Article
Construction & Building Technology
Nakisa Mansouri Nejad, Seyed Bahram Beheshti Aval, Mohammad Maldar, Behrouz Asgarian
Summary: With the help of Structural Health Monitoring methods, damage can be identified early on to prevent fatalities and financial losses. The combination of signal processing techniques and machine learning tools has led to significant progress in achieving this goal. Experimental results show that Discrete Wavelet Transform is a more reliable method for damage detection compared to Empirical Mode Decomposition due to superior noise reduction capabilities.
ADVANCES IN STRUCTURAL ENGINEERING
(2021)
Article
Chemistry, Analytical
Liaqat Ali, Sikandar Khan, Salem Bashmal, Naveed Iqbal, Weishun Dai, Yong Bai
Summary: This paper successfully detected fatigue damage in T-joints of offshore steel jacket structures using a combination of experimental methods and finite element analysis. The results showed that fatigue cracks of different types of joints are prone to appear at the weld toe and spread in the welding direction.
Article
Environmental Sciences
Caiyun Huan, Dongzhe Lu, Shengxiao Zhao, Wenhua Wang, Jin Shang, Xin Li, Qingquan Liu
Summary: The dynamic characteristics and coupling mechanisms of jacket offshore wind turbines (OWTs) in the southeastern offshore regions of China have been extensively investigated using numerical simulation tools. An integrated scaled jacket OWT physical test model has been designed, and dynamic model tests under typical scaled wind fields have been implemented to study the coupling mechanisms.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Engineering, Marine
Hadi Moghaddam Nia, Ali Akbar Aghakouchak
Summary: This paper evaluates the accuracy of several methods for fatigue analysis of tubular joints in fixed offshore platforms. The results show that frequency domain methods generally provide conservative results, and the slope of the S-N curve has a significant impact on the results.
Article
Engineering, Marine
Hamid Hejazitalab, Touraj Taghikhany
Summary: This paper presents an intelligent signal processing-based system for damage detection in offshore jacket platforms. Two damage indicators based on signal's entropy and power are introduced for damage localization. An intelligent system combining artificial neural network and signal processing techniques is used for damage quantification. The proposed method achieves high accuracy in damage localization and severity detection on an offshore jacket platform in the Persian Gulf.
Article
Engineering, Ocean
Wen Chen, Chunbao Xiong, Lina Yu, Sida Lian, Zhuang Ye
Summary: This study proposed a two-step approach using RTK-GNSS technology to monitor the dynamic response of offshore platforms in real-time, with the CF-CEEMDAN filter to reduce background noise interference. Experimental results demonstrate that this method effectively improves monitoring accuracy and reduces noise interference.
APPLIED OCEAN RESEARCH
(2021)
Article
Engineering, Multidisciplinary
Saeed Khalaj, Farshad BahooToroody, Leonardo Leoni, Filippo De Carlo, Gianpaolo Di Bona, Antonio Forcina
Summary: The dynamic performance of an offshore jacket platform (OJP) subjected to harsh environmental conditions is evaluated using a time-domain simulation. A developed model simulates the entire structure subjected to extreme wave loading, resulting in a more realistic response. By assessing the performance of an OJP in the North Sea, it is shown that the structure remains within the safe limit condition in the 1-year return period.
MATHEMATICAL PROBLEMS IN ENGINEERING
(2022)
Article
Chemistry, Analytical
Zengyuan Liu, Xiujuan Feng, Chengliang Dong, Mingzhi Jiao
Summary: This paper proposes an analytical method of PID signal with the adaptive weight of small wave packet decomposition node to suppress noise caused by the photoionization detector monitoring signal of VOCs. The PID signal is transmitted to the upper machine software through a single-chip microcontroller. By comparing with traditional wavelet packet denoising method, the superiority of the proposed method in denoising signals of PID is verified. This method lays a foundation for accurate VOCs monitoring in a high humidity environment by eliminating noise generated by local non-uniformity on the photocathode surface of PID ionization chamber.
