Article
Engineering, Mechanical
Szymon Gres, Michael Dohler, Laurent Mevel
Summary: The Modal Assurance Criterion (MAC) is a modal indicator used to determine if mode shapes correspond to the same mode in structural monitoring. The MAC inherits statistical properties when estimated from measurement data, leading to uncertainty in its evaluation. MAC estimates for different mode shapes have a Gaussian approximation, while estimates for equal mode shapes are linked to a v2 distribution.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2021)
Article
Construction & Building Technology
Atefeh Soleymani, Hashem Jahangir, Maria Rashidi, Farid Fazel Mojtahedi, Michael Bahrami, Ahad Javanmardi
Summary: This study focuses on using time-domain modal testing and wavelet analysis to identify damage in reinforced concrete (RC) beams. A numerical model was used to simulate different damage scenarios. Damage indices derived from wavelet analysis were employed to determine the severity and location of the damage. The study found that different wavelet families and specific mother wavelets had varying effectiveness in detecting damage.
Article
Engineering, Marine
Chun-Xu Qu, Chang-Chong Liu, Xiao-Mei Yang, Hui-Juan Liu, Hong-Nan Li, Yu-Feng Zhang
Summary: This paper proposes an innovative method to eliminate the effect of high ocean wind on modal identification by generating impulse response and using wind velocity spectrum and correlation function for elimination. The experimental results demonstrate the effectiveness of this method.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2022)
Article
Engineering, Mechanical
Szymon Gres, Michael Dohler, Palle Andersen, Laurent Mevel
Summary: In this study, a subspace identification method is developed to estimate structural parameters while rejecting the influence of periodic input. The periodic information is estimated with a non-steady state Kalman filter and removed from the original output signal by an orthogonal projection, resulting in consistent estimation of the modes of the structural system.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2021)
Article
Acoustics
Mingqiang Xu, Francis T. K. Au, Shuqing Wang, Huiyuan Tian
Summary: This paper proves that the presence of harmonic excitation only affects the identification of structural modes when the harmonic excitation frequencies are close to the structural frequencies. The paper proposes a Ramanujan subspace projection (RSP) method for removing the harmonic component from the mixed random and harmonic system output. The method directly extracts the harmonic component from a specific complex conjugate division (CCD) without frequency domain analysis, and reduces computational effort by selecting CCDs with robust harmonic features using an energy indicator. The numerical, experimental, and field test results demonstrate the effectiveness of the RSP method in accurately identifying modal parameters under mixed random and harmonic excitation.
JOURNAL OF SOUND AND VIBRATION
(2023)
Article
Engineering, Multidisciplinary
Pengcheng Wang, Jun Chen
Summary: Modal mass is a critical modal parameter that is difficult to obtain accurately from identification methods in structural modal testing. This study proposes a method using pressure insoles to measure human-induced loads and an iterative correction method to identify the floor 1st-order modal mass from resonant responses. The method iteratively calculates the modal mass by weighting the errors between the calculated and measured multi-point acceleration responses Fourier spectrum and correcting the natural frequency and damping ratio. Applying the method to two prestressed concrete floors resulted in a maximum identification error of 6%, providing a convenient and accurate way to obtain floor modal mass.
Article
Engineering, Civil
Andrzej Katunin, Jose Viriato Araujo dos Santos, Hernani Lopes
Summary: This paper presents a novel damage identification approach based on differences in modal rotation fields obtained from shearographic measurements of structures and post-processed with the 2D continuous wavelet transform-based algorithm. It has been shown that the baseline approach improves the sensitivity of the method to damage, allowing for the identification of smaller damage compared to baseline-free methods. Additionally, a new method for reducing boundary effects and improving visualization of results maps has been introduced.
Article
Instruments & Instrumentation
E. Garutti, R. Klanner, E. Popova, S. Martens, J. Schwandt, C. Villalba
Summary: The main effect of radiation damage in a Silicon-Photomultiplier (SiPM) is an increase in the dark current. The SiPM's performance depends on temperature, which is affected by the power dissipated and heating. A KETEK SiPM was used to study the heating effect, with different thermal resistances. The method can be used to correct parameters for radiation-damaged SiPMs and packaged SiPMs with unknown thermal contact.
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT
(2022)
Review
Construction & Building Technology
Jin Luo, Minshui Huang, Yongzhi Lei
Summary: This paper presents a review of modal changes produced by environmental conditions and damage identification methods in civil engineering structures. The effects of temperature on vibration properties are discussed, as well as different research methods including experimental and theoretical studies.
