Application of composite in offshore and marine structure

2008 ◽  
pp. 333-338
Keyword(s):  
Marine Structure

Vibration control of network-based offshore structures subject to earthquakes

2021 ◽  
pp. 014233122110259
Author(s):  
Hua-Nv Feng ◽  
Bao-Lin Zhang ◽  
Yan-Dong Zhao ◽  
Hui Ma ◽  
Hao Su ◽  
...  
Keyword(s):  
Sufficient Conditions ◽  
Offshore Structures ◽  
Delay Systems ◽  
Linear Matrix ◽  
Seismic Responses ◽  
Marine Structures ◽  
Damping Control ◽  
Marine Structure ◽  
Uncertain Model ◽  
Control Scheme

Marine structures are inevitably influenced by parametric perturbations as well as multiple external loadings. Among these loadings, earthquake is generally more destructive and unpredictable than others. It is significant to develop effective active control schemes to guarantee the safety, stability, and integrity of marine structures subject to earthquakes and parametric perturbations. In this paper, the problem of networked [Formula: see text] robust damping control is addressed to stabilize a marine structure subject to earthquakes. First, in consideration of perturbations of the structure parameters, an uncertain model of the networked marine structure under earthquakes is presented. Second, a robust networked [Formula: see text] control scheme is presented to suppress seismic responses of the structure. By using stability theory of time-delay systems, several sufficient conditions on robust stability of the networked marine structure system are obtained, and the linear matrix inequality methods are utilized to solve the gain matrix of the controller. Finally, simulation indicates that compared with the traditional robust [Formula: see text] control and the proposed networked [Formula: see text] control, the seismic responses amplitudes of the marine structure under the two controllers are almost the same, while the latter is more economic than the former.

Parameter Sensitivity in Numerical Modelling of Ice-Structure Interaction With Cohesive Element Method

2016 ◽  
Author(s):  
Dianshi Feng ◽  
Sze Dai Pang ◽  
Jin Zhang
Keyword(s):  
Element Model ◽  
Offshore Structures ◽  
Parameter Sensitivity ◽  
The Arctic ◽  
Cohesive Element ◽  
Structure Interaction ◽  
Marine Structure ◽  
Ice Loads ◽  
The Stability ◽  
Element Method

The increasing marine activities in the Arctic has resulted in a growing demand for reliable structural designs in this region. Ice loads are a major concern to the designer of a marine structure in the arctic, and are often the principal factor that governs the structural design [Palmer and Croasdale, 2013]. With the rapid advancement in computational power, numerical method is becoming a useful tool for design of offshore structures subjected to ice actions. Cohesive element method (CEM), a method which has been widely utilized to simulate fracture in various materials ranging from metals to ceramics and composites as well as bi-material systems, has been recently applied to predict ice-structure interactions. Although it shows promising future for further applications, there are also some challenging issues like high mesh dependency, large variation in cohesive properties etc., yet to be resolved. In this study, a 3D finite element model with the use of CEM was developed in LS-DYNA for simulating ice-structure interaction. The stability of the model was investigated and a parameter sensitivity analysis was carried out for a better understanding of how each material parameter affects the simulation results.

scholarly journals Antibiotic delivery potential of nano- and micro-porous marine structure-derived β-tricalcium phosphate spheres for medical applications

Nanomedicine ◽  
2014 ◽  
Vol 9 (8) ◽  
pp. 1131-1139 ◽  
Author(s):  
Joshua Chou ◽  
Stella Valenzuela ◽  
David W Green ◽  
Lawrence Kohan ◽  
Bruce Milthorpe ◽  
...  
Keyword(s):  
Tricalcium Phosphate ◽  
Medical Applications ◽  
Marine Structure ◽  
Antibiotic Delivery

Time Domain Hydroelastic Analysis of a Flexible Marine Structure Using State-Space Models

2007 ◽  
Author(s):  
Reza Taghipour ◽  
Tristan Perez ◽  
Torgeir Moan
Keyword(s):  
Mathematical Model ◽  
State Space ◽  
Time Domain ◽  
State Space Model ◽  
Realization Theory ◽  
Regular Waves ◽  
Alternative State ◽  
Marine Structure ◽  
Hydroelastic Analysis ◽  
The Mathematical Model

This article deals with time-domain hydroelastic analysis of a marine structure. The convolution terms in the mathematical model are replaced by their alternative state-space representations whose parameters are obtained by using the realization theory. The mathematical model is validated by comparison to experimental results of a very flexible barge. Two types of time-domain simulations are performed: dynamic response of the initially inert structure to incident regular waves and transient response of the structure after it is released from a displaced condition in still water. The accuracy and the efficiency of the simulations based on the state-space model representations are compared to those that integrate the convolutions.

