scholarly journals Engineering structures, the journal of earth-quake, wind and ocean engineering, published by: IPC Science and Technology Press

1979 ◽  
Vol 14 (4) ◽  
pp. 630-630
Author(s):  
K. C. Rockey
Keyword(s):  
Earth Quake ◽  
Science And Technology ◽  
Ocean Engineering ◽  
Engineering Structures

Study on Deformation Law About Six Degrees of Freedom Circular Foundation of Seabed

2012 ◽  
Author(s):  
Qiyi Zhang ◽  
Qinghua Wang ◽  
Ying Zhang ◽  
Qi Wang
Keyword(s):  
Degrees Of Freedom ◽  
Three Dimensional ◽  
Combined Loading ◽  
Ocean Engineering ◽  
Engineering Structures ◽  
Concentrated Force ◽  
Six Degrees Of Freedom ◽  
Deformation Law ◽  
Vertical Gravity ◽  
Elastic Mechanics

Some foundations of Ocean engineering structures are always in addition to withstand the vertical gravity loads, but also to horizontal loads induced by sea wave and current, which makes the foundation subjected to concentrated force, overturning loads and torque loads, the above loading state including vertical, horizontal and overturning moment loads are termed combined loading. So it is very necessary for the safety of ocean engineering structures to study the deformation law of submarine seabed due to combined loading. On the basis of the three-dimensional elastic mechanics solution of circular foundations, the deformation law of submarine clay under circular foundation with six degrees of freedom is analyzed in detail using numerical calculation methods. Based on the above numerical results, this paper gives the elastic deformation law of clay in three dimensional spaces, gives a modification to the traditional elasticity theoretical solutions, and gives clay coupled deformation mechanism under three-dimensional circular foundation with six degrees of freedom.

Relation Between Atmospheric Circulation Patterns in the North Atlantic and the Sea States in the Iberian Peninsula

2021 ◽  
Vol 143 (3) ◽  
Author(s):  
Cláudia Lucas ◽  
Mariana Bernardino ◽  
C. Guedes Soares
Keyword(s):  
Atmospheric Circulation ◽  
Climatic Variability ◽  
Wave Climate ◽  
Ocean Engineering ◽  
Engineering Structures ◽  
Spectral Parameters ◽  
Energy Devices ◽  
Atmospheric Circulation Patterns ◽  
Circulation Patterns ◽  
Wave Conditions

Abstract A statistical analysis of significant wave height (Hs) in a location offshore Portugal continental coast, Leixões, is performed. The spectral and parametric information of sea states at this point used in this analysis was obtained from a 21-year hindcast simulation using the spectral wave model simulating wave nearshore (SWAN) forced by wind fields produced by the Weather Research and Forecasting (WRF) model forced by the ERA-Interim reanalysis. The modeling of the climatic variability of directional spectra provides information of the shape of the expected directional spectra in the various sea states at these locations, i.e., how the spectral parameters and their probability of occurrence change in the regions studied. The occurrences of spectral classes are estimated, and for each class, the variability of the spectral parameters is described by means of joint distributions. The classification of the different sea states provides important information about the wave conditions present in the target areas. A relation between the sea states and the Lamb weather types (WTs) as well as a methodology for classifying atmospheric circulation patterns is presented in this study. The results of this study provide a description of the wave climate through demonstration of the interaction between sea states and weather patterns and relating different circulation patterns to different sea states. This study provides useful information on the wave conditions that can be utilized in the design of ocean engineering structures as well as in the assessment of the operability and safety of shipping and renewable energy devices.

Shakedown Analysis of Ocean Engineering Structures Subjected to Repeated Dynamic Loads

2014 ◽  
Author(s):  
Wang Jun ◽  
Xiongliang Yao ◽  
Zhang A'man
Keyword(s):  
Shell Thickness ◽  
Theoretical Method ◽  
Dynamic Loads ◽  
Strength Analysis ◽  
Ocean Engineering ◽  
Wave Load ◽  
Wave Impact ◽  
Engineering Structures ◽  
Shakedown Analysis ◽  
Important Place

