Article
Engineering, Marine
Mengmeng Han, Chien Ming Wang
Summary: A combined floating breakwater-windbreak has been proposed to protect fragile coastlines and assets during extreme storms. Experimental results show that the porous breakwater hull can reduce wave reflection, increase wave dissipation, and effectively mitigate wave erosion.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2022)
Article
Mechanics
Ayan Chanda, Satyajit Pramanik
Summary: Porous breakwaters can be used to reduce wave impact on marine structures and dissipate wave energy, making them useful for creating artificial breeding or nursing grounds for marine animals. This study used linear potential flow theory to investigate water wave scattering by a surface-piercing porous breakwater with a vertical porous barrier. Analytical solutions were obtained using the eigenfunction expansion method, and the effects of various parameters on wave reflection, transmission, dissipation, and force were studied. The critical wave inclination angle, below which wave reflection is minimized and wave energy dissipation is maximized, has practical implications for harnessing energy from ocean waves and designing efficient breakwaters.
Article
Mathematics
Zine El Abiddine Fellah, Mohamed Fellah, Nicholas O. Ongwen, Erick Ogam, Claude Depollier
Summary: This paper presents a fractal model for acoustic propagation in porous materials with a rigid structure, modeling the medium as a continuous medium of non-integer spatial dimension. The fluid-structure interactions are described by fractional operators, and the resulting propagation equation contains fractional terms. Solutions in the time domain show that it is possible to deduce responses in fractal porous media by replacing the thickness of non-fractal materials with an effective thickness based on the fractal dimension. The results open up possibilities for the creation of new acoustic materials with unique properties.
Article
Engineering, Marine
Chun Yang, Alexey Stovas, Yun Wang, Liheng Wang
Summary: This article studies the reflection and transmission of acoustic waves in ocean sediments and proposes a more concise formula for the reflection and transmission coefficients. By establishing the propagator matrix of the coupled water-porous-layer-solid elastic system, the method for calculating the displacement reflection and transmission coefficients for P-wave incidence cases is provided.
Article
Engineering, Multidisciplinary
Sonam Singh, A. K. Singh, Sayantan Guha
Summary: The study focuses on the reflection and transmission of plane waves at imperfect interfaces between two different Porous-Piezoelectric(PPE) half-spaces. Different interface conditions were studied for their effects on the reflection and transmission phenomenon.
APPLIED MATHEMATICAL MODELLING
(2021)
Article
Materials Science, Composites
Tianyu Gao, Kai Liu, Xinxin Wang, Lumin Shen, Yiming Zhao, Kai Wei, Zhonggang Wang
Summary: In this study, a smooth-transition hybrid TPMS with multi-functional characteristics is designed to improve the performance of conventional hybrid materials in shock absorption and noise reduction. The smooth hybrid intervals provide desirable transmission and reflection of stress wave conforming to the impedance characteristics of each component. Furthermore, the air domains in TPMS structure expand the high-frequency acoustic isolation properties. The mechanics-acoustics coupling property of proposed hybrid TPMS may have significant implications for the development of novel shock absorption and noise reduction materials.
COMPOSITES COMMUNICATIONS
(2023)
Article
Materials Science, Multidisciplinary
Shishir Gupta, Sandip Kumar Das, Snehamoy Pramanik
Summary: This article discusses the behavior of reflection/transmission phenomena on the propagation of SH waves in a corrugated fluid-saturated porous layer sandwiched between heterogeneous viscoelastic and orthotropic half-spaces. Mathematical tools and numerical treatments were used to analyze the effect of various parameters, and the conservation of energy rule was found to hold well in the model. The findings may be valuable in enhancing knowledge about the structure of rock in the Earth's interior and its elastic property in the field of seismology and geophysics.
MECHANICS OF ADVANCED MATERIALS AND STRUCTURES
(2022)
Article
Engineering, Marine
Uma Vinod Kumar, Sunanda Saha, Swaroop Nandan Bora
Summary: Scattering of oblique waves by a system consisting of a thin floating porous-elastic plate and a rectangular submerged porous structure is investigated. The study reveals that plate porosity, along with variation in height and width of the system have a significant impact on scattering and mitigation of wave forces.
Article
Mechanics
N. M. Prasad, R. B. Kaligatla, S. Tabssum
Summary: The study investigates oblique wave scattering and wave trapping by a breakwater consisting of a series of thin porous walls in a two-layer ocean. Mathematical methods are used to analyze the effects of porous walls and bottom configurations on wave interaction, as well as wave forces on porous walls and seawalls. The findings may be useful for coastal engineers to understand wave scattering by multiple porous structures in the stratified ocean.
Article
Engineering, Civil
Cancan Liu, Jiangong Yu, Xianhui Wang, Bo Zhang, Xiaoming Zhang, Hongmei Zhou
Summary: A novel nonlocal stress expansion method is proposed to study the elastic wave propagation through piezoelectric nanoplates sandwiched in two solid half-spaces, without utilizing the relationship between local and nonlocal stress. The results show that the nonlocal effect reconstructs the wave mode conversion and enhances the influence of piezoelectricity on the critical angle.
