DESIGN AND ANALYSIS OF

SELF-HEALING SANDWICH COMPOSITES

SupervisorDr R. Asokan, PhDProfessorSchool Of Aeronautical SciencesHindustan University

Prepared By:-Arjun Balachandran

(1100108015)Athira Chandra Babu

(1100108019)Dhinesh Karthikeyan

(1100108036)Pranavu Raveendran

(1100108106)

OUTLINEINTRODUCTION/OBJECTIVE

APPROACHES TO SELF-HEALING

MATERIAL SELECTION

FABRICATION

EXPERIMENTAL RESULTS

CONCLUSIONS & FUTURE DIRECTIONS

INTRODUCTION•Use of composites are rapidly increasing

in all the industries•Beside the advantages they are

intolerable to damages •Matrix de-lamination, fibre fracture, fibre

de-bonding and fiber pull out can occur during impact load

OBJECTIVE•To analyze two different sandwich

composite materials that are adhesively joined by epoxy resin and self healing resins to know the flexural rigidity, resistance to impact and to perform water observation on the specimens

SELF HEALING MATERIALS•Self healing composites are a class of

smart composites that is structurally incorporated with the ability to repair the damage caused by mechanical usage over time

•Inspired from biological healing systems

SELF HEALING CLASSIFICATION

• Capsule Based• Vascular Based• Intrinsic

CAPSULE BASED HEALING•The healing agent is stored in discrete

capsules•Damage triggers rupture and capsule

contents are released•Thus Self Healing takes place due to the

triggering of the capsules

VASCULAR BASED HEALING•Similar to that of capsule based healing

method•Vascular Method can either be 2-

dimensional or 3 – dimensional•Healing is based on capillarity

INTRINSIC SELF HEALING•Less complex design for self healing

mechanism •Matrix is self healing inherently and thus

no release of self healing agents is required

•Avoids the cons of integration and healing-agent compatibility that usually arise in capsule based and vascular based healing systems

IONOMERIC SELF HEALING (INTRINSIC)•Copolymers - the materials has ionic

segments that can form which acts as crosslink

•Simulated by external stimuli•Multiple Local Healing •Formation of above mentioned clusters

are reversible

VASCULAR BASED HEALING – 2D

VASCULAR BASED HEALING – 3D

CAPSULE BASED HEALING – 2D

INTRINSIC SELF HEALING

FACING & CORE SELECTION• FACING

E - Glass Fibre

• CORE

PVC Foam

Self Healing Resin + Hardener (UR5083)Resin LY 556 + Hardener HY 951

E-GLASS• Electrical grade and low alkali

glass

• For its relatively low cost

it is a remarkable material

•  Light weight with an inherent

strength to provide a weather

resistant finish

E GLASS PROPERTIES

PVC FOAM• Closed cell foam, based on

divinyl polymer, modified

with the throughout aramids

link

• Core material for sandwich

structure

• Foam is perforated with

2mm holes(based on foam

thickness and density) 300 x 300 x 10 mm PVC FOAM

PVC FOAM PROPERTIES

EPOXY RESIN• Resin (Used) – LY 556

Hardener(Used) – HY 951• Ratio :- 100:12• Cures at room temperature

• Excellent adhesive strength

• Good Mechanical and Electrical Properties

EPOXY RESIN (CURED) PROPERTIES

SELF HEALING RESIN (UR5083)• Polyurethane Resin

• Ratio of Resin to Hardener 2:1

• Excellent impact resistance

• Good adhesion to a variety of substrates

• Excellent electrical properties

• Low water absorption

• Fire resistance

SELF HEALING RESIN (CURED) PROPERTIES

FABRICATION – A CASE STUDY• Fabrication is done using

Vacuum Infusion technique

• Material Failed due to the wrong ratio of epoxy resin and hardener

FABRICATION – HAND LAY UP• Preparing the mould

• Material Preparation

• Pre measured resin and hardener is mixed thoroughly

• Rollers or brushes are used to apply

• Left for curing

FABRICATED LAMINATES(300x300x15mm)

• Epoxy Adhesive Laminate • Self Healing Adhesive Laminate

WATER JET CUTTING• Water jet cutting was used to

cut the specimens for the tests

• Flexural Specimen Size 200 x 35 x 15 mm

• Water Observation Specimen Size 25 x 25 mm

• Impact Specimen Size 60 x 60 mm

FLEXURAL TEST• Behavior of materials

subjected to simple beam loading.

