraction, and on an innovative hybrid divergence-based method for feature classification. Data relevant to a cable-stayed bridge are accounted for to assess the effectiveness and efficiency of the proposed method. The results show that the offered hybrid divergence-based method, in conjunction with ARMA modeling, succeeds in detecting damage in cases strongly characterized by big data.
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13
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Lin JF, Wang J, Wang LX, Law SS. Structural Damage Diagnosis-Oriented Impulse Response Function Estimation under Seismic Excitations. SENSORS (BASEL, SWITZERLAND) 2019; 19:E5413. [PMID: 31835297 PMCID: PMC6960957 DOI: 10.3390/s19245413] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 12/01/2019] [Accepted: 12/02/2019] [Indexed: 11/17/2022]
Abstract
Impulse response function (IRF) is an ideal structural damage index for the identification of structural damage associated with changes in modal properties. However, IRFs from multiple excitations applied at different degrees-of-freedoms jointly contribute to the dynamic response, and their estimation is often underdetermined. Although some efforts have been devoted to the estimation of IRF for a structure under single excitation, the case under multiple excitations has not been fully investigated yet. The estimation of IRF under multiple excitations is generally an ill-conditioned inverse problem such that an incorrect or non-feasible solution is common, preventing its application to damage detection. This work explores this problem by introducing dimensionality reduction transformation matrices relating two sets of IRFs of a structure with discussions on the performance of the non-unique transformation matrices. Then, the extraction of IRF via wavelet-based and Tikhonov regularization-based methods are compared. Finally, a numerical study with a truss structure is conducted to validate the estimation of the IRFs and to demonstrate their applicability for damage detection under seismic excitations. Both the damage locations and severity are accurately identified, indicating the proposed methodology can enable the IRFs estimation under multiple excitations for successful damage detection.
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Affiliation(s)
- Jian-Fu Lin
- Center of Safety Monitoring of Engineering Structures, Shenzhen Academy of Disaster Prevention and Reduction, China Earthquake Administration, Shenzhen 518003, China; (J.-F.L.); (L.-X.W.)
| | - Junfang Wang
- College of Civil and Transportation Engineering, Shenzhen University, Shenzhen 518060, China
| | - Li-Xin Wang
- Center of Safety Monitoring of Engineering Structures, Shenzhen Academy of Disaster Prevention and Reduction, China Earthquake Administration, Shenzhen 518003, China; (J.-F.L.); (L.-X.W.)
| | - Siu-seong Law
- School of Civil Engineering, Chongqing University, Chongqing 400045, China;
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