A Rubber Bag for Liquid Cargo to Improve Ship Collision Safety

Collisions and grounding accidents of ships, but also the failure of the hull-integrity, can lead to oil leakage. Examples are the Rena in 2011, the Hebei Spirit in 2007 and the much known accident of the Prestige in 2002. Consequently research regarding the enhancement of the structural design to increase the safety-level of ships in case of accidents is important. In this paper the use of a rubber bag as a second barrier is presented as an alternative concept to prevent oil leakage in case of accidents. The influence of the rubber bag is investigated using the example of a ship collision. A simplified tanker side structure as well as a box shaped rubber bag are analyzed with the finite element method. The material model for the rubber bag is calibrated with tensile tests to obtain the required material parameters. The reaction forces and the associated penetration depth are analyzed. The comparison is done between the structure with and without the rubber bag. For the latter, the general behavior is compared with large-scale experimental results. Furthermore an additional increase of the survivability of the ship due to the rubber bag without changing the common structural design is discussed.

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A Rubber Bag for Liquid Cargo to Improve Ship Collision Resistance

Journal of Offshore Mechanics and Arctic Engineering ◽

10.1115/1.4037486 ◽

2017 ◽

Vol 140 (1) ◽

Author(s):

Jan M. Kubiczek ◽

Sören Ehlers ◽

Lars Molter

Keyword(s):

Structural Design ◽

Large Scale ◽

Material Model ◽

Tensile Tests ◽

Fe Method ◽

Additional Increase ◽

Safety Level ◽

Collision Resistance ◽

Oil Leakage ◽

Ship Collision

Collisions and grounding accidents of ships, but also the failure of the hull-integrity, can lead to oil leakage. Examples are the Rena in 2011, the Hebei Spirit in 2007, and the much known accident of the Prestige in 2002. Consequently, research regarding the enhancement of the structural design to increase the safety-level of ships in case of accidents is important. In this paper, the use of a rubber bag as a second barrier is presented as an alternative concept to prevent oil leakage in case of accidents. The influence of the rubber bag is investigated using the exemplary simulation of a ship collision. A simplified tanker side structure as well as a box-shaped rubber bag is analyzed with the finite element (FE) method. The material model for the rubber bag is calibrated with tensile tests to obtain the required material parameters. The reaction forces and the associated penetration depth are analyzed. The comparison is done between the structure with and without the rubber bag. For the latter, the general behavior of an empty tank in a ship side structure is compared with the large-scale experimental results. Furthermore, an additional increase of the collision resistance of the ship due to the rubber bag without changing the common structural design is discussed.

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The Effect of Solution Heat Treatment and Natural Ageing on the Yield Characteristics of a 2024-O Aluminium Alloy

10.1115/imece2000-1869 ◽

2000 ◽

Author(s):

M. T. J. Ashbridge ◽

A. G. Leacock ◽

K. R. Gilmour ◽

M. F. O’Donnell ◽

D. McDonnell

Keyword(s):

Heat Treatment ◽

Finite Element ◽

Solution Heat Treatment ◽

Large Scale ◽

Biaxial Tension ◽

Yield Criterion ◽

Deformation Behaviour ◽

Material Model ◽

Tensile Tests ◽

Age Hardening

Abstract Recent advances in computational technology have allowed engineers to conduct previously impractical analyses, particularly with the development of the Finite Element Method (FEM). In turn, this has led the sheet metal forming industry into an economy drive, with an increasing necessity for ‘first time’ forming operations and reduced scrap rates. The successful prediction of large-scale plastic deformation in a sheet component relies on the accuracy of the material model used, especially when anisotropic materials are considered. Some stretch formed or deep drawn forms are geometrically complex and may require several draws with inter-stage anneals and/or solution heat treatments to achieve full form, and the varying material properties create significant difficulties in the modelling of these forming processes. Current orthotropic yield criteria do not allow for any sense of time dependency and although the atomic effects of solution heat treatment and precipitation hardening are well understood, the macroscopic effects of deformation behaviour are not. A test program was developed to investigate the effects of an increasing age hardening time on an aerospace Alclad 2024-O material after a solution heat treatment. With access to industrial heat treatment equipment, extensive tensile tests were conducted at varying age hardening times and a test rig was manufactured to obtain balanced biaxial tension data. Through the subsequent analysis, a method of predicting the data needed to generate a materials model suitable for FEA was developed, based on a modified version of Hill’s 1990 non-quadratic yield criterion. This was used to generate yield loci for the various age hardening times and compared with the loci generated with the predicted loci. Evaluation of the accuracy of the new criterion, and hence the predictive method, was achieved through its implementation in a finite element code used to model a punch-stretch test. Modelled surface strains were then compared with those measured strains determined during an empirical validation test programme. With the knowledge that the analysis came from data predicted from a minimum of empirical tests, the predicted results were found to be in good agreement with the experimental values.

