Article
Engineering, Marine
Lin Lu, Huilong Ren, Hui Li, Jian Zou, Sangui Chen, Ruixiang Liu
Summary: This paper proposes a 3-D nonlinear time-domain hydroelastic analysis method for ship wave loads considering asymmetric slamming, using a 3-D Rankine panel method to solve the seakeeping problem. The interaction between the hull structure and the flow field is considered to accurately predict the hydroelastic response of the hull girder. By calculating asymmetric slamming loads using the Modified Logvinovich Model (MLM), the hydroelastic response of a 21,000-TEU container ship is analyzed, incorporating horizontal bending-torsional coupling vibration, and the mechanism of the slamming-whipping phenomenon is identified.
Article
Engineering, Mechanical
Zhongshu Ren, M. Javad Javaherian, Christine M. Gilbert
Summary: This study investigated the specific process and effects of hydroelastic slamming by vertically dropping a V-shaped wedge model with a 20-degree deadrise angle into calm water. It was found that the maximum deflection and strain occurred in the chine-unwetted phase of the wedge model. The kinematic effect of hydroelasticity altered spray root propagation, while the inertial effect increased the natural period of the plate.
JOURNAL OF FLUIDS AND STRUCTURES
(2021)
Article
Engineering, Mechanical
Jialong Jiao, Songxing Huang, C. Guedes Soares
Summary: The study utilized a two-way fluid structure interaction (FSI) numerical method combining CFD and FEA to predict ship motions, wave loads, and hydroelastic responses in regular waves. The results demonstrate that the method is reliable and capable of successfully reproducing ship responses in waves.
JOURNAL OF FLUIDS AND STRUCTURES
(2021)
Article
Engineering, Marine
Zhanyang Chen, Hongbin Gui, Xiyu Liao, Mengchao Du
Summary: This study introduces a three-dimensional nonlinear hydroelastic theory and conducts numerical simulations on the dynamic response of a flexible hull, comparing different methods and discussing their reasonable applicable conditions for structural design.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2021)
Article
Engineering, Marine
Haitao Li, Chi Zhang, Xinying Zheng, Zhiyuan Mei, Xuefei Bai
Summary: This paper introduces a simplified hull girder model to predict the whipping response of a vessel under an underwater explosion accurately and quickly. Structural and fluid damping effects on vessel dynamics are analyzed, and a theoretical model for elastic and elastic-plastic responses is verified using experimental data. Damping suppresses the whipping response and affects the plastic hinge rotation angle of the girder.
Article
Engineering, Marine
Konstantin Matveev
Summary: This study demonstrates the implementation of an air-cavity system on a shallow-draft hull using computational fluid dynamics modeling. The hull of a displacement barge-type air-cavity boat is numerically modified to operate at higher speeds, and computational simulations are conducted at various speeds and center of gravity positions.
Article
Engineering, Mechanical
Jose D. Mesa, Kevin J. Maki, Matthew T. Graham
Summary: This paper investigates high-speed aircraft ditching and marine-vessel slamming problems using numerical simulations and presents a validated numerical methodology. The results demonstrate the capability of accurately capturing complex water-entry phenomena, which are crucial for the design and certification of air, land, and watercraft.
JOURNAL OF FLUIDS AND STRUCTURES
(2022)
Article
Engineering, Mechanical
Bjorn C. Abrahamsen, Frode Grytten, Oyvind Hellan, Tore H. Soreide, Odd M. Faltinsen
Summary: This study focuses on the hydroelastic response of concrete shells in offshore structures when subjected to slamming loads. Due to the large size of the concrete columns, full scale tests are impractical, and model-scale testing is challenging. The study presents the design of realistic Froude scaled elastic shell models to represent concrete shells.
