Publications
161 results found
Ceri S, Khodaei ZS, 2024, Numerical investigation of hypervelocity impact simulation with FEM/SPH formulation for space structures, International Journal of Impact Engineering, Vol: 187, ISSN: 0734-743X
This paper investigates the response of aluminum structures to hypervelocity impact (HVI) and the formation of debris clouds using the Adaptive Finite Element (FEM)/Smoothed Particle Hydrodynamics (SPH) method. The main objective is to accurately replicate the response of curved thin plates to various HVIs and to characterize the resulting debris cloud shapes., for representative of shielding structures against Micrometeoroids and Orbital Debris (MMOD). In particular, the effects of different solid element formulations on the adaptive method are investigated. Experimental data from the literature is used to validate the proposed model, which is then applied to a curved thin plate subjected to varying impact angles. The findings highlight the significant influence of solid element formulation on the effectiveness of the adaptive method. Moreover, a direct correlation is observed between the impact angle and the produced debris cloud shape. These results contribute to the current knowledge on HVI responses and provide valuable insights for predicting and analyzing debris cloud formation in relation to aluminum structures.
Li Y, Sharif-Khodaei Z, 2024, A novel damage detection method for carbon fibre reinforced polymer structures based on distributed strain measurements with fibre optical sensor, Mechanical Systems and Signal Processing, Vol: 208, ISSN: 0888-3270
This paper presents a novel approach for damage detection in carbon fibre reinforced polymer (CFRP) structures based on local strain feature matching. The proposed approach utilizes distributed in-plane strain measurements for plate structures under load (in-service application) to define a local point autocorrelation coefficient based on Delaunay triangulation and Hausdorff distance. This coefficient effectively identifies the discontinuities in distributed in-plate strain, enabling accurate capture of damage information through the damage index which is defined as the integral of this coefficient. Notably, the proposed approach requires no prior knowledge of the non-damaged strain distribution and yields excellent detection results for both Barely Visible Impact Damage (BVID) and Visible Impact Damage (VID). Leveraging the advantages of distributed strain sensing, coupled with image processing technology for the purpose of in-service damage detection of CFRP structures, the proposed novel method is a promising technology. The efficacy of this technology has been demonstrated in this paper through theoretical analysis and experimental investigations, offering valuable insights and reference for future research in this domain.
Ren F, Giannakeas IN, Sharif Khodaei Z, et al., 2024, The temperature effects on embedded PZT signals in structural health monitoring for composite structures with different thicknesses, NDT and E International, Vol: 141, ISSN: 0963-8695
Ultrasonics guided waves (GWs) are established as an effective structural health monitoring technique for detecting damage in composite structures. However, for GWs to be applied reliably in service, the effect of temperature needs to be accounted for baseline damage detection approaches. Previous studies have focused on developing temperature compensation methods for surface-mounted transducers. In this paper, an extensive investigation has been carried out to develop an effective temperature compensation method for GWs generated by embedded transducers in different thickness composites. To accomplish this, Laser Doppler Vibrometer experiments were carried out to obtain wavenumbers generated by embedded transducers and to compare them against surface mounted cases. The consistent trend observation of dispersion curves between surface-mounted and embedded PZTs serves as a foundation for conducting analysis of the embedded signals with the effect of temperature. Following that, GW propagation has been studied in three quasi-isotropic composites of 2 mm, 4 mm and 9 mm thicknesses. Based on the established temperature database with measurements from − 50 °C to 70 °C, a temperature compensation methodology has been developed and validated with the temperature difference of 30 °C. It demonstrates that the temperature effect on the embedded PZTs is lower in comparison to surface mounted PZTs, and the temperature compensation of a single thickness composite is scalable to other panels thickness. This novel methodology proves beneficial in reducing the scale of the experimental campaign required, which holds significant value for actual aeronautical structures characterized by variable composite thicknesses across different sections, such as in fuselage panels or wing boxes.
