SLIDING WEAR BEHAVIOUR OF GLASS FIBER REINFORCED EPOXY RESIN COMPOSITE AND OPTIMIZATION

GOVERNMENT COLLEGE OF TECHNOLOGY

DEPARTMENT OF PRODUCTION ENGINEERINGSLIDING WEAR BEHAVIOUR OF

GLASS FIBER REINFORCED EPOXY RESIN COMPOSITE AND

OPTIMIZATIONPROJECT TEAM MEMBERS:

R.MITHILESH KUMAR(0715123)NARESH KUMAR SENAPATI(0715125)

S.NELSON MANDELA(0715126)M.PRADEEP RAJA(0715130)

N.SUBBIAH @ SURESH(0715147)A.KAMALAKKANNAN(0715L03)

UNDER THE GUIDANCE OF:Mr. S. SRINIVASA MOORTHY, APPE

SYNOPSISThe present work includes the processing, characterization and study of the sliding wear behaviour of a e glass-epoxy composite. The composite with varying fibre length of 1cm, 2cm and 3cm along with different fibre content of 30wt%, 40wt% and 50wt % are used. By volume fraction method, the weight percentage of fiber, unsaturated polyester resin is calculated, and the polymer composite is fabricated by hand layup method.

The experimental investigations are carried out to investigate properties of unsaturated polyester composites under the wear test.

Then Taguchi’s experimental design approach is carried out to make a parametric analysis of sliding wear behaviour.

The systematic experimentation leads to determination of material variables that predominantly influence the wear rate.

The regressive analysis is carried out to determine the non-linear analysis for the prediction of the optimized model.

INTRODUCTION Composite materials are engineering materials

made from two or more constituent materials that remain separate and distinct on a macroscopic level while forming a single component.

There are two categories of constituent materials: matrix and reinforcement. At least one portion of each type is required.

The matrix material surrounds and supports the reinforcement materials by maintaining their relative positions.

The reinforcements impart their special mechanical and physical properties to enhance the matrix properties.

MATERIALS USED FOR FABRICATION OF COMPOSITES

FIBER : FIBER : E GLASS FIBRE E GLASS FIBRE ((ALUMINO-BOROSILICATE GLASS WITH LESS ALUMINO-BOROSILICATE GLASS WITH LESS THAN THAN 11 WT% ALKALI OXIDES, MAINLY USED WT% ALKALI OXIDES, MAINLY USED FOR GLASS-REINFORCED PLASTICS )FOR GLASS-REINFORCED PLASTICS )RESIN :RESIN :UNSATURATED UNSATURATED

POLYESTER RESIN POLYESTER RESINACCELERATOR : ACCELERATOR : ETHYL METHYL ETHYL METHYL

KETONE KETONECATALYST : CATALYST : COBALT NAPHTHENATECOBALT NAPHTHENATE

METHODOLOGYCollection of E-glass fiber, resin and

accelerator.Mould preparation.Mixing the Unsaturated polyester resin and

accelerator with a ratio of 1:1.5.Preparation of the specimen.Conducting wear test on specimen.Interpretation of wear test results using

Taguchi and Regression model analysis.

COMPOSITION

S .NO FIBRE

LENGTH

(cm)

FIBRE

CONTENT

(wt %)

RESIN

(wt %)

C1 1 30 70

C2 2 40 60

C3 3 50 50

COMBINATIONS FABRICATEDSl.No FIBRE LENGTH FIBRE CONTENT RESIN

1 1 30 70

2 1 40 60

3 1 50 50

4 2 30 70

5 3 30 70

6 2 40 60

7 3 40 60

8 2 50 50

9 3 50 50

FABRICATIONHAND LAY-UP OPERATION:Pattern preparation.Weighing of fibre, resin are made as per calculations.Mixture of (resin + catalyst + accelerator) is made.Wax coating .The fibers are laid in the pattern and the mixture is applied for bonding.After fabrication the composite material is left for curing for 24 hours.After curing process, cutting is done as per required dimensions.

PATTERN WITH WAX COATING

MATERIAL LEFT FOR CURING

FABRICATED PIECE AFTER CUTTING TO REQUIRED DIMENSIONS

WEAR TESTWear is erosion or sideways displacement of

material from its derivative and original position on a solid surface performed by the action of another surface.

The definition of wear may include loss of dimension from plastic deformation if it is originated at the interface between two sliding surfaces.

The wear test is being conducted on the specimens prepared by the hand lay-up method

WEAR TESTING MACHINEThe machine used for conducting the wear test

is DUCOM TRIBOMETER. The DUCOM TRIBOMETER uses a pin-on-disk system to measure wear.

The unit consists of a gimbaled arm to which the pin is attached, a fixture which accommodates discs upto 165mm in diameter and 8mm thick, an electronic force sensor for measuring the friction force, and a computer software (WINDUCOM) for displaying the parameters, printing, or storing data for analysis.

The motor driven turn table produces upto 2000rpm. Wear is quantified by measuring the wear groove with a profilometer and measuring the amount of material removed.

FEATURES AND SPECIFICATIONPARAMETER MINIMUM MAXIMUM UNIT

PIN SIZE 3 12 mm

DISC SIZE 165*8 mm thick mm

SLIDING SPEED 0.05 10 m/s

DISC ROTATION 200 2000 rpm

NORMAL LOAD 0 200 N

FRICTIONAL

FORCE

0 200 N

WEAR 0 2 mm

TRACK RADIUS TO BE SET MANUALLY mm

WEAR TESTING MACHINE

TESTING PROCEDUREThe specimen to be tested is placed on the

turn table fixture. The test variables sliding velocity, normal load, distance and time duration are specified.

