28th March 2018 The Institute of Marine Engineering, Science and Technology (IMarEST)

Auxetic structures for marine safety applications(rope, sandwich panel)

Nadimul Faisal, Abbi McLeod, Findlay Booth, Lindsay Scott, Scott Duncan, Ghazi Droubi

School of Engineering, Robert Gordon University, Aberdeen, UK

Contents

1. Introduction (condition monitoring research group)

2. Background (recent examples & motivations)

3. Safety in marine structures

4. Safety practices

5. Auxetic structure design (three examples: anchor, panel)

6. Summary

© School of Engineering, Robert Gordon UniversityAuxetic structures for marine safety applications 2

Condition Monitoring Research Group (CMRG)

The research at the Condition Monitoring (CM)covers a wide range of field, including:• Condition monitoring of engines, corrosion,

vibration, thermal spraying, fracture, crack propagation

• Computational fluid dynamics approach for particle monitoring (multi-phase flow)

• Sensor based instrumented mechanical testing• Micromechanics of materials, thermal spray

coatings, thin films, bonded joints, etc. • Neutron diffraction residual strain analysis

(coatings, rocks)• Fracture mechanics (mode-I, II, mixed-mode)• Auxetic structures• Analytical/numerical modelling

Iain Steel Ghazi Droubi Sha Jihan Nadimul Faisal

Academic Staff

• Dr Nadimul Faisal [Acoustic Emission,

Micromechanics, Instrumented Mechanical

Testing, Corrosion, Neutron] [group lead]

• Dr Ghazi Droubi [Acoustic Emission, Erosion and

Corrosion Management, Multiphase Modelling ]

• Prof John Steel [Acoustic Emission, Condition

Monitoring, Vibration]

• Dr Sha Jihan [Acoustic Emission, Ultrasonic

Testing]

Acoustic Emission

Laser VibrometerUltrasonic

Eddy Current

Accelerometer

Corrosion (EIS)

Main Facilities (Condition Monitoring)

Others:

Strain gauge

Force transducer

Displacement transducer

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Background (recent examples & motivations)

• https://www.theguardian.com/us-news/2017/jun/16/us-navy-destroyer-collides-ship-japan

• http://www.bbc.co.uk/news/world-asia-40310563

• http://abcnews.go.com/US/navy-destroyers-deadly-collision-container-ship-japan/story?id=48131357

• https://www.nytimes.com/interactive/2017/06/18/world/asia/path-ship-hit-uss-fitzgerald.html

On the 17th of June 2017, a 9,000 tonne American Naval

Destroyer, the “USS Fitzgerald”, was struck in the side by a

29,000 tonnes freight carrier. The damage was severe and

resulted in several fatalities.

Recent examples (Collision)Marine Accident Investigation Branch reports; https://www.gov.uk/maib-reports

• Failure of mooring line on board LNG carrier Zarga with 1 person injured; https://www.gov.uk/maib-reports/failure-of-mooring-line-on-board-lng-carrier-zarga-with-1-person-injured

• Collision between rigid inflatable boats Osprey and Osprey II resulting in serious injuries to 1 passenger; https://www.gov.uk/maib-reports/collision-between-rigid-inflatable-boats-osprey-and-osprey-ii-resulting-in-serious-injuries-to-1-passenger

• Contact made by passenger ferry Uriah Heep with Hythe Pier; https://www.gov.uk/maib-reports/contact-made-by-passenger-ferry-uriah-heep-with-hythe-pier

• Collision between ro-ro freight ferry Petunia Seaways and historic motor launch Peggotty; https://www.gov.uk/maib-reports/collision-between-ro-ro-freight-ferry-petunia-seaways-and-historic-motor-launch-peggotty

• Collision between pure car carrier City of Rotterdam and ro-ro freight ferry Primula Seaways; https://www.gov.uk/maib-reports/collision-between-pure-car-carrier-city-of-rotterdam-and-ro-ro-freight-ferry-primula-seaways

• Collision between general cargo vessel Daroja and oil bunker barge Erin Wood; https://www.gov.uk/maib-reports/collision-between-general-cargo-vessel-daroja-and-oil-bunker-barge-erin-wood

• Collision between the stern trawler Karen and a dived Royal Navy submarine; https://www.gov.uk/maib-reports/collision-between-the-stern-trawler-karen-and-a-dived-royal-navy-submarine

• Collision between stern trawlers Good Intent and Silver Dee resulting in Silver Dee sinking; https://www.gov.uk/maib-reports/collision-between-stern-trawlers-good-intent-and-silver-dee-resulting-in-silver-dee-sinking

• Collision between container vessel Ever Smart and oil tanker Alexandra 1; https://www.gov.uk/maib-reports/collision-between-container-vessel-ever-smart-and-oil-tanker-alexandra-1 6

Recent examples (Collision, as on 31 Aug 2017)

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Mooring system failure

• The primary objective of amooring system is to maintainvessel position, protect therisers, and prevent collision withnearby infrastructure.