Ren F, Giannakeas IN, Alibadi F, et al., 2024, The Sensitivity Analysis of Group Velocity to Temperature Variations in Composite Structures, Pages: 730-739
Temperature variations have a significant impact on the propagation characteristics of guided waves, which further affect the accuracy and reliability of damage detection, necessitating a comprehensive understanding of the response of group velocity to temperature. This study focuses on developing a model framework to analyze the sensitivity of the group velocity to temperature variations in composite structures. The relationship between the group velocity, frequency, and thickness is first established using the SAFE model. Furthermore, the effect of temperature on group velocity is investigated by obtaining temperature-dependent material properties through mechanical testing. By quantifying the sensitivity of group velocity to temperature variations, the extent of temperature influence on guided wave group velocity can be determined. It is demonstrated that the group velocity with temperature remains consistent within specific frequency and thickness ranges, specifically, f · d : 300 kHz · mm − 840 kHz · mm for A0 mode and 0 kHz · mm − 500 kHz · mm for S0 mode. These findings carry substantial implications for the application of temperature compensation methods regarding group velocity in composite panels of varying thicknesses to reduce the collection of temperature signals.
Morse L, Giannakeas IN, Mallardo V, et al., 2024, Multi-objective SHM sensor path optimisation for damage detection in large composite stiffened panels, Structural Health Monitoring, ISSN: 1475-9217
This work proposes a novel methodology for the automatic multi-objective optimisation of sensor paths in structural health monitoring (SHM) sensor networks using archived multi-objective simulated annealing. Using all of the sensor paths within a sensor network may not always be beneficial during damage detection. Many sensor paths may experience significant signal noise, attenuation, and wave mode conversion due to the presence of features, such as stiffeners, and hence impair the detection accuracy of the overall system. Many paths will also contribute little to the overall coverage level or damage detection accuracy of the network and can be ignored, reducing complexity. Knowing which paths to include, and which to exclude, can require significant prior expert knowledge, which may not always be available. Furthermore, even when expert knowledge is considered, the optimum path selection might not be achieved. Therefore, this work proposes a novel automatic procedure for optimising the sensor paths of an SHM sensor network to maximise coverage level, maximise damage detection accuracy and minimise the overall signal noise in the network due to geometric features. This procedure was tested on a real-world large composite stiffened panel with many geometric features in the form of frames and stiffeners. Compared to using all of the available sensor pairs, the optimised network exhibits superior performance in terms of detection accuracy and overall noise. It was also found to provide very similar performance, in terms of coverage level and overall signal noise, to a sensor path network designed based on prior expert knowledge but provided up to 35% higher damage detection accuracy. As a result, the novel procedure proposed in this work has the capability to design high-performing SHM sensor path networks for structures with complex geometries but without the need for prior expert knowledge, making SHM more accessible to the engineering community.
Marrazzo M, Aliabadi FMH, Sharif-Khodaei Z, 2023, Laplace domain boundary element method for structural health monitoring of poly-crystalline materials at micro-scale, Applied Sciences MDPI, Vol: 13, ISSN: 2076-3417
This paper describes for the first time the application of an Elastodynamic Boundary Element Method (BEM) in Laplace domain for Structural Health Monitoring (SHM) of poly-crystalline materials. The study focuses on Ultrasonic Guided Wave (UGW) propagation and investigates the wave-material interaction at micro-scale. The study aims to investigate the interaction of UGWs with micro-structural features such as grain size, morphology, degradation, and flaws. Numerical simulations of the most common micro-structural features demonstrate the accuracy and validity of the proposed method. Particular attention is paid to the study of porosity and its influence on material macro-properties. Different crystal morphologies such as cubic, rhombic, and truncated octahedral are considered. The detection of voids based on the changes in the amplitude and Time of Arrival (ToA) of the backscattered signal is investigated. The study also considers intergranular cracks which cause laceration and examines flaw position/orientation, length, and distance from a specific reference. Furthermore, a framework is proposed for generating Probability of Detection (PoD) curves using numerical simulations. Experimental tests in pristine conditions are shown to be in good agreement with the numerical simulations in terms of ToA, signal amplitude, and wave velocity. The numerical simulations provide insights into wave propagation and wave-material interaction, including different types of defects at the micro-scale. Overall, the BEM and UGW methods are shown to provide an effective tool for better understanding the micro-structural features and their influence on the macro-structural properties of poly-crystalline materials.