Article
Engineering, Civil
Anne S. Kiremidjian
Summary: This paper provides an overview of damage diagnosis algorithms that utilize vibration signals obtained from structures over the past two decades. The focus of the paper is on algorithms that can be used to identify structural damage following extreme events, such as earthquakes, in a timely manner. The algorithms utilize measurements from accelerometers and gyroscopes to identify and classify damage. Example algorithms include those based on ARMA, wavelet energies, and rotation models. The algorithms are demonstrated using data from test structures and laboratory tests. The paper concludes by highlighting the need for further research and development for these algorithms to be viable in practice.
SMART STRUCTURES AND SYSTEMS
(2022)
Article
Engineering, Biomedical
Mahesh Chandra, Pankaj Goel, Ankita Anand, Asutosh Kar
Summary: The improved high-speed adaptive filter-based denoising architectures proposed in this paper outperform existing adaptive filter architectures and wavelet-based architectures, offering design flexibility and efficiency in denoising ECG signals in noisy environments for low-cost high-performance applications in the medical field. These architectures also require significantly less hardware compared to state-of-the-art wavelet-based architectures.
BIOMEDICAL SIGNAL PROCESSING AND CONTROL
(2021)
Article
Engineering, Multidisciplinary
Claudia Barile, Caterina Casavola, Giovanni Pappalettera, Vimalathithan Paramsamy Kannan
Summary: Signal-based acoustic emission data were analyzed in this research to identify damage modes in CFRP composites. Novel methodologies were introduced, and the 'dmey' wavelet was chosen for damage process identification through WPT, which showed consistent results with shifting in spectral density for characterizing damage modes.
STRUCTURAL HEALTH MONITORING-AN INTERNATIONAL JOURNAL
(2022)
Article
Engineering, Marine
Alireza Asgari Motlagh, Naser Shabakhty, Ali Kaveh
Summary: This study optimized an offshore platform using a Genetic Algorithm, considering fatigue constraints, and found that optimization significantly reduced the structural weight of the platform.
Article
Engineering, Marine
Xingxian Bao, Tongxuan Fan, Chen Shi, Guanlan Yang
Summary: This study explores the use of one-dimensional convolutional neural network for automatically extracting damage sensitive features from raw strain response data of offshore structures, without requiring hand-crafted feature extraction. The method is validated through numerical simulations and experimental studies, showing excellent performance in structural damage detection.
Article
Engineering, Environmental
Xingxian Bao, Tongxuan Fan, Chen Shi, Guanlan Yang
Summary: This paper illustrates the application of deep learning methods in damage detection of offshore platforms. The study shows that deep learning methods have outstanding performance in structural damage detection, especially in noisy conditions.
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2021)
Article
Mechanics
Jie Wang, Wei Zhou, Xia-ying Ren, Ming-ming Su, Jia Liu
Summary: A real-time analytical approach for damage mode identification of carbon fiber reinforced polymer using machine learning and acoustic emission is proposed. Waveform features are extracted from acoustic emission signals using wavelet packet transform, and a waveform-based clustering model is constructed to reveal the relevance between acoustic emission signals and damage modes. Different types of composite laminates can be recognized by the developed softmax layer classifier.
COMPOSITE STRUCTURES
(2023)
Article
Engineering, Civil
Masoumeh Soltani, Behrouz Asgarian
INTERNATIONAL JOURNAL OF STRUCTURAL STABILITY AND DYNAMICS
(2019)
Article
Engineering, Civil
Mohamad Zarrin, Mohsen Abyani, Behrouz Asgarian
STRUCTURE AND INFRASTRUCTURE ENGINEERING
(2020)
Article
Engineering, Civil
Jong Wan Hu, Hamed Rahman Shokrgozar, Edris Salehi Golsefidi, Iman Mansouri
PERIODICA POLYTECHNICA-CIVIL ENGINEERING
(2020)
Article
Construction & Building Technology
Kazem Shakeri, Vahid Akrami, Hamed Rahman Shokrgozar, Amin Arden
Summary: Steel moment-resisting frames (MRFs) are designed to resist seismic events, but may collapse under the cyclic deterioration of structural elements during early earthquakes; exposure to foreshocks and aftershocks can significantly reduce structural collapse capacity.