Low Cycle Fatigue Analysis of Marine Structures

2006 ◽  
Author(s):  
Xiaozhi Wang ◽  
Joong-Kyoo Kang ◽  
Yooil Kim ◽  
Paul H. Wirsching
Keyword(s):  
Welded Joints ◽  
Low Cycle Fatigue ◽  
Prediction Method ◽  
Local Stress ◽  
Cyclic Plasticity ◽  
Cycle Fatigue ◽  
Stress Concentrations ◽  
Damage Prediction ◽  
Marine Structure ◽  
Number Of Cycles

There are situations where a marine structure is subjected to stress cycles of such large magnitude that small, but significant, parts of the structural component in question experiences cyclic plasticity. Welded joints are particularly vulnerable because of high local stress concentrations. Fatigue caused by oscillating strain in the plastic range is called “low cycle fatigue”. Cycles to failure are typically below 104. Traditional welded joint S-N curves do not describe the fatigue strength in the low cycle region (< 104 number of cycles). Typical Class Society Rules do not directly address the low cycle fatigue problem. It is therefore the objective of this paper to present a credible fatigue damage prediction method of welded joints in the low cycle fatigue regime.

scholarly journals Fundamental Study on Smart Structure Approach to Marine Structure

1998 ◽  
Vol 1998 (184) ◽  
pp. 513-522 ◽  
Author(s):  
Hideaki Murayama ◽  
Kazuro Kageyama ◽  
Isao Kimpara ◽  
Toshio Suzuki ◽  
Isamu Ohsawa ◽  
...  
Keyword(s):  
Smart Structure ◽  
Structure Approach ◽  
Fundamental Study ◽  
Marine Structure

Statistical Analysis of Second-Order Response of Marine Structures

1985 ◽  
Vol 29 (04) ◽  
pp. 270-284 ◽  
Author(s):  
Arvid Naess
Keyword(s):  
Volterra Series ◽  
Theoretical Method ◽  
Problem Formulation ◽  
Second Order ◽  
Quadratic Term ◽  
Closed Form Solutions ◽  
Marine Structure ◽  
Asymptotic Expressions ◽  
The Mean ◽  
Extreme Responses

A theoretical method is presented for estimating the response statistics of a marine structure that can be modeled as a second-order dynamic system subjected to a stationary, Gaussian sea. The method is particularly suitable for predicting extreme responses. The problem formulation expresses the response in terms of a second-order Volterra series, that is, including a linear and a quadratic term. For this response process the mean upcrossing frequency is found and asymptotic expressions are established that can be used to obtain closed-form solutions to the extreme-value problem.

Numerical and Experimental Investigation of Hydrodynamic Characteristics of Deformable Hydrofoils

2009 ◽  
Vol 53 (04) ◽  
pp. 214-226
Author(s):  
Antoine Ducoin ◽  
François Deniset ◽  
Jacques André Astolfi ◽  
Jean-François Sigrist
Keyword(s):  
Experimental Investigation ◽  
Structure Design ◽  
Hydrodynamic Characteristics ◽  
The Finite Element Method ◽  
Fluid Structure ◽  
Cavitation Inception ◽  
Marine Structure ◽  
Structure Problem ◽  
Volume Method ◽  
Processing Device

The present paper is concerned with the numerical and experimental investigation of the hydroelastic behavior of a deformable hydrofoil in a uniform flow. The study is developed within the general framework of marine structure design and sizing. An experimental setup is developed in the IRENav hydrodynamic tunnel in which a cambered rectangular hydrofoil is mounted. An image-processing device enables the visualization of the foil displacement. As for the numerical part, the structure problem is solved with the finite element method, while the fluid problem is solved with the finite volume method using two distinct numerical codes that are coupled through an iterative algorithm based on the exchange of the boundary conditions at the fluid-structure interface. Results obtained from the coupled fluid-structure computations including deformation and hydrodynamic coefficients are presented. The influence of the fluid-structure coupling is evaluated through comparisons with "noncoupled" simulations. The numerical simulations are in very good agreement with the experimental results and highlight the importance of the fluid-structure coupling consideration. Particular attention is paid to the pressure distribution modification on the hydrofoil as a result of deformations that can lead to an advance of the cavitation inception, which is of paramount importance for naval applications.

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