Zhuang M, Morse L, Khodaei ZS, et al., 2023, Implicit Differentiation-Based Reliability Analysis for Shallow Shell Structures with the Boundary Element Method (vol 156, pg 223, 2023), ENGINEERING ANALYSIS WITH BOUNDARY ELEMENTS, Vol: 157, Pages: 166-166, ISSN: 0955-7997
Li H, Khodaei ZS, Aliabadi MHF, 2023, FFT-based multiscale scheme for homogenisation of heterogeneous plates including damage and failure, Computer Methods in Applied Mechanics and Engineering, Vol: 416, ISSN: 0045-7825
This paper introduces a new approach that combines FFT-based multiscale homogenisation with the Lippman–Schwinger equation to efficiently and accurately analyse plate structures with periodic micro-structures. For the first time, the plate periodic Lippman–Schwinger equation is derived to address the auxiliary cell problem. The proposed method comprises two key components: (i) a 3D plate formulation using a novel finite prism approach, and (ii) solving the Lippman–Schwinger equations by means of Green's functions. Solutions for both the classical and first-order plate theories are derived and implemented for linear and nonlinear problems, completed with an open-source code provided. The efficiency and accuracy of the proposed method are assessed through several case studies, including complex woven composites. It is demonstrated that proposed method achieves a comparable level of accuracy to 3D solid problems while significantly reducing the required computing effort (i.e., milliseconds in computing time as opposed to hours required for 3D solid models). Moreover, nonlinear progressive damage problem involving an actual plate woven composite model is investigated. The results obtained show good agreement with experimental measurements for the progressive damage in plain woven composite, further highlighting the effectiveness of the proposed method.
Zhuang M, Morse L, Khodaei ZS, et al., 2023, Implicit differentiation-based reliability analysis for shallow shell structures with the Boundary Element Method, ENGINEERING ANALYSIS WITH BOUNDARY ELEMENTS, Vol: 156, Pages: 223-238, ISSN: 0955-7997
- Author Web Link
- Cite
- Citations: 1
Ren F, Giannakeas IN, Khodaei ZS, et al., 2023, Theoretical and experimental investigation of guided wave temperature compensation for composite structures with different thicknesses, MECHANICAL SYSTEMS AND SIGNAL PROCESSING, Vol: 200, ISSN: 0888-3270
Rodrigues FDS, Giannakeas IN, Khodaei ZS, et al., 2023, Probability based damage detection on a composite fuselage panel based on large data set of guided wave signals, NDT & E INTERNATIONAL, Vol: 139, ISSN: 0963-8695
Giannakeas IN, Mazaheri F, Bacarreza O, et al., 2023, Probabilistic residual strength assessment of smart composite aircraft panels using guided waves, RELIABILITY ENGINEERING & SYSTEM SAFETY, Vol: 237, ISSN: 0951-8320
- Author Web Link
- Cite
- Citations: 1
Ren F, Giannakeas IN, Khodaei ZS, et al., 2023, Sensitivity analysis of temperature effects on guided wave-based damage detection, MECHANICAL SYSTEMS AND SIGNAL PROCESSING, Vol: 196, ISSN: 0888-3270
- Author Web Link
- Cite
- Citations: 1
Reichmann B, Sharif-Khodaei Z, 2023, Ultrasonic guided waves as an indicator for the state-of-charge of Li-ion batteries, Journal of Power Sources, Vol: 576, Pages: 1-11, ISSN: 0378-7753
Conventional battery management systems rely on cell voltage, current, and temperature to predict the battery state-of-charge and state-of-health, but their accuracy is limited. To overcome this limitation, ultrasonic probing has been proposed as a novel battery monitoring technique. This paper introduces the use of ultrasonic chirp signals for the transfer of ultrasound-based battery monitoring techniques without requiring prior knowledge of the architecture of the cell. To validate this technique, small, lightweight piezoelectric disc transducers that can be easily installed on off-the-shelf battery pouch cells were utilized for large cells with a capacity of 12.5 Ah. Furthermore, the dominant frequency of the response signal to a Hanning-windowed tone burst signal was identified as a quantitative state-of-charge indicator. A predictive model was developed to compare the performance of this indicator with that of previous ultrasound-based state-of-charge prediction methods. The influence of the cell temperature and cycle age on ultrasonic guided wave propagation was also investigated and isolated for analysis.