Ocean engineering structures are frequently subjected to repeated dynamic loads caused by slamming of wave, impact of ice, dropped objects, collisions of store ship and grounding. Shakedown analysis is an extension of plastic limit analysis. Meanwhile, the dynamic strength analysis and shakedown analysis of offshore platform structure have an important place in ensuring the safety and reliability of ocean engineering structures under repeated dynamic loads. Therefore the shakedown analysis theory was introduced to the ultimate strength analysis of brace strut of semisubmersible drilling platform considering cyclic wave load. Based on the kinematic shakedown theorem, a theoretical method of shakedown analysis for typical ocean engineering structures under repeated dynamic loads was presented and compared with existing results to verify the reasonableness. According to the method of finite elastic-plastic theory, the strength of brace strut was analyzed through the overall model of semisubmersible drilling platform. Then based on the boundary conditions getting from the overall three-dimensional model, locally refined model of brace strut was obtained. By applying the theoretical method to shakedown analysis of brace strut under repeated dynamic loads, influence of shell thickness, stiffener thickness and stiffener spacing on shakedown limit were studied. The results show that the theoretical calculation method is consistent with the existing results. The limit load increases with the increase of shell thickness and stiffener thickness, while decreases with the increase of stiffener spacing.

A Method to Predict Stress Intensity Factor of Surface Crack at Weld Toe of Offshore Structures under Wave Loads

2014 ◽  
Vol 978 ◽  
pp. 118-122 ◽  
Author(s):  
Xiao Shun Yan ◽  
Xiao Ping Huang
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Crack Propagation ◽  
Surface Crack ◽  
Wave Loads ◽  
Ocean Engineering ◽  
Empirical Formulas ◽  
Engineering Structures ◽  
Weld Toe

The calculation of stress intensity factor (SIF) in fracture mechanics-based fatigue life prediction is mainly based on empirical formulas, the poor applicability of which limits the wide application of fatigue assessment based on crack propagation. This paper proposed a SIF calculation method for structures under wave loads. It was proved correct by comparing with the empirical formulas. Then, the method proposed was applied for the surface crack at weld toe of a connection between the column and brace of a semi-submersible platform. The predicted results showed that SIF ranges varied with wave loads, which were subjected to the effects of wave directions and frequencies. In addition, SIF ranges calculated by empirical formulas were very different from those of the proposed method. In order to accurately predict fatigue crack propagation life for ocean engineering structures, it is necessary to take the characters of wave loads into consideration. The proposed method in this paper may provide a reference.

Development and Utilization of Database on Corrosion of Ocean Engineering Materials and Structures

2010 ◽  
Vol 156-157 ◽  
pp. 1331-1334
Author(s):  
Zheng Li ◽  
Lei Jiang Yao ◽  
Xiao Yan Tong
Keyword(s):  
Corrosion Protection ◽  
Test Data ◽  
Corrosion Property ◽  
Ocean Engineering ◽  
Engineering Structures ◽  
Related Data ◽  
Protection Technology ◽  
Engineering Materials ◽  
Corrosion Mechanisms ◽  
Design And Manufacture

Corrosion of ocean engineering structures leads huge economic loses each year. Corrosion protection technology has already become a very important method for design and manufacture of ocean engineering structures. To decrease corrosive loses and guarantee the safety of engineering structures, extensive studies are invested to understand corrosion mechanisms and rules of engineering materials, and to develop technologies on corrosion control and protection. These research projects have produced and are producing a great amount of test data, reports, products, experiences, and so on. If all these data resources can be collected and organized in a unified platform, it will take great advantages for products design or manufacture on corrosion protection. A database, named Database on Corrosion of Ocean Engineering Materials and Structures (CDOSDB), was planned. For a designer or manufacturer, it should be considered in serving environment, corrosion property of material, methods on corrosion protection, and experiences on protection of real engineering structures. So, the CDOSDB is mainly include ocean environmental information, test data in real sea, simulating test data in lab, methods and products on corrosion protection, survey on corrosion status and protection of real engineering structures, corrosion knowledge and corrosion models. Because the related data and information were collecting from different research institutes and publications, in order to make full use of them, a uniform specification are arranged and standardized. A website is designed and the web addresses is http://www.dematers.com. It makes the database sharable.

Relation Between Atmospheric Circulation Patterns in the North Atlantic and the Sea States in the Iberian Peninsula

2020 ◽  
Author(s):  
C. Lucas ◽  
M. Bernardino ◽  
C. Guedes Soares
Keyword(s):  
Atmospheric Circulation ◽  
Climatic Variability ◽  
Wave Climate ◽  
Ocean Engineering ◽  
Engineering Structures ◽  
Spectral Parameters ◽  
Energy Devices ◽  
Atmospheric Circulation Patterns ◽  
Circulation Patterns ◽  
Wave Conditions