PROCEEDINGS OF THE INSTITUTION OF CIVIL ENGINEERS-STRUCTURES AND BUILDINGS
(2022)
Article
Engineering, Marine
Azita Khosravan, Behrouz Asgarian, Hamed R. Shokrgozar
Summary: A new method for detecting structural damage of offshore platforms using a limited number of sensors has been developed, which simultaneously utilizes modal frequencies and mode shapes, as well as decomposes modal strain energy into axial and bending. The method has been evaluated experimentally and proven effective in detecting damages with incomplete data.
Article
Engineering, Marine
Hamed Rahman Shokrgozar, Behrouz Asgarian, Vahid Aghaeidoost
Summary: This paper introduces the experimental response of a prototype model under various damage scenarios, identifying damage locations using the signal energy decomposition approach. Overcoming weaknesses of other energy methods, this approach can predict all damages in a prototype with reasonable accuracy, making it a suitable method for structural health monitoring for steel jacket-type offshore platforms.
SHIPS AND OFFSHORE STRUCTURES
(2022)
Article
Engineering, Civil
Hamed Rahman Shokrgozar, Vahid Akrami, Tayebeh Jafari Ma'af, Naseraldin Shahbazi
Summary: This study investigated the remedial effects of using steel casing and CFRP sheets on the axial load carrying capacity of damaged steel cylindrical shells. Experimental results showed that both techniques improved the load-carrying behavior of damaged specimens. Numerical analysis focused on different parameters of the steel casing strengthening technique to determine their influence on efficacy, providing practical recommendations for selecting appropriate parameters.
Article
Construction & Building Technology
Seyed Bahram Beheshti Aval, Mohammad Maldar, Ehsan Darvishan, Bahareh Gholipour, Nakisa Mansouri Nejad, Behrouz Asgarian
Summary: A novel approach to damage detection based on dispersion analysis and signal processing methods is described in this study. The proposed method was applied on a scaled experimental model of a jacket-type offshore platform, and a forced vibration test was conducted to acquire the acceleration signals. The frequency spectrum of the first intrinsic mode function of the recorded signals was obtained using the Hilbert transform, revealing that damage caused dispersion in the extracted frequencies. A new damage index, based on the Mahalanobis distance dispersion of the HT frequency spectrum, was developed for accurate damage detection. The results demonstrate that the proposed index can accurately determine the location and severity of damage.
PROCEEDINGS OF THE INSTITUTION OF CIVIL ENGINEERS-STRUCTURES AND BUILDINGS
(2021)
Article
Construction & Building Technology
Vahid Aghaeidoost, A. H. M. Muntasir Billah
Summary: The goal of this research is to investigate the sensitivity of isolated bridges' seismic response using different modeling techniques for lead rubber bearings (LRBs). The study examines the effect of LRB modeling techniques on the nonlinear dynamic response and failure probability of two identical reinforced concrete bridges with curved and straight configurations. Different ground motion suites are considered, and three LRB modeling techniques available in OpenSees are used. The results show that the failure probability is significantly sensitive to the LRB modeling scheme as well as the ground motion type.
STRUCTURAL CONTROL & HEALTH MONITORING
(2022)
Article
Engineering, Civil
Vahid Aghaeidoost, A. H. M. Muntasir Billah
Summary: This study aims to evaluate the overall life-cycle resilience performance and post-seismic loss analysis of bridges equipped with two different isolation systems. The results show that seismic resilience, loss, and cost analysis are more sensitive to the type of ground motions, geometric shape of the bridge, and type of isolation bearings, respectively.