Dagsever F, Khodaei ZS, Aliabadi MH, 2023, Development of a cyber-physical SHM system for composite structures, ISSN: 0094-243X
This paper is intended to present a comprehensive approach including the design of a cyber-physical system (CPS) for structural health monitoring (SHM) of composite aircraft structures. The paper summarises the developments of a miniaturised data acquisition (DAQ) unit. Afterwards, the existing Wireless Sensor Networks (WSNs) based SHM technologies are presented and compared to develop a new approach. This new approach is the CPS for SHM consisting of a miniaturised on-board DAQ, WSN and a user-friendly graphical user interface (GUI). The cyber and physical parts of the CPS are separately covered in detail. To manage the entire system, a concept is addressed to define all the stages and components of how to work together during the monitoring of structural integrity. This concept involves data acquisition, the transmission of sensing results wirelessly, data visualisation and processing using a developed software with GUI. The proposed CPS for SHM shows that it is a promising and time-efficient system for multi-stage and multi-disciplinary SHM applications. This approach does not require other software tools such as LabView and Matlab to visualise and process sensor data. All systems are integrated into one platform with this concept. Another advantage is that the proposed system is flexible to be improved by adding new features to the software developed in the cyber part of the CPS. Additionally, the CPS is convenient for on-board aircraft SHM applications with a wireless miniaturised DAQ unit powered by the software with GUI.
Haolin LI, Khodaei ZS, Aliabadi MHF, 2023, Multiscale modelling of the degradation and fracture of plain woven composites, ISSN: 0094-243X
A multi-scale modelling framework for investigating the non-linear mechanical behaviour of plain woven composites is proposed. The macro and micro simulations are coupled by a developed interface in which the mechanical behaviour of the micro-structure is served as the constitutive law of macro-continuum. The degradation and failure that occur at the macro structure are integrated with the micro-cracks in such a case. Some problems, e.g. the stress localisation effect introduced by the discontinuity of the multi-scale structures, are solved by the introduction of the non-local approach. Besides, the machine learning model is adopted for the surrogate modelling to realise the reduction of the substantial computational source required by the multi-scale problem. Cases are investigated in this paper in which a good agreement of the obtained simulation results to predictions is obtained.
Buchinger V, Khodaei ZS, Aliabadi MH, 2023, Development of 3D-printed flexible devices for strain sensing and damage detection, ISSN: 0094-243X
Advances in wearable electronics and soft electronics have led to the development of novel manufacturing techniques for electronic circuitry. This work utilizes the unique properties of flexible printed devices for strain sensing and damage detection. Inks made from Thermoplastic Polyurethane (TPU) and a mix of different solvents are used for insulation and adhesion to the monitored structure. Silver particles are added to the ink for conductivity. A robotic arm controlled by customized printing programs delivers high resolution prints directly onto the structures for testing. Finally, carbon-fiber-reinforced thermoplastic-matrix Open Hole Tension (OHT) coupons are subjected to tensile loading and the strain sensing and damage-detection capabilities are demonstrated.
