final indian journal paper 123

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Delamination of Glass Fiber Reinforced Epoxy Plastic (GFRP)

Composite Laminates of Different Orientation

1Mayuresh Bhosale,

2Rajvardhan Mane,

3,*Lokavarapu Bhaskara Rao,

1,2,3 School of Mechanical and Building Sciences, VIT Chennai, Vandalur-Kelambakkam Road,

Chennai-600127, Tamil Nadu, 1E-mail:[email protected] ,

2E-mail: [email protected] ,

3E-mail:[email protected] (

*Address for correspondence)

Abstract

Objectives: Our main objective is to study comparison of delamination factor of [0/90/0] as shown in Figure.4, [0/60/0] as

shown in Figure.5 and [0/45/0] as shown in Figure.6 oriented GFRP composite laminates. Finding includes-Variation of

delamination factor with respect to process parameters,Variation of delamination factor with respect to drilling

geometry,Variation of delamination factor with respect to fiber orientation.

Methods:

To have functional outputs from composite, machining is very important. Out of various machining operations drilling is

one of the most important operations.

Findings: This paper correlate delamination of [0/90/0], [0/60/0] and [0/45/0] GFRP composite with drilling process

parameters viz cutting speed and feed rate respectively.

Improvements/Applications: This paper gives a clear view of different behaviours of GFRP plates with different

orientations.

Keywords : GFRP, Delamination, Machining, Process Parameters

Introduction:

Composites are proved to be the effective constructive materials for present day industry due to their excellent properties.

The major advantages in terms of mechanical properties such as high stiffness-to-weight and strength-to-weight ratios of

composite materials led them to replace conventional materials like metals in broad range of applications such as aircraft,

sea vehicles, automobile, aerospace and defence. Producing error free précised holes is desired to ensure high joint strength

during assembling of materials by riveting or bolting. Damages like fiber push out as shown in Figure 1. fiber peel up as

shown in Figure 2 and delamination as shown in Figure 3. are induced by drilling operation which severely affect fatigue

strength so reduce performance of composite for long term needs. Out of above mentioned damages delamination induced

due to drilling is main area of concern in machining. In aircraft industries 60-65% parts of composite laminates are rejected

due to delamination induced by drilling. The thrust force is primary reason of delamination. The composites consists of

two primary phases: matrix and reinforcement Matrix- Matrix is important and first phase in manufacturing of composite.

It enhances properties of material.

Reinforcement: It is stronger, stiffer and harder than matrix. It modifies thermal and wear resistance and also thermal

conductivity. Extrusion, rolling, forging and drilling are done in this phase. Single filament fiber such as carbon fiber, glass

fiber and silicon fiber are used in continuous reinforcement. Physical identification is combination of both phases. Due to

increase in demand from industries for better materials in terms of mechanical properties as compared to metals but they

should be light in weight. For this reason composite materials are developed which are light in weight but with enhanced

mechanical properties. But at the same time it was also noticed that by using traditional machining processes machining

become more difficult. Those processes can affect composite materials and induces problems like fiber pullout,

mailto:[email protected]

mailto:[email protected]

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delamination, matrix burning, and fiber push out. To1 analysis this Jaimon Quadros have done drilling on GFRP material

of [0/90/0] orientation. They have drilled holes GFRP plate of different drill bits. By using image processing technique

they have got delamination. Then results are correlated with cutting force and feed at the time of process. All2 have

analyzed drilling of GFRP material by using axial drilling drill as well as helical milling machine for both wok piece

quality and economical view. During machining of any materials it is preferred to use optimized speed and feed. Sharwan3

kumar sahu has drilled GFRP material. He has used model which is combination of taguchi and grey theory for optimize

spindle speed, drill diameter and feed. Grey theory converts output responses into single responses which is useful for

study. Conducted5 experiments on Delamination in drilling GFR-thermoset composites in order to study how delamination,

thrust force and torque are influence by drill and material. He made simple technique to measure delamination. They have

plotted results for (1) delamination vs feed (2) torque vs feed (3) thrust force vs feed. Paper10

is ended with conclusions that

delamination size increases with increase in feed rate so as increase in thrust force. To study machining characteristics of

fibre reinforced polymer composites for drilling operation.

Advantages of GFRP Composites

1. The weight of Glass fiber reinforced composite is lesser than the conventional materials.

2. Corrosion resistance of GFRP is high.

3. The design of manufacturing improves Stiffness, Strength and modulus.

4. As per requirement any shape and size can be manufactured by GFRP.

5. Better fatigue resistance is achieved due to excellent damping properties.

6. Fabrication of GFRP is easy.

Problem definition-

Damages like fiber pull out, fiber pill out and delamination are induced by drilling operation which severely affect fatigue

strength so reduce performance of composite for long term needs Currently, delamination and fiber pull-out requires

manual post-machining, which is costly and time consuming in series production Input will be GFRP composite plate,

cutting speed and feed rate. Finally we will get delamination factor.