JOURNAL OF FLUIDS AND STRUCTURES
(2023)
Article
Engineering, Mechanical
Zhe Sun, A. Korobkin, X. P. Sui, Zhi Zong
Summary: This paper presents a semi-analytical model for hydroelastic slamming of two-dimensional symmetric flexible bodies, utilizing the Modified Logvinovich Model for computing hydrodynamic loads and considering elastic deflections of body surfaces. The model is validated for wedge and cylindrical shell water entry problems, showing significant improvements over the Wagner model in predicting deflections and stresses caused by impacts. The developed model is suitable for efficient and accurate computations of water elastic impacts.
JOURNAL OF FLUIDS AND STRUCTURES
(2021)
Article
Engineering, Marine
Jialong Jiao, Songxing Huang, Tahsin Tezdogan, Momchil Terziev, C. Guedes Soares
Summary: This study integrates CFD and FEA solvers to predict ship wave loads and slamming loads, taking hydroelastic effects into account. By comparing results using different mesh sizes and time step schemes, verification and sensitivity analysis of the wave loads and slamming pressures on a flexible ship are conducted. A simplified bow flare and bottom slamming pressure estimation method is proposed, based on seakeeping data of incident wave and ship global motions.
Article
Engineering, Marine
Zhe Sun, Xupeng Sui, Yanzeng Deng, Li Zou, A. Korobkin, Lixin Xu, Yichen Jiang
Summary: This paper studied the characteristics of impact pressure and force of a trimaran section through Computational Fluid Dynamics (CFD). It was found that the time domain features of slamming pressure or force were strongly correlated with penetration depth, regardless of water entry methods. The effects of velocity and acceleration on impact pressure and force were analyzed, showing that initial impact was mainly affected by entry velocities, while acceleration had little effect.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2021)
Article
Engineering, Ocean
Abhishek Acharya, Swapnadip De Chowdhury, Fahad Peerali Paloth, Ranadev Datta
Summary: Numerical simulations using two-phase computational fluid dynamics (CFD) and potential flow solvers were conducted on a S175 container ship hull to study bottom slamming phenomenon. Different coupling strategies, namely one and two way coupling methods, were considered. The analysis showed that the prediction of bottom slamming pressure from the one-way coupling method had a nearly steady difference compared to the two-way coupling method, forming the basis for a new empirical formula to estimate peak slamming pressure at various forward speeds with a relatively low computational cost.
APPLIED OCEAN RESEARCH
(2023)
Article
Engineering, Mechanical
Zhe Sun, Xu-peng Sui, A. Korobkin, Li Zou, Zhi Zong
Summary: In this paper, the original slamming force decomposition method is further improved by including the effect of gravity and using coefficients extracted from Computational Fluid Dynamics (CFD). The improved method provides an accurate approximation of the hydrodynamic force acting on entering bodies under various speed/acceleration combinations. The study shows that gravity significantly affects the slamming force for small entry speeds.
JOURNAL OF FLUIDS AND STRUCTURES
(2022)
Article
Engineering, Marine
Teguh Putranto, Mihkel Korgesaar, Kristjan Tabri
Summary: This paper presents the application of the equivalent single layer (ESL) approach for assessing the ultimate strength of ship hull girder using numerical finite element (FE) simulations. The ESL approach replaces the stiffened panel with a single plate, simplifying the modeling process and saving computational time. Two case studies demonstrate the applicability of the ESL approach, with good agreement between ESL predictions, 3D FEM, and IACS incremental-iterative method.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2022)
Article
Engineering, Marine
Zhongshu Ren, Mohammad Javad Javaherian, Christine Gilbert
Summary: A deeper understanding of hydrodynamic slamming can be achieved through the investigation of the wedge water entry problem using flexible structures. Experimental studies have shown that there is a significant change in the trend of pressure and strain when the relative stiffness parameter R passes through a critical value. The deformation of the structure also leads to a delay in the arrival time of peak pressure and a reduction in the magnitude of peak pressure during wedge water entry.
JOURNAL OF SHIP RESEARCH
(2022)
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.