Li Y, Khodaei ZS, 2023, 2D strain field reconstruction of composite plates based on distributed fibre optic sensors, ISSN: 0094-243X
In this work, the strain reconstruction with interpolation methods was investigated based on measurements of distributed fibre optical sensors. The strain measurements under different sensor densities (5,10,15,⋯, 30mm) were adopted in this investigation. The measurements under 5mm distance were adopted as true strain distribution (high-fidelity data). The other measurements were interpolated to 5mm by barycentric Lagrange and cubic spline methods. These interpolated results were adopted as the low-fidelity data and to compare with the true strain distribution. The results show that the accuracy of strain reconstruction decreases with the increase of sensors distance. Specifically, the local patterns of strain distribution are lost after the reconstruction when the sensor distance of measurement data is much larger (≥6 times) than the sensor distance of reconstruction data. However, the main trends of the reconstructed strain distribution are consistent with the true strain distribution. In addition, the barycentric Lagrange interpolation shows better stability than the cubic spline interpolation, especially for measurements with large sensor distance.
Giannakeas IN, Khodaei ZS, Aliabadi FMH, 2023, Application of the digital clone framework for SHM systems through the building block scales, ISSN: 0094-243X
A major challenge for the industrial adoption of guided wave based Structural Health Monitoring (SHM) systems in the aerospace industry is the reliable prediction of the system's response under a wide range of damage scenarios and operational conditions. Extensive experimental campaigns in large scale composite aeronautical structures however are not feasible. The digital clone framework, presented in [1], combines numerical simulations with experimental observations and is employed here to leverage information collected at the lower scales of the building block, where a larger number of samples can be tested, to make estimations on the system's response at higher scales. The aim is to develop a methodology that can estimate the SHM indications in the presence of damage considering the underlying uncertainties. Experimental observations at the coupon scale (0.3m) are used for initial training and the up-scaling capability of the methodology is validated against tests performed on a 1.6m flat stiffened panel. The estimations of the proposed approach agree with the experimental values while subsequent recalibration as more observations become available can further improve the predictions.
Deng Q, Khodaei ZS, 2023, Vibration-based damage detection of offshore wind turbine, ISSN: 0094-243X
This paper reports on the use of a novel approach to combine numerical and experimental results for Structural Health Monitoring to determine the existence of damage on a section of an anisotropic composite component, representative of a wind turbine blade section, based on its vibration response. Impacts are generated using a hammer and shaker respectively and the guided wave data was acquired via passive sensing by MEMS accelerometers. With Frequency Response Method, the natural modes are extracted from the computed Power Spectral Density plot. The 5% deviation of those natural modes compared to the pristine case was sufficient to identify the existence of the structural damage. The experimentally obtained natural modes were further validated by the Finite Element model in ABAQUS. A threshold of ±3Hz was assigned to lower modes to avoid false alarms due to environmental factors(e.g temperatures and humidity) under pristine conditions. By observing the deviation in the pristine natural modes, the probability of having false alarms is only 2.25%, while the probability of detecting an artificial damage (100g added mass) is 75.89% and 88.65% for shaker-induced and hammer-induced vibration tests respectively. As the severity of the damage increased (higher mass), there was an increase in the detection probability, to 89.36% and 96.45% for a 200g added mass damage scenario. It was observed experimentally and numerically that if the damage is located where a specific mode's displacement is expected to be highest under resonance, the corresponding frequency will show a significant shift which can be utilised to subsequently localise the damage. Therefore a frequency map of the structure is proposed to utilise spatial dependent natural modes to detect damage with high reliability.
Tam KP, Rodrigues FDS, Giannakeas I, et al., 2023, Augmented reality and decision making for structural health monitoring application, ISSN: 0094-243X
The applications of structural health monitoring generate substantial, heterogeneous data sets of which can only be interpreted by specific programs operated by trained personnel. Effective visualisations aim to provide maintenance engineers with real-time feedback on decision making by interpreting these data into human-comprehensible visuals. This has been achieved by using augmented reality, where information can be integrated with the user's viewing environment. Unity Engine was used on Windows to develop the Android ARSHM mobile application, with the aim to produce a framework for documenting and visualising data from the monitored structures. The documentation aspect allows the user to annotate on a photograph of the scene, while visualisations include sensors and damage visualisations that localise and overlay the physical environment with visuals. The app has been optimised by pre-processing computations and storing data external to the mobile device, hence reducing the mobile computational effort. QR codes and Google Drive were used as the two channels of external storage and have been integrated with the app. The app has been tested with various sensorised structures under pristine and damaged states. Two external MATLAB Apps have been developed to facilitate the use of the ARSHM app, namely the QR Generator for generating QR codes that store physical data and the RGB Generator for generating the damage index matrices that store diagnosis results.