THIN-WALLED STRUCTURES
(2021)
Article
Engineering, Ocean
S. Singla, H. Behera, S. C. Martha, T. Sahoo
Summary: This study investigates the effectiveness of a porous box in attenuating the structural response of a very large floating structure (VLFS). The results show that a porous box with moderate values of the porous-effect parameter can reduce strain and shear force on the VLFS, as well as the amplitude on the lee side of the structure.
JOURNAL OF OFFSHORE MECHANICS AND ARCTIC ENGINEERING-TRANSACTIONS OF THE ASME
(2022)
Article
Engineering, Mechanical
Anjan Sasmal, Soumen De
Summary: A solution to the problem of wave interaction with multiple flexible porous barriers is presented using the Galerkin approximation technique in deep water. The study has analyzed the reflection coefficient, dissipated energy, and wave forces on the barriers and presented results for different inclination angles, separation lengths, porosity, and flexural rigidity of the barriers. The comparison of the results with those available in the literature adds credibility to the study. The finding that the flexural rigidity of the porous barriers has a significant effect on wave reflection, dissipated energy, and wave forces is an important contribution to the field. The observation that an increase in the number of barriers reduces the wave load significantly is also noteworthy. Overall, this study provides valuable insights into the behavior of wave interaction with multiple flexible porous barriers, which could have practical implications for coastal protection and wave energy conversion systems.
JOURNAL OF FLUIDS AND STRUCTURES
(2023)
Article
Acoustics
Pengxin Tao, Yang Liu, Jingtao Du, Zhigang Liu
Summary: A unified wave-based model is established in this paper for the in-plane vibration analysis of multiple coupled beams. It can not only analyze the vibration characteristics of complex coupled beams, but also reveal how waves are reflected and transmitted in the structure.
JOURNAL OF VIBRATION AND CONTROL
(2023)
Article
Mechanics
Sayantan Guha, Abhishek Kumar Singh
Summary: This article analytically studies the effects of different types of imperfect interfaces, normal and shear initial stresses, and rotation on the reflection and transmission characteristics of plane waves in two dissimilar piezothermoelastic fiber reinforced composite (PTFRC) half-spaces. The PTFRC structure is modeled using the Strength of Materials (SM) technique with the Rule of Mixtures (RM) approach. Numerical studies are conducted on two distinct PTFRCs comprised of CdSe-epoxy combination and PZT-5A-epoxy combination, showing the influences of incident angle, imperfect interfaces, rotation, varying magnitudes of normal and shear initial stresses, and thermal relaxation parameters on energy ratios.
EUROPEAN JOURNAL OF MECHANICS A-SOLIDS
(2021)
Article
Physics, Applied
Xiao Li, Daxing Dong, Jiaqing Liu, Youwen Liu, Yangyang Fu
Summary: In this work, an acoustic metagrating (MG) with perfect retroreflection is realized using an inverse-design scheme, improving upon the limited efficiency of previous designs. The study also highlights the importance of evanescent guided modes in achieving perfect retroreflection, and identifies an orthogonal relationship between the contribution ratios of odd and even guided modes.
APPLIED PHYSICS LETTERS
(2022)
Article
Engineering, Marine
Alba Ricondo, Laura Cagigal, Beatriz Perez-Diaz, Fernando J. Mendez
Summary: This research presents a site-specific metamodel based on the SWASH numerical model simulations, which can predict coastal hydrodynamic variables in a fast and efficient manner. The metamodel uses downscaled and dimensionality reduced synthetic database to accurately reproduce wave setup, wave heights associated with different frequency bands, and wave runup. This method has great potential in coastal risk assessments, early warning systems, and climate change projections.
Article
Engineering, Marine
Xiao Yu, Wangjun Ren, Bukui Zhou, Li Chen, Xiangyun Xu, Genmao Ren
Summary: This study investigated and compared the compression responses and energy absorption capacities of coral sand and silica sand at a strain rate of approximately 1000 s-1. The results showed that coral sand had significantly higher energy absorption capacity than silica sand due to its higher compressibility. The study findings suggest that using poorly graded coral sand can improve its energy absorption capacity.
Article
Engineering, Marine
Jingxi Zhang, Junmin Mou, Linying Chen, Pengfei Chen, Mengxia Li
Summary: This paper proposes a cooperative control scheme for ship formation tracking based on Model Predictive Control. A predictive observer is designed to estimate the current motion states of the leader ship using delayed motion information. Comparative simulations demonstrate the effectiveness and robustness of the proposed controller.
Article
Engineering, Marine
Yu Yao, Danni Zhong, Qijia Shi, Ji Wu, Jiangxia Li
Summary: This study proposes a 2DH numerical model based on Boussinesq equations to investigate the impact of dredging reef-flat sand on wave characteristics and wave-driven current. The model is verified through wave flume experiments and wave basin experiments, and the influences of incident wave conditions and pit morphological features on wave characteristics are examined.
