scholarly journals Investigation of Structural Response Due to Impact Load on the Small Water Plane Area Twin Hull Autonomous Surface Vehicles (SWATH-ASV)

2018 ◽  
Author(s):  
Ahmad Zakki ◽  
Aris Triwiyatno ◽  
Bandi Sasmito
Keyword(s):  
Impact Load ◽  
Structural Response ◽  
Small Water ◽  
Autonomous Surface Vehicles ◽  
Plane Area

Experimental Study on a Motion of “Underwater Platform” Including Hydro-Elastic Deformation in Waves

2015 ◽  
Author(s):  
Motohiko Murai ◽  
Ken Haneda ◽  
Jun Yamanoi ◽  
Yuta Abe
Keyword(s):  
Numerical Simulations ◽  
Elastic Deformation ◽  
Large Scale ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Wind Condition ◽  
Small Motion ◽  
Small Water ◽  
Motion Characteristics ◽  
Plane Area

A new type of floater for floating offshore wind turbine (FOWT) was proposed. The floater, named an “underwater platform”, aims at high economic efficiency of energy generation of floating wind farm. The underwater platform is a large scale submerged structure which has small water plane area and can support several wind turbines. It is expected that the platform has small motion characteristics in waves because of its small water plane area, and it contributes for FOWT to generate energy safety. In this study, the feasibility and usefulness study about the platform was carried out through experiments and numerical simulations. The first experiment was conducted with partial rigid model of the platform to verify the feasibility. From the experiment, it was confirmed that the model has small motion characteristics in waves. The experimental results were compared with numerical simulations of potential theory and they were well matched. Besides, the coupling analysis with aero-hydro dynamics was also carried out and it was confirmed that the stability of the platform was enough in steady wind condition. The second experiment was conducted with elastic body model to study the elastic deformation of the platform in waves. From the experiment, it was confirmed that the deformation is small when the draft was 250mm (50m in the actual model).

Global Performance and Sloshing Analysis of a New Deep-Draft Semi-Submersible LNG FPSO

2008 ◽  
Author(s):  
Jang W. Kim ◽  
Jim O’Sullivan ◽  
Atle Steen ◽  
John Halkyard
Keyword(s):  
Operating Performance ◽  
Radius Of Gyration ◽  
Large Radius ◽  
Construction Sites ◽  
Small Water ◽  
Global Performance ◽  
Lng Liquefaction ◽  
Selection Of ◽  
Northwest Australia ◽  
Plane Area

A new concept of LNG FPSO based on a deep-draft semi-submersible hull is introduced. With the deep draft, small water plane area, low center of gravity and large radius of gyration, the new LNG FPSO offers very low motions. This low-motion LNG FPSO platform provides more options and flexibilities in the selection of LNG liquefaction units, LNG containment systems, construction sites, installation methods, mooring systems (i.e. no requirements for weather-vaning), riser system and less down time compared with a conventional FPSO hull. Global performance and sloshing analyses for the new LNG FPSO hull and the conventional FPSO hull are performed to compare their operating performance for West Africa and the Northwest Australia environments.

scholarly journals Drop Simulation of 6M Drum With Locking-Ring Closure and Liquid Contents

2006 ◽  
Author(s):  
Tsu-Te Wu
Keyword(s):  
Impact Load ◽  
Three Dimensional ◽  
Structural Response ◽  
Material Model ◽  
Element Model ◽  
Ring Closure ◽  
Foot Drop ◽  
Torque Load ◽  
Three Dimensional Finite Element ◽  
The Impact

This paper presents the dynamic simulation of the 6M drum with a locking-ring type closure subjected to a 4.9-foot drop. The drum is filled with water to 98 percent of overflow capacity. A three dimensional finite-element model consisting of metallic, liquid and rubber gasket components is used in the simulation. The water is represented by a hydrodynamic material model in which the material’s volume strength is determined by an equation of state. The explicit numerical method based on the theory of wave propagation is used to determine the combined structural response to the torque load for tightening the locking-ring closure and to the impact load due to the drop.