• Failure types: single line failure,two line failure, or at the pointof collision or riser failure, etc.

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Safety in marine structures

• As human errors and technical failures cannot be prevented easily,measures can be taken to reduce the probability of risk of severeharm if an accident does occur.

• By attaching highly energy absorbent sandwich structures to theoutside of the ship, it is thought that this will help prevent criticaldamage to a vessel and therefore prevent any future fatalities orexpensive structural damage to marine structures.

9

Incidents are categorised in the Port Operations Manual as follows: • Groundings

• Ships collision

• Ship contact

• Quay contact

• Rope parting

• Touching bottom

• Equipment failure

• Near miss

• Contact with port installation

• Miscellaneous

10Ref: Port Marine Safety Code\Fowey PMSC Sept 2017

Some practices (marine safety)

• Passive mountings between items of machinery and a flexible supportstructure such as rubber mounts and wire rope isolators.

• Passive mountings provides adequate isolation at high frequencies, thepassive solution loses its effectiveness at lower frequencies due to its ownnatural frequency.

• In the case of submarines, the advanced performance is required so far athigh frequencies in order to retain the stealth function. The use of activecontrol techniques can effectively cope with these problems.

• Hybrid mount (rubber mount and piezo-stack actuators) combined passive mounting devices with active technology represents a new alternative for naval ships.

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Auxetic structures

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• Greek terms ‘auxetikos’ and ‘auxesis’which mean “that which tends toincrease” and “increase” respectively,

• Auxetic – enhanced mechanicalproperties, negative Poisson’s ratio.

• Due to the high energy absorbingproperties they have been used forshock and sound absorbers, bodyarmour, elbow pads, and packingmaterials.

• Auxetic fibres can be used to reinforcecomposites as they resist being pulledout due to the expansion upon applyinga tensile load.

Enhanced Indentation Resistance

Conventional

Material

Auxetic

Material

Applications of materials with NPR

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Acknowledgement: Andrew Fowlie, Joe Connell, Sean Mackenzie, Ryan Noble, Jennifer McConnachie

Example 1: Helical auxetic yarn (HAYS) – Analytical & Simulation

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Figs. HAY model showing deformation (straight core with

helically wound wrap)

Ref: J. McAfee, N. H. Faisal, Parametric sensitivity analysis to maximise auxetic effect of polymeric

fibre based helical yarn, Composite Structures, 162, 2017, p. 1–12

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Input parameters for models

Example 1: Helical auxetic yarn (HAYS) – Analytical & Simulation

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Example 2: Helical auxetic yarn (HAYS) – Experimental & Analytical

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Fig. Maximum negative instantaneous Poisson’s ratio when

varying initial wrap angle.

Fig. Experimental set-up: (a) Scotch-Weld™ epoxy structural DP190 adhesive

bonding between the rubber and the nitinol, (b) cross-section of chuck with the

bolt tightened onto the wrap, (c) tensile loading experimental layout, and (d)

using ImageJ to measure extension and lateral expansion of HAY.

Acknowledgement: Andrew Fowlie, Joe Connell, Sean Mackenzie, Ryan Noble, Jennifer McConnachie

Example 2: Helical auxetic yarn (HAYS) – Experimental & Analytical

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Fig. Pictures with the corresponding

axial strains (experiment 1) shown here

in sequential order (a) to (l).

VIDEO

Example 2: Helical auxetic yarn (HAYS) – Experimental & Analytical

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Fig. Set 2/Analytical

configuration: (a) predicted

effective diameter of model

1 (core: rubber, wrap:

nitinol) against HAY axial

tensile strain, and (b)

predicted Poisson's ratio for

of model 1 (core: rubber,

wrap: nitinol) throughout

the tensile process.

Fig. Set 1/Analytical configurations: (a) predicted effective

diameter of model 1 (core: rubber, wrap: nitinol) against HAY

axial strain, (b) predicted Poisson's ratio for each HAY model

throughout the tensile process, and (c) maximum NPR as the

Poisson's ratio of the core is varied.

Example 2: Helical auxetic yarn (HAYS) –Experimental & Analytical

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Fig. Comparison of the experiments 1, 2 and 3 (three tensile

testing on HAYs), as per Set 2 analytical configuration with

rubber as core and nitinol as wrap materials: (a) load-extension

profile, and (b) calculated Poisson's ratio plotted against axial

strain throughout the tensile process.