STRUCTURE AND INFRASTRUCTURE ENGINEERING
(2023)
Article
Engineering, Marine
V. Aghaeidoost, S. Afshar, N. Ziaie Tajaddod, B. Asgarian, H. Rahman Shokrgozar
Summary: This paper introduces an effective method for detecting structural damage through vibrational analysis and determining its location and severity. The proposed method utilizes the vibrational characteristics of the structure to deduce changes in its physical properties through sensor monitoring. A case study on a scaled model of a jacket-type offshore platform demonstrates the effectiveness of the method in accurately identifying the damage location and severity at varying levels of damage.
Article
Engineering, Civil
Mostafa Ghalami, Hamed Rahman Shokrgozar, Vahid Jahangiri, Mohamad Motamedi
Summary: This study evaluated and compared the efficiency of four passive energy dissipation means in high-rise building response, considering the effects of soil and foundation flexibility. The results show that metallic yielding and viscoelastic dampers have the best performance in reducing the structural responses.
INGEGNERIA SISMICA
(2022)
Article
Engineering, Civil
Hamed Rahman Shokrgozar, Maryam Zare Aghbolagh
INGEGNERIA SISMICA
(2020)
Article
Engineering, Marine
Chunhao Jiang, Lin Lin, Nian-Zhong Chen
Summary: A novel type of side structure for enhancing the crashworthiness of double-hull vessels is proposed based on auxetic materials. Numerical simulation demonstrates the resistance to collision of three different unit cells. A comparative study shows that the proposed side structures have superior energy absorption and collision resistance compared to traditional side structures.
Article
Engineering, Marine
Lihua Xu, Jiasong Wang, Michael S. Triantafyllou, Dixia Fan
Summary: This paper presents a data assimilation method based on the POD-DeepONet structure to fuse two types of fidelity data from vortex-induced vibration (VIV) problems. The POD-DeepONet structure provides better accuracy and more stable predictions for amplitude response, successfully capturing the changing trend with the oncoming flow speed. The exponentially fitted MSE formula allows for quick determination of the required case number under the expected error.
Article
Engineering, Marine
Ilias Gavriilidis, Aris G. Stamou, Christos Palagas, Efthimios Dourdounis, Nikos Voudouris, Athanasios Tazedakis, Spyros A. Karamanos
Summary: This study investigated the collapse resistance of thick-walled steel pipes fabricated with the JCO-E process for deep offshore applications. It conducted a comprehensive analysis using experimental, numerical, and analytical approaches to examine the effects of heat treatment on the collapse behavior of two JCO-E pipes. The results were compared with the predictions of the DNV-ST-F101 standard, and the fabrication factor afa was discussed. The study also explored the impact of yield strength recovery due to heat treatment on the collapse of pipes with different D/t ratios.
Article
Engineering, Marine
Sung-Jae Kim, Chungkuk Jin, MooHyun Kim
Summary: This study evaluates the effects of tsunami waves on the global performance of a spread-moored Floating Storage Unit (FSU) through tsunami-floater-mooring coupled dynamics simulations. The results show that larger tsunami heights and relatively short durations result in significantly increased motions and mooring tensions of the FSU.
Article
Engineering, Marine
Ling Zhu, Zhihui Zhou, Preben Terndrup Pedersen
Summary: Ship grounding experiments are crucial for validating numerical analysis and theoretical formulations. In this study, small-scale ship model grounding tests on a sharp rock were conducted in a water tank to observe and record different damage modes, ship bottom plate damage extents, and ship motion. The test results were used to analyze the energy dissipation process and the influence of initial conditions on ship response and damage.
Article
Engineering, Marine
Zhiping Zheng, Yanlin Shao, Jikang Chen
Summary: This study investigates the effect of horizontal low-frequency (LF) displacements and velocities on the responses of floating structures in irregular waves, focusing on a deep-draft spar buoy. The study finds that incorporating LF displacements and velocities in the seakeeping analysis is essential for reducing surge and pitch responses. The standard deviations of LF surge and pitch motions scale with significant wave height, highlighting viscous damping as the dominating damping mechanism.