Mathematical model of small water-plane area twin-hull and application in marine simulator

2013 ◽  
Vol 12 (3) ◽  
pp. 286-292 ◽  
Author(s):  
Xiufeng Zhang ◽  
Zhenwang Lyu ◽  
Yong Yin ◽  
Yicheng Jin
Keyword(s):  
Mathematical Model ◽  
Small Water ◽  
Plane Area

scholarly journals Effect of Web Stiffeners on The Flexural Behavior of Composite GFRP- Concrete ‎Beam Under Impact Load

2021 ◽  
Vol 27 (3) ◽  
pp. 76-92
Author(s):  
Safaa Ibraheem Ali ◽  
Abbas A. Allawi
Keyword(s):  
Impact Load ◽  
Damping Ratio ◽  
Experimental Studies ◽  
Local Buckling ◽  
Structural Response ◽  
Point Load ◽  
Flexural Behavior ◽  
Elastic Behavior ◽  
Loading Path ◽  
Failure Behavior

In this paper, numerical and experimental studies on the elastic behavior of glass fiber reinforced ‎polymer (GFRP) with stiffeners in the GFRP section's web (to prevent local buckling) are presented. ‎The GFRP profiles‎ were connected to the concrete deck slab by shear connectors. Two full-scale simply supported ‎composite beams (with and without stiffeners) were tested under impact load (three-point load) to ‎assess its structural response. The results ‎proved that the maximum impact force, maximum ‎deflection, damping time, and ‎damping ratio of the composite beam were affected by the GFRP ‎stiffeners‎. The experimental results indicated that the damping ratio and deflection were diminished compared to hybrid beam without stiffeners by ‎‎16% and 22%, respectively, and increasing damping time‏ by 26%. Finite element models were used to study pre-failure behavior. ‎ The numerical modeling results showed good agreement with experimental data in terms of loading path and ‎final load. The damping ratio and midspan deflection values were greater than the experimental ‎values by 6% and 12%, respectively.

scholarly journals PROFITABLE HIGH-SPEED PASSENGER VESSEL FOR SHORT LINES AT SEA

2020 ◽  
Vol 8 (6) ◽  
pp. 142-149
Author(s):  
Victor A. Dubrovsky
Keyword(s):  
High Speed ◽  
Point Of View ◽  
Minimal Cost ◽  
Small Water ◽  
Alternative Option ◽  
Motion Characteristics ◽  
Passenger Vessel ◽  
Selection Of ◽  
Plane Area

The paper [1] had presented an alternative option of outrigger high-speed passenger vessel for short lines. Such ships can compete with existed ones from economy point of view if the firsts will have minimal cost of building and minimal operation price, firstly – because of minimal outlay of fuel, but for comparable service speed and capacity of passengers. Besides, usually small enough vessels are strongly affected by weather, by waves in main. It means, seaworthiness of such ships is a permanent problem if they must operate at more or less severe conditions of weather. Two newly proposed options of outrigger ships are described below: the first has small water-plane area of the main hull bow, and the second has small water-plane area of the main hull as a whole. The selection of the main dimensions are shown in main, the results are discussed from seaworthiness point of view. Both new options are recommended for further designing, including researching of motion characteristics and possible economy results.  

Reconstruction of Impact Loads within Fibre Reinforced Polymers

2007 ◽  
Vol 7-8 ◽  
pp. 209-215
Author(s):  
Ch.R. Koenig ◽  
D.H. Mueller ◽  
O. Focke ◽  
Mircea Calomfirescu
Keyword(s):  
Impact Load ◽  
Structural Response ◽  
Impact Loads ◽  
Structural Failure ◽  
Reinforced Polymers ◽  
Load Monitoring ◽  
Discrete Measurement ◽  
Structural Failures ◽  
Impact Damages ◽  
Primary Impact

Fibre reinforced polymers (FRP) offer a high potential to reduce kinetic energy. As a consequence of this, fibre reinforced polymers often have a higher risk of being exposed to impact loads. The knowledge of the mechanisms and of the material loading during and shortly after an impact load is essential for an ‘impact-load-monitoring-system’ to predict possible structural failures. Especially a prognosis of structural failures caused by – often unrecognized - barely visible impacts is an important factor. Primary impact damages often leads to a sudden structural failure. These unheralded failures seems to be one of the most important problems in product development for the aircraft industry. By measuring the structural response at several discrete measurement points an impact can be detected, reconstructed and also rated.