Fig. 8. Comparison between the analytical prediction (as per Set 2 analytical

configuration with rubber as core and nitinol as wrap materials) and the average

from the three tensile experiments of HAYs.

Example 2: Helical auxetic yarn (HAYS) –Experimental & Analytical

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(a)

Fig. (a) All three tensile tested HAYs, (b) frictional forces after the

epoxy resin failed, and (c) failure of epoxy resin from experiment 3 –

(A) area subjected to stress from the bolt in the chuck (B) remaining

part of the nitinol wire after failure.

HAY with graphene coated wrap

Potential materials (Core, Wrap) for HAY design

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Auxetic Panels

Design and Analysis of Sandwich Auxetic StructureFor Marine Safety Applications

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Aim & Objectives

• Modify an auxetic cell to reduce the stress concentrations within the structure.

• To fill the modified auxetic structure to achieve a greater energy absorbance to enhance safety applications.

Aims and Objectives

Introduction

• What is an Auxetic?• Negative Poisson’s Ratio (NPR)

• Expands when tensile force applied

• Contracts when compressed

Enhanced Indentation Resistance

Conventional

Material

Auxetic

Material

• Marine Accidental

Investigations (MAI)

Use of Auxetics

• Footwear – sole can expand, increasing flexibility

• Biomedical – smart bandages, dilators for opening arteries

• Impact resistance – bulletproof vests, blast curtains, armoured vehicles, IED containment

• Shock and vibration absorption properties

Use of Auxetics

• The dimensions chosen for the modified strut design were:

• θ = 60°

• t = 1mm

• l = 3.75mm

• h = 9.80mm

• S = 4.80mm

Design Parameters

Design Methodology

• Cell Optimisation:

• Cell modifications

• Analytical study

�� �

ℎ�

� �� ��

���

Calculations

• m=5,500 tonne

• V=2m/s

Force Equation(full size)

! �"

#

! �11 ∗ 10'

5

)* � +. + -.

Force Equation(scale model size)

!1

!2

�31

32

)4 � 55 6.

Energy Equation (full size)

" �1

2:;

< � 55 -=

29Basic model with steel base-plates

Finite Element Analysis (Elastic, Perfect Bonding)

Initial Simulations (MK0)

Yield Strength of Steel

Yield Strength of PP

MK1

MK2

MK3 Filling of cell rows (probes)

Basic Model – Path Analysis (Path 1)

Basic Model Elevation with Stress Paths and Row Numbers

Basic Model – Path Analysis (Path 1)

Basic Model – Path Analysis (Path 4)Basic Model - Path Analysis (Path 4)

Basic Model – Path Analysis (Path 3)Basic Model – Path Analysis (Path 3)

Filling Patterns (No Fill)Filling Patterns (No Fill)

Filling Patterns (Silly Putty Fill)Filling Patterns (Silly Putty)

Filling Patterns (PVC Fill w/ Silly Putty Row 5)Filling Patterns (PVC Rows 1-4, Silly Putty Row 5)

Filling Patterns (PVC Fill)Filling Patterns (PVC Fill)

Enhanced Model – Path Analysis (Path 1)Enhanced Model – Path Analysis (Path 4)Enhanced Model – Path Analysis (Path 3)

Energy Absorption

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Conclusion

• Filling and filleting the auxetic structure: reduced stress concentrations and decreased energy absorption.

• Decreased stress concentration increased the structures penetration resistance.

Summary

• Possible applications for HAYs made of light-weight materials such as PEEK orPTFE could replace conventional structures have been identified.

• A maximum NPR of -12.04 was achieved by lowering the wrap starting angle. Thefindings show that a starting wrap angle of 7° will produce the highest NPR. Thisshould be the design angle for optimised performance of the yarn.

• The use of a nitinol wrap is expected to increase the maximum NPR of a HAYcompared with conventional materials such as stainless steel or carbon fibre.Materials with low coefficients of friction such as PTFE or acetal would enhancethe auxetic behaviour if used as for the core material.

• While filling the model with material reduced the stress concentration, it led to areduction in the energy absorbance. The energy absorbed by an impact is of highimportance to the structural integrity of the vessel.

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Robert Gordon University

Any Questions, Comments or

Suggestions!!!

Nadimul Haque FaisalPhD, FHEA, CEng MIMechE, MIMMM

School of Engineering, Robert Gordon University

N.H.Faisal@rgu.ac.uk

+44-1224-262438

Thank you