Article
Engineering, Civil
Ge-Wei Chen, Piotr Omenzetter, Sherif Beskhyroun
Summary: The study evaluated the influence of different types of dynamic excitation sources on the modal parameter identification of an eleven-span, post-tensioned, curved concrete motorway off-ramp bridge. The natural frequency discrepancies across different excitation methods were small, while the consistency of the estimated damping ratios was poorer. Eccentric mass shaker testing enabled identification of all modes but used heavy equipment, while electrodynamic shaker testing missed only one mode and was easily portable on site.
ENGINEERING STRUCTURES
(2021)
Review
Acoustics
Zafer Yilmaz, Fatih Yesevi Okur, Murat Gunaydin, Ahmet Can Altunisik
Summary: This paper details the newly introduced method based on the calculation of modal participation ratio in damage detection and assessment. The method is evaluated for single-story and cumulative damage scenarios, and it is found that the variation in modal participation ratio can be used to detect the presence, severity, and location of damage.
JOURNAL OF VIBRATION AND CONTROL
(2023)
Article
Chemistry, Physical
Dmitry V. Makhov, Dmitrii V. Shalashilin
Summary: The research shows that pre-excitation of N-H bond vibrations facilitates fast direct dissociation, resulting in a significant increase in the high-energy wing of TKER spectra. The simulations are in good agreement with recent experimental results, indicating the specificity of this effect for N-H bond vibrations.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Acoustics
Tim Duerinck, Joost Segers, Ewa Skrodzka, Geerten Verberkmoes, Marc Leman, Wim Van Paepegem, Mathias Kersemans
Summary: This study provides a critical comparison of various experimental modal analysis approaches with the violin as a case study, considering both contact and non-contact excitation and different acquisition approaches. The influence of different boundary conditions on the vibrational response of the violin is investigated, and relevant modal parameters are extracted within the frequency range of 0-1000 Hz. Two optimal approaches for performing modal analysis on violins are proposed, one for use in the violinmaker's practice and one for use with fragile instruments.
Article
Engineering, Mechanical
Angel J. Molina-Viedma, Luis Felipe-Sese, Manuel Pastor-Cintas, Elias Lopez-Alba, Francisco A. Diaz
Summary: This study analyzes the adaptation of transmissibility functions to improve the accuracy of modal data estimation using vision techniques with conventional procedures. The adaptation significantly improves the accuracy of modal identification.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2022)
Article
Chemistry, Multidisciplinary
Chengjie Bai, Shi Li, Tong Chen, Xiaoxiao Chen, Wenjing Meng, Jie Pan
Summary: Through numerical investigation, this study examined the effects of inert gas dilution on methane-air NRP discharge plasma ignition process and related reaction mechanisms, showing that the addition of inert gases significantly reduces ignition delays.
Article
Engineering, Multidisciplinary
Andrzej Katunin, Ivanna Pivdiablyk, Laurent Gornet, Patrick Rozycki
Summary: This paper presents a hybrid method that combines fatigue limit evaluation with non-destructive evaluation to predict the behavior of composite structures with low-velocity impact damage. The results demonstrate the high sensitivity of the proposed method to impact damage and its ability to evaluate the fatigue life of tested structures. Recommendations for measurement setup and testing parameters are also provided.
COMPOSITES PART B-ENGINEERING
(2022)
Article
Chemistry, Analytical
Sandris Rucevskis, Tomasz Rogala, Andrzej Katunin
Summary: Optimal sensor placement is crucial in monitoring structural health, balancing performance and cost. This study investigated the problem using a composite plate with simulated damage and applied different sensor placement methods. The proposed approach allowed precise damage detection with resource-saving benefits in both costs and computational time.
Article
Mechanics
Andrzej Katunin, Dominik Wachla, Paulo Santos, Paulo N. B. Reis
Summary: This study investigates the influence of hybridization on the fatigue limit of bio-composites made of flax, glass/flax, Kevlar/flax, and carbon/flax. The evaluation is done using the critical self-heating temperature and acoustic emission approaches, as well as microscopic characterization for analyzing fracture mechanisms. The results show that hybridization opens new possibilities for controlling the fatigue and fracture properties of composites, and the critical self-heating temperature determined during fatigue tests can serve as an alternative indicator of the fatigue limit of a composite structure, as justified by microscopic examination.
COMPOSITE STRUCTURES
(2023)
Article
Chemistry, Analytical
Duc Cong Nguyen, Marek Salamak, Andrzej Katunin, Michael Gerges
Summary: Diagnostic load testing is essential for predicting the health state and load capacity of structures. This research proposes an improved method to automatically calibrate the analytical model using field data. The updated model provides more accurate predictions of load limits.