Marrazzo M, Khodaei ZS, Aliabadi MHF, 2023, Microstructural identification of poly-crystalline materials using the Laplace domain DBEM formulation for SHM purposes, ISSN: 0094-243X
This paper investigates the modelling of Ultrasonic Guided wave propagation in poly-crystalline materials (metallic, ceramic...) with the Boundary Element Method. The Dual Boundary Element Method (DBEM) formulation in elastodynamics is used. In particular, the formulation in Laplace domain is implemented. The DBEM is developed to investigate how the micro-structural features affect the macro-structural properties of poly-crystalline materials. The aim is to develop both numerical and mathematical models of ultrasonic wave propagation to investigate the relationship between the micro-structural properties (grain size, distribution, degradation, micro flaws, cracking) and changes to the guided waves. The DBEM in Laplace domain is developed for Non-Destructive-Testing (NDT) of poly-crystalline structure. Structural Health Monitoring (SHM) is among NDT technique which has increased its employment in material evaluation and testing. The application of the BEM with Ultrasonic Guided Waves as numerical tool for SHM purposes of polycrystalline material is the main novelty of this work. Numerical simulations and results are shown in this work, highlighting which are the most common micro-structural features present in polycrystals and how to detect them.
Asadi S, Khodaei ZS, Aliabadi MH, et al., 2023, A baseline free methodology for crack detection in metallic bolted joints, ISSN: 0094-243X
Cracks initiated from bolt holes are the main failure that occurs in metallic bolted joints. This paper proposes a methodology based on PZT-generated guided waves to detect through thickness cracks on bolt holes without needing a baseline to compare the current state of the structure to. First a near optimal configuration of PZT arrays is sought with a finite element model in which the reflected wave from cracked hole has the maximum amplitude. Based on the calculated array of transducers two Aluminum structures comprised of skin and stiffener jointed with bolts are equipped with transducers. In the first structure, a 1 mm crack is detected with a proposed damage index (DI) on a 10 mm hole based on standard deviation and comparing signals from different paths and actuator-sensor combination. Second structure is used to show correlation of crack length with the proposed DI. It indicates a steep increase in the DI when the crack is larger than 1 mm.
Ren F, Giannakeas IN, Khodaei ZS, et al., 2023, The influence of temperature on barely visible impact damage detection, ISSN: 0094-243X
The wide range of operational and environmental conditions of flight, makes guided wave damage detection methods challenging without compensating the effects of temperature. Reliable temperature compensation algorithms have been proposed to correct the effect of temperature difference between baseline and current signals, which relies on the knowledge of the temperature at the pristine state of the structure for which the guides waves are recorded. This paper investigates the influence of variation in the temperature measurement and its effect on guided wave signals features and consequently barely visible impact damage (BVID) detection in composite plates under operational environmental conditions. With measurements collected using an environmental chamber at a 5°C step, the peak residual value between baseline and current signals is used to calculate damage index (DI), followed by a further investigation on the variation of damage detection results under temperature variations. The results have confirmed better results are obtained at a baseline temperature of 20°C compared to a baseline temperature of 45°C.