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Experimental Research on Bond Behaviour of Fabric Reinforced Cementitious Matrix Composites for Retrofitting Masonry Walls

International Journal of Concrete Structures and Materials ◽

10.1186/s40069-021-00460-1 ◽

2021 ◽

Vol 15 (1) ◽

Author(s):

Fayu Wang ◽

Nicholas Kyriakides ◽

Christis Chrysostomou ◽

Eleftherios Eleftheriou ◽

Renos Votsis ◽

...

Keyword(s):

Large Scale ◽

Tensile Tests ◽

Seismic Resistance ◽

Matrix Composites ◽

Bond Behaviour ◽

Cementitious Matrix ◽

The Matrix ◽

Rc Frame Buildings ◽

Direct Tensile ◽

Fabric Reinforced Cementitious Matrix

AbstractFabric reinforced cementitious matrix (FRCM) composites, also known as textile reinforced mortars (TRM), an inorganic matrix constituting fibre fabrics and cement-based mortar, are becoming a widely used composite material in Europe for upgrading the seismic resistance of existing reinforced concrete (RC) frame buildings. One way of providing seismic resistance upgrading is through the application of the proposed FRCM system on existing masonry infill walls to increase their stiffness and integrity. To examine the effectiveness of this application, the bond characteristics achieved between (a) the matrix and the masonry substrate and (b) the fabric and the matrix need to be determined. A series of experiments including 23 material performance tests, 15 direct tensile tests of dry fabric and composites, and 30 shear bond tests between the matrix and brick masonry, were carried out to investigate the fabric-to-matrix and matrix-to-substrate bond behaviour. In addition, different arrangements of extruded polystyrene (XPS) plates were applied to the FRCM to test the shear bond capacity of this insulation system when used on a large-scale wall.

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Actual Problems of the Safety and Reliability of the NPP Structures in Slovakia

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.738.261 ◽

2017 ◽

Vol 738 ◽

pp. 261-272 ◽

Cited By ~ 1

Author(s):

Juraj Kralik

Keyword(s):

Risk Assessment ◽

Numerical Methods ◽

Probabilistic Analysis ◽

Material Model ◽

Safety Level ◽

Concrete Cracking ◽

The World ◽

Safety And Reliability ◽

Long Time ◽

Calculated Model

The last accidents of the NPP in Chernobyl and Fukushima give us the new inspiration to verify the safety level of the NPP structures. This paper presents the new requirements to test of the safety and reliability of the NPP structures due to the last accidents in the world. The risk assessment to verify of the safety and reliability of the NPP structures based on probabilistic and nonlinear analysis is presented. The uncertainties of the loads level (long-time temperature and dead loads), the material model (concrete cracking and crushing, behaviour of the reinforcement and liner), degradation effects and other influences following from the inaccuracy of the calculated model and numerical methods were taken into account in the LHS method. The results of the deterministic and probabilistic analysis of the NPP structures are presented.

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A Material Model for the Orthotropic and Viscous Behavior of Separators in Lithium-Ion Batteries under High Mechanical Loads

Energies ◽

10.3390/en14154585 ◽

2021 ◽

Vol 14 (15) ◽

pp. 4585

Author(s):

Marian Bulla ◽

Stefan Kolling ◽

Elham Sahraei

Keyword(s):