Review
Polymer Science
Jafar Amraei, Andrzej Katunin
Summary: The self-heating effect is a catastrophic phenomenon that occurs in polymers and polymer-matrix composites (PMCs) under fatigue loading or vibrations. It results in temperature growth in these structures due to their low thermal conductivities, leading to thermal stress and fatigue failure. Therefore, understanding and minimizing the self-heating effect is crucial for practical applications.
Article
Chemistry, Analytical
Sandris Rucevskis, Tomasz Rogala, Andrzej Katunin
Summary: Monitoring damage in composites using vibration-based structural response is challenging due to the complexity of fracture mechanisms. Implementing a health monitoring system is also complex, considering uncertainties and constraints like measurement noise and changing environmental conditions. This study aims to develop a cost-effective data-driven approach to monitor damage in composites and validate it with tests on a physically implemented SHM system. By combining finite element models and laboratory experiments, the developed approach enables the implementation of a cost-effective SHM system with validated predictive performance.
Article
Materials Science, Composites
Aravind Premanand, Tomasz Rogala, Dominik Wachla, Jafar Amraei, Andrzej Katunin, Bilal Khatri, Michael Rienks, Frank Balle
Summary: Conventional VHCF testing is time-consuming and impractical for large sample sizes. This study investigates the fatigue strength of a CF/PEKK composite by estimating its temperature evolution during 3-point bending tests at 20 kHz with different cyclic load amplitudes. The results demonstrate a reliable and rapid method for estimating fatigue life as a material property.
COMPOSITES SCIENCE AND TECHNOLOGY
(2023)
Article
Engineering, Mechanical
Andrzej Katunin, Wojciech Danek, Angelika Wronkowicz, Krzysztof Dragan
Summary: In this paper, a hybrid methodology is proposed to evaluate the residual strength of composite structures by using ultrasonic non-destructive testing technique, numerical modeling, and compression after impact (CAI) tests. This method can effectively predict the residual strength of composite materials while considering the complex geometrical shapes and fracture mechanisms of composites.
INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
(2023)
Article
Engineering, Multidisciplinary
Andrzej Katunin, Krzysztof Lis, Kamil Joszko, Pawel Zak, Krzysztof Dragan
Summary: This paper proposes an enhancement to the D-Sight non-destructive testing technique by allowing quantification of hidden corrosion in metallic aircraft fuselages. The approach involves image processing to quantify the spatial dimensions of corroded areas from D-Sight images, and finite element modeling to determine corrosion depth and degree. Validations were conducted using metrological measurements and digital image correlation techniques, correcting for overestimation typical of the D-Sight technique. The results provide a lower bound for the detectability of hidden corrosion using D-Sight, improving inspections of aircraft structures where this remains a serious and unresolved issue.
Article
Chemistry, Analytical
Andrzej Katunin, Piotr Synaszko, Krzysztof Dragan
Summary: In this paper, the authors introduced a new approach to automatically quantify hidden corrosion based on image processing D-Sight images during periodic inspections. The developed processing algorithm was shown to effectively evaluate the extent and progression of hidden corrosion and aligned with the results of qualitative analysis by inspectors. This enables the automation of the inspection process and supports inspectors in assessing hidden corrosion.
Article
Chemistry, Analytical
Andrzej Katunin, Marko Nagode, Simon Oman, Adam Cholewa, Krzysztof Dragan
Summary: This study proposed a method to monitor hidden corrosion growth in metallic aircraft structures using a sequence of D-Sight images, by analyzing the images through geometric transforms and segmentation techniques to eliminate the influence of measurement conditions.
Proceedings Paper
Construction & Building Technology
Andrzej Katunin, Angelika Wronkowicz-Katunin, Wojciech Danek, Krzysztof Dragan, Marek Wylezol
Summary: This study presents an approach based on reverse engineering to evaluate the structural residual life of composite elements affected by low-velocity impact loading. By combining non-destructive testing and numerical simulations, the geometric properties of damage were determined, and computer-aided design models were developed to predict the structural response.
4TH INTERNATIONAL CONFERENCE ON STRUCTURAL INTEGRITY (ICSI 2021)
(2022)
Proceedings Paper
Construction & Building Technology
Andrzej Katunin, Sandris Rucevskis
Summary: This paper analyzes and compares two different approaches (damage indices and curvelet transform) for damage identification in composite plates and evaluates their sensitivity to damage, robustness to measurement and processing noise, and accuracy of damage estimation. The results clearly indicate the superiority of the curvelet transform, which not only accurately identifies damage with enhanced directional selectivity but also reduces measurement noise, making it an excellent choice for effective damage identification in various engineering structures.