Abstract A statistical analysis of significant wave height (Hs) in eight locations offshore Portugal continental coast is performed. Specifically, locations at different water depths at Aguçadoura, Leixões, Nazaré, Peniche, Sines and Faro were chosen. The spectral and parametric information from these points used in this analysis was obtained from 21-year hindcast simulations using the spectral wave model SWAN. The modelling of the climatic variability of directional spectra provides reliable information of the most relevant parameters at these locations, i.e., how the spectral parameters and their probability of occurrence change in the regions studied. The occurrences of spectral classes are estimated, and for each class, the variability of the spectral parameters is described by means of joint distributions. The classification of the different sea states provides important information about the wave conditions present in the target areas. A relation between the sea states and the Lamb weather types (WTs), a methodology for classifying atmospheric circulation patterns, is presented in this study. The results of this study provide a description of the wave climate, through the interaction between the sea states and weather patterns, relating different circulation patterns to different sea states. This study provides useful information on the wave conditions that can be used in the design of ocean engineering structures, in the assessment of the operability and safety of shipping and renewable energy devices.

The Study on Hull Structure Strength Analysis and Opening Calculation of CJ46 Jack-Up Drilling Unit

2015 ◽  
Author(s):  
Zeng Ji ◽  
Chen Gang ◽  
Mo Jian ◽  
Wang Yuhan ◽  
Zhang Wei
Keyword(s):  
Yield Strength ◽  
Element Model ◽  
Strength Analysis ◽  
Ocean Engineering ◽  
Engineering Structures ◽  
Hull Structure ◽  
Key Issues ◽  
Drilling Unit ◽  
Main Support ◽  
Jack Up

The structural strength of jack-up units is the key issues in the design of ship and ocean engineering structures. Based on ABS MODU, the yield strength of CJ46 self-elevating drilling platform main hull structure is checked. Firstly, the environmental loads (wind, wave and flow) in three loading conditions which are required by specification are calculated by using GeniE (DNV). Then the 3D finite element model of main hull structure is established. The yield strength is checked and the results shown the large stress areas are leg well, jackcase which is connected with the leg and bulkhead which is main support structure under the cantilever sliding device, while the results meet the requirements of ABS MODU. Finally, the influence of the openings located in main longitudinal bulkheads are evaluated, meanwhile the main longitudinal bulkheads under skidding box need particular concern.

scholarly journals Hydrodynamic Performance of Submerged Plates During Focused Waves

2019 ◽  
Vol 7 (11) ◽  
pp. 389 ◽  
Author(s):  
Fang ◽  
Yang ◽  
Guo
Keyword(s):  
Potential Flow ◽  
Wave Structure ◽  
Flow Theory ◽  
Hydrodynamic Performance ◽  
Wave Loads ◽  
Ocean Engineering ◽  
Preliminary Calculation ◽  
Engineering Structures ◽  
Potential Flow Theory ◽  
Focused Wave

Submerged horizontal plates are widely employed in research of wave structure interaction as a simplification of coastal and ocean engineering structures. The hydrodynamic performance of submerged horizontal plates under focused waves has been seldom reported. Based on potential flow theory, this paper presents a general solution of the hydrodynamic pressure and wave forces exerted on submerged plates by a focused wave group. An existing experiment and two limiting cases are used to validate the accuracy of the present analytical model. With the validated model, the effect of wave properties and the configuration of the wave structure system on the hydrodynamic performance of submerged plates are investigated. It is found that the hydrodynamic performance of submerged horizontal plates varies with incident focused wave with different peak frequencies. The structural breadth significantly changes the hydrodynamic performance while the structural height has little influence. This paper shows the usefulness of potential flow theory for the preliminary calculation of wave loads on coastal and ocean engineering structures generated by focused waves.

Application of Fracture Mechanics in Ocean Engineering Structures Quality Control

2012 ◽  
Vol 472-475 ◽  
pp. 1257-1262
Author(s):  
Jian Ping Chen ◽  
Sheng Sun Hu ◽  
Jun Qi Shen ◽  
Bin Wang ◽  
De Qing Li
Keyword(s):  
Quality Control ◽  
Fracture Mechanics ◽  
Critical Assessment ◽  
Evaluation Criterion ◽  
Ocean Engineering ◽  
Engineering Structures ◽  
Developing Trend ◽  
Key Technologies ◽  
At Home

This paper introduced the application of Engineering Critical Assessment (ECA) technology based on fracture mechanics in ocean engineering structures. The application actualities and developing trend of ECA evaluation criterion in domestic and foreign ocean engineering structures were described. The content and process of ECA evaluation at home and abroad were compared, and the key technologies of ECA evaluation in practical projects were summarized.

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