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Methodology-

GFRP plates are manufactured as per decided orientations. Then by using VMC machine holes of different diameters but at

different speed and feeds are drilled. Then holes are analyzed for delamination.

Specimen preparation-

Hand Lay-up Technique for Manufacture GFRP composite-

The method that is used in the present work for manufacturing the laminated composite plates is hand layup as shown in

Figure 4 which is the oldest method that was used to get the composite materials. Also the material properties are shown in

the table 1 below.

Reinforcement- Glass Fiber

Matrix- Epoxy Resin VBR- 8912 with hardener VBR 1209, VBR 1204

Dimension of plate- 100*50*4 (mm)

Experimental Procedure –

Machine Set up-

CNC Vertical Drilling Machine as shown in Figure.7 is used for drilling of GFRP plates of (0/90/0) orientations as shown

in Figure.8, (0/45/0) orientation as shown in Figure.6 and (0/60/0) orientation as shown in Figure.5. Probe is used to set co-

ordinates as [0/0/0] as reference values as shown in Figure.9. Hydraulic clamping system in used to hold GFRP plates as

shown n Figure.10. To ease drilling of GFRP plates they are punched for low feed and speed as shown in Figure.11. GFRP

plates are drilled for 6mm and 8mm diameter by HSS tools as shown in Figure.12. After drilling process is over final

drilled plate is obtained as shown in Figure.13.

Drilling Analysis

After drilling process is over drilled holes as shown in Figure.14 are analyzed by Photo views as shown in Figure.15 and

Figure.16. This process continues for all 18 holes.

Formula For Delamination Factor-

Fd = Dmax/d (1)

Fd= Delamination Factor

Dmax= Maximum Diameter of composite hole after drill at damage place

d = actual diameter of hole that are equal to drill bit

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Results and Discussion

Objective of this paper is to study delamination factor induced due to drilling. Once analysis is over of all 18 holes.

Maximum damaged area due to drilling is measured by using venire caliper. By measurement following results were drawn

from table 2. As per the output from the analysis table is formed. Figure.17 gives feed vs delamination behavior of (0/45/0)

GFRP plate. Figure.18 gives feed vs delamination behavior of (0/60/0) GFRP plate Figure.19 gives feed vs delamination

behavior of (0/90/0) GFRP plate. Delamination factor of GFRP plate depends upon the diameter of drill used and fiber

orientations. Strength of GFRP plates depends upon orientation of fiber due to which delamination also varies. Feed also

plays crucial role in delamination than speed. From graph it is seen that (0/90/0) and (0/60/0) give same behavior as per

standard results but (0/45/0) gives different behavior due to its orientation.

Conclusions

An overview of mechanical drilling on composite laminate is presented. Drilling of composite laminates differs

significantly in many aspects from drilling of conventional metal and their alloys. Delamination is serious damage during

drilling of composite laminates. We use here HSS drill. The hole quality can be improved by using special drill bits,

support plate, pre drilled pilot hole and high speed drilling. Some conclusions can be drawn from the figure 17 18 19.

It is conclude that a higher drill feed rate reduced the delamination zone and cutting speed having very low influence on

delamination zone. In (0/90/0) and (0/60/0) oriented GFRP plate, as feed increase delamination decreases so, we can use

this two orientations for application. In (0/45/0) oriented GFRP plate, as feed increases delamination increases and then

decreases because of which it is very difficult to decide feed rate to have minimum delamination. So, this orientation

requires more precise analysis to decide feed rate.

References-

1. Jaimon D. Quadros,Vaishak N.L., Suhas, Manoj Kumar A.P. Drilling Analysis and Process Modelling of [0/90/0]

Oriented Glass Fiber Reinforced Epoxy Plastic (GFRP) Composite laminates, International Journal of Mechanical

and Material Sciences Research, 2016, volume 6, Number 1, pp. 1-11.

2. E. Uhlmanna F. sammlera, S. Richaraz, G. Reucherb, R. Hufschmiedc, A Frankc, B. Stawiszynskia, F. Protza

“Machining of carbon and glass fiber reinforced composites”, ScienceDirect, (IWF), Technical University Berlin,

2016, Procedia CIRP 46 ( 2016 ) 63 – 66.

3. Sharwan Kumar Sahu. Drilling of glass fiber reinforced polymer (gfrp) composites: multi response optimization

using grey relation analysis with taguchi’s method, national institute of technology Rourkela, 2015.

4. M.Sakthivel, S.Vijayakumar. Channankaiah, D.Athikesavan A Review on thrust force and torque in drilling of

glass fiber reinforced polymer composite, International Journal of ChemTech Research, 2014-2015, vol 7, No 6,

pp. 2786-2793.