The normal load is applied to the pin using a system of weights. Rotating the turntable while applying this force to the pin includes sliding wear as well as friction force.

TEST RESULTSAPPLIED FORCE FIBER CONTENT VELOCITY

WEAR RATE

20 30 1 0.00519

20 40 3 0.01745

20 50 5 0.003638

30 30 3 0.004299

30 40 5 0.003768

30 50 1 0.005574

40 30 5 0.00797

40 40 1 0.02955

40 50 3 0.004256

TAGUCHI METHODTaguchi defines the quality of a product, in

terms of the loss imparted by the product to the society from the time the product shipped to the customer.

Taguchi method uses a special design of orthogonal arrays to study the entire parameter space with a small number of experiments only.

The experimental results are then transformed into a signal-to-noise (S/N) ratio.

STEPS INVOLVED IN TAGUCHI METHODDetermination of the number of levels for the

design.Selection of the appropriate orthogonal array and

assignment of design parameters to the orthogonal array.

Conducting of the experiments based on the arrangement ofthe orthogonal array.

Analysis of the experimental results using the S/N and ANOVA analyses.

Selection of the optimal levels of design parameters.

CATEGORIES OF QUALITY CHARACTERISTICNormal is bestSmaller is betterLarger is better

For wear test smaller the better quality characteristic is preferred for analysis.

Smaller the better characteristic equation: S/N= −10 log (1/n) (∑y2)

ORTHOGONAL ARRAYAn orthogonal array is a type of experiment

where the columns for the independent variables are orthogonal to one another.

LEVELS AND FACTORS

Code Factor

Levels

1 2

3

AApplied force in

N20 30 40

BFiber content in

wt%30 40 50

C Velocity in m/s 1 3 5

L9 ORTHOGONAL ARRAY AND VALUESTrial Levels

1 2

3

Wear rate

1 20 30 1 0.00519

2 20 40 3 0.01745

3 20 50 5 0.003638

4 30 30 3 0.004299

5 30 40 5 0.003768

6 30 50 1 0.005574

7 40 30 5 0.00797

8 40 40 1 0.02955

9 40 50 30.004256

S-N RESPONSE FOR WEAR

  Mean S/N ratio

Parameter Level1 Level 2 Level 3 Delta Rank

Applied 

Force45.000 38.077 47.094 124.632 3

Fibre 

content (wt

%)

 43.215

46.962

39.994

133.499

1

Velocity

40.454

43.306

46.411

128.345

2

The following table shows the signal to noise response for wear

ANALYSIS OF VARIANCEThe purpose of the analysis of variance

(ANOVA) is to investigate the design parameters significantly affect the quality characteristic of a product or process.

ANOVA can be useful for determining influence of any given input parameter from a series of experimental results by design of experiments for machining process and it can be used to interpret experimental data.

ANOVA TABLE

SymbolCutting

Parameter D.O.F S.S. M.S. F Contribution

1 AF 2 72.981 36.491 1.064 22.218

2 FC 2 133.618 66.809 1.947 40.678

3 V 2 53.260 26.630 0.776 16.214

Error 2 68.622 34.311 20.891

Total 8 328.482 164.241 100.000

FACTORS INFLUENCING WEAR

RESULTS FROM TAGUCHI ANALYSISFrom the Taguchi result fibre content is most

significant factor for wear.The results of ANOVA revealed that fibre

content is the main parameter which has greater influence on wear.

The wear resistance increases with the increase of fibre content.

REGRESSION MODELLING AND ANALYSISThe statistical tool, regression analysis helps

to estimate (predict) the value of one variable from the given value of another.

Regression Models

Regression models involve the following variables:

Unknown parameters, βIndependent variables, XDependent variables, Y

TYPES OF REGRESSIONLinear RegressionNon-linear Regression

Non-Linear Regression AnalysisThe model function is not linear in the parameters the sum of squares must be minimized by an iterative procedure. Most of the researchers use the Nonlinear regression models in various applications.

REGRESSION MODEL RESULTSNonlinear Regression Summary Statistics     Dependent Variable WR  Source                        DF  Sum of Squares  Mean Square Regression                     4         .09187         .02297  Residual                         5   1.532781E-03   3.065562E-04      Uncorrected Total         9         .09340                (Corrected Total)         8         .07230  R squared = 1 - Residual SS / Corrected SS = 0.97880                                                                        Asymptotic 95 %                                           Asymptotic     Confidence IntervalParameter   Estimate     Std. Error            Lower         UpperK            8.30330E-13     9.41564E-12  -2.33733E-11  2.50340E-11   X           -2.046056436   .938599113  -4.458802268   .366689396 Y            7.744994220    2.452698704   1.440131484 14.049856957 Z            1.513272257      866626694  -.714462582  3.741007096 

REGRESSION MODEL RESULTS

It is seen that the value of R square is 0.97880, which ensures that the generated non-linear mathematical model for wear resistance is optimal.

CONCLUSIONThe unsaturated composite of e-glass fiber and

epoxy resin is fabricated using the hand lay-up technique.

The weight percentage of different compositions is calculated by volume fraction method.

The wear resisting property is characterized by conducting wear test on Ducom Tribometer.

Applied force, fiber content and velocity are influencing factors. It is observed that the wear resistance increases with increase in fiber content.

Taguchi’s analysis is carried out to find out the most influencing factor and optimization is done by considering the values from signal to noise ratio relationship, analysis of variance.

Regression modelling and analysis is also carried out to validate the wear test results.

By using the non-linear regression analysis method iterations are carried out and the final result ensures the optimization.

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