Article
Engineering, Marine
Birendra Chaudhary, Hewenxuan Li, Akongnwi Nfor Ngwa, Helio Matos
Summary: This study investigates the long-term performance and effectiveness of coating systems for 3D-printed pressure vessels subjected to accelerated aging. The results show that the application of polyurethane coating systems significantly slows the degradation process, reducing critical operational depth and increasing pressure differential. This research contributes important insights into enhancing the longevity and performance of 3D-printed pressure vessels through coating systems.
Article
Engineering, Marine
Yuelin Song, Qin Dong, Jiping Zhang, Guoqiang Li, Dongfang Xu, Ping Yang
Summary: The objective of this research is to study the characteristics of low-cycle fatigue crack propagation from the perspective of accumulative plastic damage and propose a reliable prediction model for crack growth in EH-36 steel under high stress levels. Experimental findings demonstrate that increasing the mean stress and stress amplitude accelerates the progression of fatigue damage.
Article
Engineering, Marine
Hao Ding, Bo Huang, Liang Cheng, Ke Li, Qingyang Ren
Summary: This study investigates the dynamic response and cable forces of a submerged floating tunnel (SFT) under wave and wave-current interactions. Experimental results show that wave height, current velocity, and ratio of wavelength to structure size are important factors affecting the dynamic response of SFT and cable forces. The multi-anchor cable arrangement used in the experiments distributes cable forces more effectively and reduces potential safety hazards caused by cable breakage.
Article
Engineering, Marine
Baoshun Zhou, Zhixun Yang, Mostafa Amini-Afshar, Yanlin Shao, Harry B. Bingham
Summary: In the hydroelastic analysis of large floating structures, accurate prediction of response relies on the structural stiffness. However, obtaining exact structural stiffness is challenging due to the complexity of modern ship structures. This study proposes an efficient analysis technique that combines finite element and finite difference methods to calculate structural stiffness and solve hydrodynamic problems.
Article
Engineering, Marine
Xinwei Chen, Yang Yu, Lei Wang
Summary: This study introduces a framework to evaluate and compare scour prediction models, focusing on design robustness. By applying this framework, the study recommends the most favorable scour prediction model and optimal design for monopiles in OWTs.
Article
Engineering, Marine
Yu Lei, Wei Li, Xiang Yuan Zheng, Huadong Zheng, Shan Gao, Shengxiao Zhao
Summary: This paper compares the numerical results of a floating offshore wind turbine integrated with a steel fish farming cage (FOWT-SFFC) against experimental data. The study shows that the simulated responses are in good agreement with the experimental data and reveals the important influence of second-order wave forces on the simulation results.
Article
Engineering, Marine
Chenyu Luan, Torgeir Moan, Knut Andreas Kvale, Zhengshun Cheng
Summary: This paper deals with the study of the shear lag effect on the bending moment distribution in pontoon-type floating bridges. Comparative and parametric studies are carried out using beam and linear shell models to analyze the influence of shear lag on the bending stiffness and eigenmode shapes of the bridges. The study shows that elementary beam models may inaccurately predict the bending moments in bridges with large width and short span lengths, and a practical method is proposed to determine when caution is needed in using these models. The paper also highlights the complex boundary conditions near the bank abutment and the significant influence of shear lag on the bending moments in this region.
Article
Engineering, Marine
Akira Tatsumi, Yuji Kageyama
Summary: This study proposes a methodology to quantify the uncertainty of the ultimate strength of stiffened panels in steel ships and offshore structures due to the welding initial deflection. A statistical model of the initial deflection shape is developed based on measured data, and probability distributions of the ultimate strength are calculated using Monte Carlo simulation.
Article
Engineering, Marine
Zhenmian Li, Yang Yu, Xin Liu, Xiaowei Liu, Xiangyang Wang, Leige Xu, Jianxing Yu
Summary: This study evaluates the local collapses and propagating buckles of offshore pipelines under external overpressure, reverse fault displacements, and collapse failures. Different designs of integral arrestors are tested in a numerical model, and the effects of fault dip angles are investigated. The results show that integral arrestors are effective in preventing propagating buckles.
