Searched for: author%3A%22Pahlavan%2C+Lotfollah%22
(1 - 14 of 14)
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Alkhateeb, S. (author), Riccioli, F. (author), Morales, Felipe Leon (author), Pahlavan, Lotfollah (author)
Offshore support structures and mooring systems are predominantly subject to corrosion and fatigue. These structures are typically covered with marine growth of various types. Conventional inspection methods for assessment of the structural integrity require access to the cleaned surface of these structures; however, the cleaning process is...
journal article 2023
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Scheeren, B. (author), Kaminski, M.L. (author), Pahlavan, Lotfollah (author)
This article presents an approach to identify naturally developed damage in low-speed bearings using waveform-similarity-based clustering of acoustic emissions (AEs) under fatigue loading. The approach is motivated by the notation that each recorded AE signal from a particular damage is defined by the convolution of the source signal, transfer...
journal article 2023
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Riccioli, F. (author), Huijer, A.J. (author), Grasso, Nicola (author), Rizzo, Cesare M. (author), Pahlavan, Lotfollah (author)
Measurement of transient pressure distribution on maritime structures is important for the assessment of the hydrodynamic loads applied. The commonly used pressure sensors are mostly bulky, need to be bolted to the structure, and/or only provide point-wise measurements. In this paper, an elastic matrix layer with a network of embedded...
journal article 2023
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Bani Mohammad Ali, Amir (author), Valizadeh Sotubadi, Saleh (author), Alimirzaei, Sajad (author), Ahmadi Najafabadi, Mehdi (author), Pahlavan, Lotfollah (author)
Composite structures in transportation industries have gained significant attention due to their unique characteristics, including high energy absorption. Non-destructive testing methods coupled with machine learning techniques offer valuable insights into failure mechanisms by analyzing basic parameters. In this study, damage monitoring...
journal article 2023
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Alimirzaei, Sajad (author), Ahmadi Najafabadi, Mehdi (author), Bani Mohammad Ali, Amir (author), Pahlavan, Lotfollah (author)
The aim of this research is to investigate the failure mechanisms of the filament-wound composite tubes under axial compressional loading by using an acoustic emission approach. First, the mechanical properties of ±45°C composite tubes were obtained experimentally. Then, failure due to the buckling phenomenon and crashworthiness...
journal article 2023
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Alimirzaei, Sajad (author), Ahmadi Najafabadi, Mehdi (author), Nikbakht, Ali (author), Pahlavan, Lotfollah (author)
By analyzing the failure mechanisms, crashworthiness characteristics of FW composite tubes subjected to two modes of progressive damage and catastrophic failure are investigated using acoustic emission technique and numerical method. The AE signals of ±45° composite tubes were classified using hierarchical and wavelet transform methods, and...
journal article 2023
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Scheeren, B. (author), Kaminski, M.L. (author), Pahlavan, Lotfollah (author)
In the condition monitoring of bearings using acoustic emission (AE), the restriction to solely instrument one of the two rings is generally considered a limitation for detecting signals originating from defects on the opposing non-instrumented ring or its interface with the rollers due to the signal energy loss. This paper presents an approach...
journal article 2022
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Huijer, A.J. (author), Zhang, X. (author), Kassapoglou, C. (author), Pahlavan, Lotfollah (author)
Marine propellers made of fibre-reinforced composites have demonstrated the potential to outperform metallic propellers in terms of efficiency and under-water noise radiation. For full realisation of this potential in a tailored design process with realistic constraints, accurate information on the hydrodynamic loads acting on composite...
journal article 2022
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Huijer, A.J. (author), Kassapoglou, C. (author), Pahlavan, Lotfollah (author)
The recording and processing of acoustic emissions can be used to identify and localise damage mechanisms occurring in engineering structures. In plate-like structures, acoustic emissions propagate through the structure as guided waves. With a measurement location away from the source location, dispersion effects in the guided wave distort...
conference paper 2022
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Alimirzaei, Sajad (author), Najafabadi, Mehdi Ahmadi (author), Nikbakht, Ali (author), Pahlavan, Lotfollah (author)
The focus of this study is to investigate the mechanical properties, of ±35° and ±55° filament wound (FW) composite tubes under axial compression loading using the acoustic emission technique. For this purpose, material failure, crashworthiness characteristics, and the effect of each mechanism on the energy absorption capacity were studied...
journal article 2022
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Scheeren, B. (author), Pahlavan, Lotfollah (author)
This study presents an approach for the detection of evolving degradation in large-scale low-speed roller bearings by clustering of Acoustic Emission (AE) events, and its application to experimental degradation data. To acquire the latter, a purpose-built linear bearing, representative of a segment of a turret bearing, has been instrumented with...
conference paper 2022
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Huijer, A.J. (author), Kassapoglou, C. (author), Pahlavan, Lotfollah (author)
Piezoelectric sensors can be embedded in carbon fibre-reinforced plastics (CFRP) for continuous measurement of acoustic emissions (AE) without the sensor being exposed or disrupting hydro- or aerodynamics. Insights into the sensitivity of the embedded sensor are essential for accurate identification of AE sources. Embedded sensors are considered...
journal article 2021
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Zhang, F. (author), Pahlavan, Lotfollah (author), Yang, Y. (author)
Acoustic emission source localization is a promising monitoring technique for concrete structures. However, the accuracy of acoustic emission source localization is influenced by many factors, such as the presence of cracks, which are commonly observed in existing reinforced concrete structures. In this article, the acoustic emission source...
journal article 2020
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Scheeren, B. (author), Pahlavan, Lotfollah (author), Kaminski, M.L. (author)
In the present study, feasibility of implementing an acoustic emission (AE) system for condition monitoring of highly-loaded and low-speed roller bearings has been quantitatively investigated. To evaluate the transmission of damage-induced AE signals inside the bearing and their detectability on the accessible surfaces, stress wave propagation...
conference paper 2018
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