4TH INTERNATIONAL CONFERENCE ON STRUCTURAL INTEGRITY (ICSI 2021)
(2022)
Proceedings Paper
Construction & Building Technology
Tomasz Rogala, Piotr Przystalka, Andrzej Katunin
Summary: Due to the automation of industrial processes, intelligent decision-making tools are in high demand in various industries, including non-destructive evaluation. This paper presents a preliminary study on a damage classification algorithm based on deep neural networks, which aims to classify different types of structural damage in composites using X-ray computed tomography scans. The results demonstrate the effectiveness of the proposed approach and provide a pathway for further algorithm development.
4TH INTERNATIONAL CONFERENCE ON STRUCTURAL INTEGRITY (ICSI 2021)
(2022)
Article
Mechanics
Rawan Aqel, Patrick Severson, Rani Elhajjar
Summary: A novel core splice joint configuration for composite sandwich structures is studied and proposed to improve the strength and toughness. Experimental and numerical efforts show that this configuration can significantly increase the ultimate strength by 13% to 51% and the toughness by 2% to 35%.
COMPOSITE STRUCTURES
(2024)
Article
Mechanics
Xianheng Wang, Cong Chen, Jinsong Zhang, Xinming Qiu
Summary: In this paper, a new form-finding method based on spatial elastica model (FMSE) is proposed for elastic gridshells. The method integrates the deformations of elastic rods into the overall deformation of the gridshell, and solves a set of transcendental equations using the quasi-Newton method to ensure the deformation satisfies the given boundary conditions. The method is validated through experiments and expected to have potential applications in the investigations of elastic gridshells.
COMPOSITE STRUCTURES
(2024)
Article
Mechanics
Hao Huang, Zitong Guo, Zhongde Shan, Zheng Sun, Jianhua Liu, Dong Wang, Wang Wang, Jiale Liu, Chenchen Tan
Summary: The conventional evaluation of 3D braided composites' mechanical properties through numerical and experimental methodologies hinders material application due to the expenses, time constraints, and laborious efforts involved. This study establishes a multi-scale finite element model and a surrogate model for predicting the elastic properties of 3D4D rotary braided composites with voids. By optimizing a neural network model, the results are validated and provide valuable insights into the microstructure and properties of these composites.
COMPOSITE STRUCTURES
(2024)
Article
Mechanics
Xinyu Li, Hao Zhang, Haiyang Yang, Junrong Luo, Zhongmin Xiao, Hongshuai Lei
Summary: Due to their excellent mechanical properties and design flexibility, fluted-core composite sandwich structures have gained significant attention in aerospace and rail transit applications. This study investigated the free-vibration characteristics and optimized design of composite fluted-core sandwich cylinders through theoretical models and experimental tests.
COMPOSITE STRUCTURES
(2024)
Article
Mechanics
Chao Li, Chunzheng Duan, Xiaodong Tian, Chao Wang
Summary: A mechanistic model considering the bottom edge cutting effect and the anisotropic characteristics of the material is proposed in this paper to accurately predict cutting forces. The model was validated through a series of milling experiments and can be used to predict the cutting force of various parts of the cutter and any feed direction.
COMPOSITE STRUCTURES
(2024)
Article
Mechanics
Camila Sanches Schimidt, Leopoldo Pisanelli Rodrigues de Oliveira, Carlos De Marqui Jr
Summary: This work investigates the vibro-acoustic performance of graded piezoelectric metamaterial plates. The study shows that piezoelectric metamaterial plates with reconfigurable properties can provide enhanced vibration and sound power attenuation.
COMPOSITE STRUCTURES
(2024)
Article
Mechanics
Jun Ke, Li-jie Liu, Zhen-yu Wu, Zhong-ping Le, Luo Bao, Dong-wei Luo
Summary: Compared with other green natural fibers, ramie has higher mechanical properties and lower cost. In this study, ramie and glass fiber are made into composite circular tubes. The results show that the hybrid circular tube with ramie and glass fiber has improved torsional mechanical properties and reduced weight and cost. The failure mechanisms are affected by the loading direction and the content of each fiber.