• 3 point bend test

• Load Displacement Curves are plotted and the comparison for both epoxy and self healing adhesive composites are shown

FLEXURAL TEST SPECIMENS SELF

HEALING

EPOXY

Flexural Test Specimen Size 200 x 35 x 15 mm

LOAD DISPLACEMENT CURVES FOR EPOXY ADHESIVE 1

LOAD DISPLACEMENT CURVES FOR EPOXY ADHESIVE 2

LOAD DISPLACEMENT CURVES FOR EPOXY ADHESIVE 3

LOAD DISPLACEMENT CURVES FOR SELF HEALING ADHESIVE 1

LOAD DISPLACEMENT CURVES FOR SELF HEALING ADHESIVE 2

LOAD DISPLACEMENT CURVES FOR SELF HEALING ADHESIVE 3

SPECIMENS AFTER FLEXURAL TESTEPOXY SPECIMENS

SPECIMENS AFTER FLEXURAL TESTSELF HEALING SPECIMENS

COMPARISON GRAPH

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 180.0

0.2

0.4

0.6

0.8

Load

(kN

)

Displacement (mm)

LOAD DISPLACEMENT CURVE FOR EPOXY ADHESIVE 1 LOAD DISPLACEMENT CURVE FOR EPOXY ADHESIVE 2 LOAD DISPLACEMENT CURVE FOR EPOXY ADHESIVE 3 LOAD DISPLACEMENT CURVE FOR SELF HEALING 1 LOAD DISPLACEMENT CURVE FOR SELF HEALING 2 LOAD DISPLACEMENT CURVE FOR SELF HEALING 3

WATER OBSERVATION• Test Specimen Size-

25 x 25 mm• Initial Weight is taken• Specimen immersed

in water for 24 hours in room temperature

• Variation in weight is observed after cleaning.

WATER OBSERVATION - DATASample Id Initial

WeightFinal Weight

Increasing Weight

Percentage of water observation

Epoxy-1 2.490 g 2.510 0.20 8.032

Epoxy-2 2.510 g 2.540 0.30 11.952

Epoxy-3 3.390 g 3.410 0.20 5.899

Self Healing-1 4.100 g 4.120 0.20 4.878

Self Healing-2 3.820 g 3.830 0.10 2.617

Self Healing-3 3.640 g 3.650 0.10 2.747

IMPACT TEST•High Velocity impact testing were

performed on the specimen•The impact tests were performed in the

following conditions Pressure = 344 737.865 PaVelocity = 37.5m/s

•Two kinds of bullets were used :- Sharp/Blunt

IMPACT TEST SPECIMEN

Self Healing Adhesive Specimens Epoxy Adhesive Specimens

Specimen Size 60 mm x 60 mm

EXPERIMENTAL SETUP

Material mounted to the specimen holder of the impact tester .

Types of Bullets used - Sharp/ Blunt

AFTER IMPACT ( BLUNT )

AFTER IMPACT (SHARP)

FINDINGS – IMPACT TEST•It is found that impact resistivity for self

healing adhesive composite is greater than that for the epoxy adhesive composites

CONCLUSIONS•Flexural test was performed, and was found

that the load carrying capacity for epoxy adhesive composites were better than that of self healing adhesive composites.

•Water resistivity of self healing adhesive specimens were found to be better compared to epoxy adhesive composites.

•Impact resistivity of self healing adhesive composites are excellent in comparison to epoxy adhesive composites.

APPLICATIONS (SCOPE)•Fairings•Control surfaces•Interior components•Aircraft panels

REFERENCES• Self-Healing Polymers and Composites B.J. Blaiszik, S.L.B. Kramer, S.C.

Olugebefola, J.S. Moore, N.R. Sottos, and S.R. White ,2010

• Self-Healing CFRP for aerospace applications, Dr Ian P Bond, Mr Gareth J

Williams & Dr Richard S Trask,2007

• Puncture Self-healing Polymers for Aerospace Applications K. Gordon, R.

Penner, P. Bogert, W.T. Yost and E. Siochi,2003

• Self-healing: a new paradigm in materials design, MR Kessler,2006 

• Low Velocity and High Velocity Impact Test on Composite Materials – A

review S.N.A. Safri,M.T.H. Sultan, N. Yidris, and F. Mustapha,2014

• Low Velocity Impact Properties of Foam Sandwich Composites: A

Brief Review, Ramadan Mohmmed, Azzam Ahmed, Mohamed

Ahmed Elgalib, Hashim Ali ,2014

• Impact Behaviour of Sandwich GFRP-Foam-GFRP Composites V.

K. Srivastava,2012

• Experiments on Epoxy, Polyurethane and ADP Adhesives Julia de

Castro San Román,2005

• Moisture Absorption Properties of Unidirectional Glass/Polymer

Composites Used in Composite (Non-Ceramic) Insulators L.

Kumosa, B. Benedikt, D. Armentrout and M. Kumosa,2004

• Self-sealing of mechanical damage in a fully cured structural

composite Jericho L. Moll , Henghua Jin, Chris L. Mangun , Scott

R. White , Nancy R. Sottos, 2013