Zhu H, Khodaei ZS, Aliabadi MH, 2023, Investigation into autoregressive model signal compression for damage localisation, ISSN: 0094-243X
The guided wave-based structural health monitoring (GWSHM) has witnessed its rapid developments during the past decades. As an effective technique widely utilised for damage detection in the realm of the GWSHM, the autoregressive (AR)-based approach, however, has not been extensively investigated for damage localisation in the previous research. In this paper, an effective and efficient approach based on the signal compression and the autoregressive modelling of ultrasonic signals is proposed for the GWSHM with particular emphasis on the damage localisation of composite structures. The damage localisation results indicate that the proposed method outperforms the typical RAPID (Reconstruction Algorithm for Probabilistic Inspection of Damage) algorithm when predicting true damage locations and is robust against varying compression ratios.
Cheng X, Khodaei ZS, 2023, Temperature calibration for guided wave hybrid system with FBG-based Fabry-Perot sensor, JOURNAL OF INTELLIGENT MATERIAL SYSTEMS AND STRUCTURES, Vol: 34, Pages: 766-784, ISSN: 1045-389X
Li Y, Sharif-Khodaei Z, 2023, Accuracy of Distributed Strain Sensing with Single-Mode Fibre in Composite Laminates under Thermal and Vibration Loads, Structural Control and Health Monitoring, Vol: 2023, Pages: 1-13, ISSN: 1545-2255
<jats:p>In this work, the strain measurement accuracy of single-mode fibre (SMF) under thermal and vibration loads is investigated by strain-frequency shift coefficient analyses. This research allows for the application of SMF sensors for structural health monitoring in real operational conditions. The strain measurement accuracy under combined static and thermal load is investigated experimentally, which demonstrated that temperature fluctuations induce non-negligible errors in the strain measurement, even with temperature compensation applied. The temperature fluctuation range which can induce measurement errors is quantified as less than −20<jats:inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" id="M1"><mo>°</mo></math></jats:inline-formula>C or higher than 55<jats:inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" id="M2"><mo>°</mo></math></jats:inline-formula>C. In addition, a fatigue experiment is conducted to investigate the measurement accuracy under low-frequency vibration load. The results of the fatigue experiment demonstrate that the vibrations mainly increase the ratio of null values in strain measurements. Findings from experiments can be applied to enhance structural health monitoring accuracy and reduce false positives. This study has important implications for the service application of distributed optical fibre sensing for composite structure health monitoring.</jats:p>
Li Y, Sharif Khodaei Z, 2023, Accuracy of distributed strain sensing with single mode fibre in composite laminates under thermal and vibration loads, Structural Control and Health Monitoring, Vol: 2023, Pages: 1-13, ISSN: 1545-2255
In this work, the strain measurement accuracy of single-mode fibre (SMF) under thermal and vibration loads is investigated by strain-frequency shift coefficient analyses. This research allows for the application of SMF sensors for structural health monitoring in real operational conditions. The strain measurement accuracy under combined static and thermal load is investigated experimentally, which demonstrated that temperature fluctuations induce non-negligible errors in the strain measurement, even with temperature compensation applied. The temperature fluctuation range which can induce measurement errors is quantified as less than −20°C or higher than 55°C. In addition, a fatigue experiment is conducted to investigate the measurement accuracy under low-frequency vibration load. The results of the fatigue experiment demonstrate that the vibrations mainly increase the ratio of null values in strain measurements. Findings from experiments can be applied to enhance structural health monitoring accuracy and reduce false positives. This study has important implications for the service application of distributed optical fibre sensing for composite structure health monitoring.
Li H, Khodaei ZS, Aliabadi MHF, 2023, Multiscale modelling of material degradation and failure in plain woven composites: A novel approach for reliable predictions enabled by meta-models, COMPOSITES SCIENCE AND TECHNOLOGY, Vol: 233, ISSN: 0266-3538
- Author Web Link
- Cite
- Citations: 2
Giannakeas IN, Khodaei ZS, Aliabadi MH, 2023, An up-scaling temperature compensation framework for guided wave-based structural health monitoring in large composite structures, STRUCTURAL HEALTH MONITORING-AN INTERNATIONAL JOURNAL, Vol: 22, Pages: 777-798, ISSN: 1475-9217
- Author Web Link
- Cite
- Citations: 9
This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.