Article
Engineering, Marine
Jayanta Shounda, Krishnendu Barman, Koustuv Debnath
Summary: This study investigates the double-average turbulence characteristics of combined wave-current flow over a rough bed with different spacing arrangements. The results show that a spacing ratio of p/r=4 offers the highest resistance to the flow, and the double-average Reynolds stress decreases throughout the flow depth. The advection of momentum-flux of normal stress shows an increase at the outer layer and a decrease near the bed region after wave imposition. Maximum turbulence kinetic energy production and diffusion occur at different layers. The turbulence structure is strongly anisotropic at the bottom region and near the outer layer, with a decrease in anisotropy observed with an increase in roughness spacing.
Article
Engineering, Marine
Meng Zhang, Lianghui Sun, Yaoguo Xie
Summary: The research proposes a method for online identification of wave bending and torsional moment in hull structures. For structures without large openings, the method optimizes sensor positions and establishes a mathematical model to improve accuracy. For structures with large openings, a joint dual-section monitoring method is proposed to simultaneously identify bending and torsional moments in multiple key cross sections.
Article
Engineering, Marine
Longming Chen, Shutao Li, Yeqing Chen, Dong Guo, Wanli Wei, Qiushi Yan
Summary: This study investigated the dynamic response characteristics and damage modes of pile wharves subjected to underwater explosions. The results showed that the main damaged components of the pile wharf were the piles, and inclined piles had a higher probability of moderate or more significant damage compared to vertical piles. The study also suggested that replacing inclined piles with alternative optimized structures benefits the blast resistance of pile wharves.
Article
Engineering, Marine
I. -C Kim, G. Ducrozet, V. Leroy, F. Bonnefoy, Y. Perignon, S. Bourguignon
Summary: Previous research focused on the accuracy and efficiency of short-term wave fields in specific prediction zones, while we developed algorithms for continuous wave prediction based on the practical prediction zone and discussed important time factors and strategies to reduce computational costs.
Article
Engineering, Marine
Hang Xie, Xianglin Dai, Fang Liu, Xinyu Liu
Summary: This study investigates the load characteristics of a three-dimensional stern model with pitch angle through a drop test, and reveals complex characteristics of pressure distribution near the stern shaft. The study also shows that the vibration characteristics of the load are influenced by the drop height and pitch angle, with the drop height having a greater effect on the high-frequency components.
Article
Engineering, Marine
Hangyuan Zhang, Wanli Yang, Dewen Liu, Xiaokun Geng, Wangyu Dai, Yuzhi Zhang
Summary: The deep-water bridge is more vulnerable to earthquake damage than the bridge standing in air. The larger blocking ratio has a significant impact on the added mass coefficient, which requires further comprehensive study. The generation mechanism of block effect is analyzed using numerical simulation software ANSYS Fluent. The results show that the recirculation zone with focus reduces the pressure on the back surface of the cylinder, resulting in the peak value of in-line force not occurring synchronously with the peak value of acceleration. The change in position and intensity of the recirculation zone with focus, as well as the change in water flow around the cylinder surface, are identified as the generation mechanism of the block effect, which has a 10% influence on the hydrodynamic force. The changing rule of the added mass coefficient with blocking ratio is discussed in detail, and a modification approach to the current added mass coefficient calculation method is suggested. Physical experiments are conducted to validate the modification approach, and the results show that it is accurate and can be used in further study and real practice.
Article
Engineering, Marine
Golnesa Karimi-Zindashti, Ozgur Kurc
Summary: This study examines the performance of an in-house code utilizing a deterministic vortex method on the rotation of circular and square cylinders. The results show that rotational motion reduces drag forces, suppresses fluctuating forces, and increases lift forces. The code accurately predicts vortex shedding suppression and identifies the emergence of near-field wakes in the flow over rotating square cylinders.
Article
Engineering, Marine
George Dafermos, George Zaraphonitis
Summary: The survivability of damaged ships is of great importance and the regulatory framework is constantly updated. The introduction of the probabilistic damage stability framework has rationalized the assessment procedure. Flooding simulation tools can be used to investigate the dynamic response of damaged ships.
Article
Engineering, Marine
Xuyue Chen, Xu Du, Chengkai Weng, Jin Yang, Deli Gao, Dongyu Su, Gan Wang
Summary: This paper proposes a real-time drilling parameters optimization method for offshore large-scale cluster extended reach drilling based on intelligent optimization algorithm and machine learning. By establishing a ROP model with long short-term memory neurons, and combining genetic algorithm, differential evolution algorithm, and particle swarm algorithm, the method achieves real-time optimization of drilling parameters and significantly improves the ROP.
Article
Engineering, Marine
Sung-Jae Kim, Chungkuk Jin, MooHyun Kim
Summary: This study investigates the dynamic behavior of a moored submerged floating tunnel (SFT) under tsunami-like waves through numerical simulations and sensitivity tests. The results show that design parameters significantly affect the dynamics of the SFT system and mooring tensions, with shorter-duration and higher-elevation tsunamis having a greater impact.
Article
Engineering, Marine
G. Clarindo, C. Guedes Soares
Summary: Environmental contours are constructed using the Inverse-First Order Reliability Method based on return periods. The paper proposes the use of the Burr distribution to model the marginal distribution of long-term significant wave heights. The newly implemented scheme results in different environmental contours compared to the reference approach.