Mechanical Behavior ◽

Lithium Ion ◽

Material Model ◽

Tensile Tests ◽

Element Analysis ◽

Rate Dependent ◽

Novel Material ◽

Li Ion ◽

Role Based ◽

Drive Systems

The present study is focused on the development of a material model where the orthotropic-visco-elastic and orthotropic-visco-plastic mechanical behavior of a polymeric material is considered. The increasing need to reduce the climate-damaging exhaust gases in the automotive industry leads to an increasing usage of electric powered drive systems using Lithium-ion (Li-ion) batteries. For the safety and crashworthiness investigations, a deeper understanding of the mechanical behavior under high and dynamic loads is needed. In order to prevent internal short circuits and thermal runaways within a Li-ion battery, the separator plays a crucial role. Based on results of material tests, a novel material model for finite element analysis (FEA) is developed using the explicit solver Altair Radioss. Based on this model, the visco-elastic-orthotropic, as well as the visco-plastic-orthotropic, behavior until failure can be modeled. Finally, a FE simulation model of the separator material is performed, using the results of different tensile tests conducted at three different velocities, 0.1 mm·s−1, 1.0 mm·s−1 and 10.0 mm·s−1 and different orientations of the specimen. The purpose is to predict the anisotropic, rate-dependent stiffness behavior of separator materials in order to improve FE simulations of the mechanical behavior of batteries and therefore reduce the development time of electrically powered vehicles and consumer goods. The present novel material model in combination with a well-suited failure criterion, which considers the different states of stress and anisotropic-visco-dependent failure limits, can be applied for crashworthiness FE analysis. The model succeeded in predicting anisotropic, visco-elastic orthotropic and visco-plastic orthotropic stiffness behavior up to failure.

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Establishment of an ANSYS-Based Constitutive Modeling for Age Forming of Aluminum Alloy

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.217-219.1497 ◽

2012 ◽

Vol 217-219 ◽

pp. 1497-1500 ◽

Cited By ~ 2

Author(s):

Xiao Jun Zuo ◽

Jun Chu Li ◽

Da Hai Liu ◽

Long Fei Zeng

Keyword(s):

Aluminum Alloy ◽

Constitutive Equation ◽

Material Model ◽

Tensile Tests ◽

Material Constants ◽

Tensile Process ◽

Simulation Based ◽

Optimal Material ◽

Two Stages ◽

Good Agreement

Constructing accurate constitutive equation from the optimal material constants is the basis for finite element numerical simulation. To accurately describe the creep ageing behavior of 2A12 aluminum alloy, the present work is tentatively to construct an elastic-plastic constitutive model for simulation based on the ANSYS environment. A time hardening model including two stages of primary and steady-state is physically derived firstly, and then determined by electronic creep tensile tests. The material constants within the creep constitutive equations are obtained. Furthermore, to verify the feasibility of the material model, the ANSYS based numerical scheme is established to simulate the creep tensile process by using the proposed material model. Results show that the creep constitutive equation can better describe the deformation characteristics of materials, and the numerical simulations and experimental test points are in good agreement.

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Kinematic-, Static- and Workspace Analysis of a 6-P-U-S Parallel Manipulator

Volume 2: 34th Annual Mechanisms and Robotics Conference, Parts A and B ◽

10.1115/detc2010-28978 ◽

2010 ◽

Cited By ~ 7

Author(s):

Madusudanan Sathia Narayanan ◽

Sourish Chakravarty ◽

Hrishi Shah ◽

Venkat N. Krovi

Keyword(s):

Structural Design ◽

Parallel Manipulators ◽

Type I ◽

Kinematic Modeling ◽

Workspace Analysis ◽

Reaction Forces ◽

Specific Configuration ◽

Parallel Kinematic ◽

Stewart Gough Platform

This paper examines the symbolic kinematic modeling of a general 6-P-U-S (prismatic-universal-spherical) parallel kinematic manipulator (PKM). The base location of actuators has been previously shown to lead to: (i) reduction of the (motor) weight carried by the legs; (ii) elimination of the actuation transmission requirement (through intermediary joints as in the case of the Stewart-Gough platform); and (iii) most-importantly absorption of reaction-forces by the ground. We focus on using the symbolic equations to derive the conditions for type I and II singularities of this class of parallel manipulators. Based on these conditions, this system of equations is specialized to a specific configuration of the platform that has superior structural design and comparatively minimal singularities within its workspace. A series of studies were conducted to investigate the quality of workspace as well as estimate the actuation requirements for a unit payload carried over their workspace using the symbolic Jacobian model for this specialized configuration.

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