5. Khashabha, U.A. Delamination in drilling GFR-thermoset composites, Composite Structures, 2004, 63, pp 313-

327.

6. K. Senthil Kumar, Abhilaks K J. Investigation of Drilling of Glass Fiber Reinforced Composite, International

Journal of Innovative Research & Development, October, 2015, Vol 4 Issue 11.

7. Patil Deogonda, Vijaykumar N Chalwa. Mechanical Property of Glass Fiber Reinforcement Epoxy Composites,

International Journal of Scientific Engineering and Research (IJSER), December 2013, Volume 1 Issue 4, ISSN

(Online): 2347‐3878.

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8. Shahabaz S M Rakesh Kumar, Nagaraj Shetty, Sharma S S Analysis of Delamination in Carbon Fiber Reinforced

Polymer Composite using Finite Element Method, International Journal of Innovative Research in Science,

Engineering and Technology(An ISO 3297: 2007 Certified Organization) , May 2016, Vol. 5, Special Issue 9.

9. Prasanna Ragothaman Annish Unnikrishnan Delamination analysis in drilling of composite materials using digital

image processing, regressionmodeling and fuzzy logic, International Journal of Mechanical and Production

Engineering, Nov.-2014, ISSN: 2320-2092, Volume- 2, Issue-11.

10. M. Ramesh, A. Gopinathan, C. Deepa Machining Characteristics of Fiber Reinforced Polymer Composites’,

Indian Journal of Science and Technology, Nov 2016, Vol 9(42).

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Figure1. a .Peel Up Damage b. Push Out Damage (page no. 1)

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Figure.2 Composite laminate (page no. 1)

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Figure.3 Delamination Factor (page no. 1)

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Figure 4. Hand Lay up Technique (page no. 3)

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Figure.5 GFRP Plate with (0/60/0) orientation (page no. 3)

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Figure.6 GFRP Plate with (0/45/0) orientation (page no. 3)

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Figure.7 GFRP plate with (0/90/0) orientation (page no. 3)

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Figure.8 CNC Vertical Drilling Machine (page no. 3)

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Figure.9 Probe to set [0/0/0] co-ordinates (page no. 3)

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Figure.10 Clamping system (page no. 3)

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Figure.11 Punching Operation (page no. 3)

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Figure.12 Drilling operation (page no. 3)

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Figure.13 Drilled plate (page no. 3)

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Figure.14 Sample drilled hole of 6mm diameter (page no. 3)

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Figure.15 Sample photo view of drilled hole (page no. 3)

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Figure.16 Sample photo view of drilled hole (page no. 3)

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Figure.17 Feed vs delamination behavior of GFRP plate with orientation (0/45/0) (page no. 4)

1.02

1.04

1.06

1.08

1.1

1.12

1.14

1.16

1.18

1.2

0 5 10 15 20 25

DEL

AM

INA

TIO

N

FEED

0/45/0 GFRP PLATE

DELAMINATION FACTOR OF 6MM DIAMETER


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0

0.2

0.4

0.6

0.8

1

1.2

1.4

0 10 20 30

DEL

AM

INA

TIO

N

FEED

0/60/0 GFRP PLATE



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0

0.2

0.4

0.6

0.8

1

1.2

1.4

0 10 20 30

DEL

AM

INA

TIO

N

FEED

0/90/0 GFRP PLATE



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Table 1 Properties of E Glass (page no. 3)

Properties E Glass

Modulus Of Elasticity in X direction

5e+10 Pa

Modulus Of Elasticity in Ydirection

1.2e+10 Pa

Modulus Of Elasticity in Z direction

1.2e+10 Pa

Poisson’s Ratio in XY 0.3

Poisson’s Ratio in YZ 0.3

Poisson’s Ratio in XZ 0.3

Shear Modulus in XY 5.6e+9 Pa

Shear Modulus in YZ 5.6e+9 Pa

Shear Modulus in ZX 5.6e+9 Pa

Density 2000 Kg/m3

Allowable Stress 400e+6 Pa

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Table 2 Delamination factor of 6mm and 8mm drill diameter of GFRP plates with (0/45/0) (0/60/0) and (0/90/0)

orientations (page no. 4)

SR NO

Speed

(rpm)

Feed

(mm/min)

Delamination Factor

of 6mm diameter

Delamination Factor of

8mm diameter

{0/45/0}

1

750 10 1.0333 1.0625

1500 15 1.1667 1.1875

2250 20 1.08333 1.125

{0/60/0}

2

750 10 1.25 1.125

1500 15 1.2 1.0875

2250 20 1.1667 1.00

{0/90/0}

3

750 10 1.25 1.0625

1500 15 1.1267 1.025

2250 20 1.0833 1.0125

final indian journal paper 123

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