A Comparative Study on the Impact Damage of Membrane Type LNGC Insulation System

2009 ◽  
Author(s):  
Min Sung Chun ◽  
Yong Suk Seo ◽  
Ito Hisasi ◽  
Wha Soo Kim ◽  
Byeong Jae Noh ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Failure Mode ◽  
Impact Load ◽  
Impact Damage ◽  
Structural Response ◽  
Structural Safety ◽  
Structural Behavior ◽  
Insulation System ◽  
Membrane Type ◽  
The Impact

To verify the structural safety under impact load caused by sloshing of LNG is one of the main issues in the design of membrane type LNG cargo containment system of LNG carrier. In order to estimate structural response under sloshing impact load, many kinds of studies including experimental test and numerical simulation have been done by various research groups such as shipyards, oil companies, universities as well as classification societies. In spite of these efforts, many uncertainties still exist to predict the structural behavior of LNG insulation system under sloshing impact load. Therefore, it can be regarded as a challenge to investigate dynamic response of LNG cargo insulation system against sloshing load. In this paper, Cooperative research results obtained by SHI-HHI-PNU-Lloyd-ABS-DNV JDP focused on the impact damage or failure mode of membrane type LNG cargo insulation system are summarized. A systematic experimental research is carried out to find out failure mode of the insulation system under impact load and criteria which can be applied for the design of LNG carrier. A series of dry drop tests as well as static compressive tests are carried out. The structural behavior of the specimen under impact load is recorded using ultrahigh-speed camera and reaction force is measured using load cells which are installed under bottom of the test facility. By analyzing recorded video, deformation history of the specimen at impact moment is obtained. The numerical simulations are also carried out for the dry drop test for verification purpose, It is expected that the insights observed from the systematic experiments and numerical simulations for the structural response of the LNG cargo insulation system subjected to the impact load can be effectively used as design guide for evaluation of the integrity of structural components of LNG cargo hold system.

Material model uncertainty quantification using evidence theory

2013 ◽  
Vol 227 (10) ◽  
pp. 2165-2181 ◽  
Author(s):  
S Salehghaffari ◽  
M Rais-Rohani
Keyword(s):  
Uncertainty Quantification ◽  
Impact Load ◽  
Evidence Theory ◽  
Constitutive Models ◽  
Structural Response ◽  
Material Model ◽  
Optimization Techniques ◽  
Belief Structure ◽  
Analysis And Design ◽  
Efficient Calculation

Uncertainties in material models and their influence on structural behavior and reliability are important considerations in analysis and design of structures. In this article, a methodology based on the evidence theory is presented for uncertainty quantification of constitutive models. The proposed methodology is applied to Johnson–Cook plasticity model while considering various sources of uncertainty emanating from experimental stress–strain data as well as method of fitting the model constants and representation of the nondimensional temperature. All uncertain parameters are represented in interval form. Rules for agreement, conflict, and ignorance relationships in the data are discussed and subsequently used to construct a belief structure for each uncertain material parameter. The material model uncertainties are propagated through nonlinear crush simulation of an aluminium alloy 6061-T6 circular tube under axial impact load. Surrogate modeling and global optimization techniques are used for efficient calculation of the propagated belief structure of the tube response, whereas Yager’s aggregation rule of evidence is used for multi-model consideration. Evidence-based uncertainty in the structural response is measured and presented in terms of belief, plausibility, and plausibility-decision values.

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