COMPOSITE STRUCTURES
(2024)
Article
Mechanics
Natalia Pingaro, Gabriele Milani
Summary: This paper proposes an enhanced analytical model for predicting the behavior of FRCM samples tested under standard tensile tests. The model takes into account the interaction between fibers and matrix through the interface, and assumes different material properties at different phases. By solving a second order linear differential equation, an analytical solution can be obtained. The model is validated with experimental data and shows good predictability.
COMPOSITE STRUCTURES
(2024)
Article
Mechanics
Jialiang Fan, Anastasios P. Vassilopoulos, Veronique Michaud
Summary: This article investigates the effects of voids, joint geometry, and test conditions on the fracture performance of thick adhesive Double Cantilever Beam (DCB) joints. It concludes that grooved DCB joints with low void content tested at low displacement rates showed stable crack propagation without significant crack path deviation.
COMPOSITE STRUCTURES
(2024)
Article
Mechanics
Auwalu I. Mohammed, Kaarthikeyan Raghupathy, Osvaldo De Victoria Garcia Baltazar, Lawson Onokpasah, Roger Carvalho, Anders Mogensen, Farzaneh Hassani, James Njuguna
Summary: This study investigates the performance of composite pressure vessels under damaged and undamaged conditions, providing insights into their reliability and residual strength capabilities. The results demonstrate that the damage profile and its effect on compressive strength are similar between damaged and non-damaged cylinders. When subjected to quasi-static compression, the polyethylene liner absorbs enough elastic strain energy to recover without plastic deformation. Additionally, quasi-static compression has little to no influence on the axial strength of the cylinders. The damage characterization reveals fiber breakage, delamination, local buckling, and brooming failure. This study has direct implications for the safety design tolerances, manufacturing strategies, and operational failure conditions of composite overwrapped pressure vessels (COPVs).
COMPOSITE STRUCTURES
(2024)
Article
Mechanics
Muhammad Irfan Shirazi, Samir Khatir, Djilali Boutchicha, Magd Abdel Wahab
Summary: Structural health monitoring is important to ensure the safety of components and structures. This study proposes a method using finite element models and 1D-CNN network to extract and classify vibration responses for crack detection. The results show that the proposed approach is effective in real-time damage detection.
COMPOSITE STRUCTURES
(2024)
Article
Mechanics
Maryam Mirsalehi, Kiarash Kianpour, Sharif Shahbeyk, Mohammad Bakhshi
Summary: This study comprehensively investigates the one-way response of 3D-woven sandwich panels (3DWSPs) and their interfering parameters, providing interpretation of elastic and failure results, failure maps, and reliable theoretical models for linear elastic response and observed failure mechanisms.
COMPOSITE STRUCTURES
(2024)
Article
Mechanics
Yiming Zhao, Zhonggang Wang, Zhigang Yang, Bin Qin
Summary: The paper proposes a Ritz and statistical energy analysis (Ritz SEA) hybrid method for calculating rectangular plate acoustic vibration coupling in the mid-frequency range. This method combines the fast convergence and ability to handle arbitrary boundary conditions of the Ritz method with the power flow equation of the statistical energy analysis method. The results show that this approach effectively filters out random fluctuations in mid-frequency domains while demonstrating exceptional stability and precision.
COMPOSITE STRUCTURES
(2024)
Article
Mechanics
Joao Henrique Fonseca, Woojung Jang, Dosuck Han, Naksoo Kim, Hyungyil Lee
Summary: This study addresses the enhancement of an injection-molded fiber-reinforced plastic / metal hybrid automotive structure and its plastic injection molding process through the integration of the finite element method, artificial intelligence, and evolutionary search methods. Experimental validation of finite element models, the generation of a database through orthogonal array and Latin hypercube methods, and the training of artificial neural networks are conducted. The genetic optimization algorithm is then applied to identify optimal process parameters. The results show significant reduction in product warpage and manufacturing time while maintaining structural strength, contributing to the advancement of composite automotive structures with superior quality.
COMPOSITE STRUCTURES
(2024)
Article
Mechanics
Alessandro Vescovini, Carina Xiaochen Li, Javier Paz Mendez, Bo Cheng Jin, Andrea Manes, Chiara Bisagni
Summary: This paper presents a study on six single-stringer specimens manufactured using the card-sliding technique with non-crimp fabrics and adopting a Double-Double (DD) stacking sequence. The specimens were tested under compression loading conditions to investigate post-buckling and failure in aerospace structures. Experimental results and numerical simulations were compared to analyze the behavior and failure modes of the specimens. The study found promising evidence of a viable solution to optimize aeronautical structures and enhance resistance to skin-stringer separation, particularly with the use of tapered flanges.
COMPOSITE STRUCTURES
(2024)