analysis of impacting wave using piezoelectric sensor for

Journal of Engineering and Applied Sciences 14 (Special Issue 7): 10207-10215, 2019ISSN: 1816-949X© Medwell Journals, 2019

Analysis of Impacting Wave using Piezoelectric Sensor fora Pressurized Thin Aluminum Plate Covered with a Composite Material

Ali Kamil JeburDepartment of Electromechanical Engineering, University of Technology,

Baghdad, Iraq

Abstract: A circular thin aluminum plate is coated by a composite material from a wood/polypropylene, madefrom a different wood flour percentage weight (25, 50 and 75%) and grain size (50, 100 and 150 μm), a constantinternal pressure is subjected below the thin aluminum plate and impacted in upper coated surface with adifferent weight of a stainless steel ball which is freely dropped. The Light Dependent Resistor (LDR) Arduinosensor system, digital dial gage and piezoelectric sensor are used and controlled by an Arduino hardware andsoftware for measuring and recording the vibrating data for analyzing the response vibrated signal after impact.The vibration signal analysis shows the increasing of the damping ratio 0.085-0.35 after the free drop impactand a decreasing in impacted time during increasing in weight of impacted load with type of wood grain size150 μm and with a wood flour 75 wt.% in the raise. The deformation results are nearly agree withthe Roark’s formulas, more than using mindlin plate theory which help to understand the vibrationbehavior of this composite material under a free drop impact test and to make a suitable shockabsorber layers.

Key words: Composite material, impact, piezoelectric sensor with arduino hardware, vibration control, LDR,mindlin plate

INTRODUCTION

Polypropylene is used as polymer matrix with areinforcing filler like liquefied tropical wood to madeLiquefied Tropical Wood/Polypropylene composites(LTW/PP), under tensile test the composites wereevaluated and it seems to be that the modulus of elasticityis increased due to the addition of these filler LiquefiedTropical Wood (LTW) in the composites which isprepared with 10, 20, 30 and 40 wt.% (Idrus et al., 2011).In Polypropylene (PP) it can be reinforced with woodflour 0, 5, 10 and 20 wt.% to increase stiffness and impactresistance which does not have a large change as afunction of wood content and at large wood content thestiffness is increasing and led to a small fracturetoughness with micromechanical deformation processesand the deformation processes, generally, depend on thestrength of polypropylene/wood interaction. in the woodcontents range (50-60 wt.%), the large impact resistancecannot be prepared in composite (Keledi et al., 2012).

Because of the powder particles used in compositematerial which may represent points for a localized stressconcentration from which the failure will begin. Underimpact test, the impact strength decreases with increasingof powder particles weight fraction and for the all groupsinvestigated of composite materials compared to theimpact strength of the matrix, all of these results have

been reported mainly due to the reduction of elasticity ofmaterial due to powder addition and thereby reducing thedeformability of matrix and in turn the ductility in the skinarea (Mohammed, 2015). The impact strength ofAl6061/SiC metal matrix composites reinforced withnanoparticles of weight percentage (3, 6, 9 and 12%) wasstudied. The improvement of impact strength wasobserved with increasing the weight percentage of SiCnanoparticles. The maximum strength is showed with the12 wt.% nano SiCp aluminum composites. It is seen thatthe impact energy of the composites increase graduallywith filler content increasing from 3-12 wt.%(Mohammed and Hanoos, 2017). With mechanical testingof material like impact test is one of the test used to testmechanical properties of composites and the Charpyimpact is one of impact type method. As a filler materialin composites like a wood flour is used to made a materialwith more rigid and brittle but due to the water absorptionand swelling the strength is decreased and the impactstrength is increased (Kallakas et al., 2015). Theimpulsive forces as being forces of very large magnitudethat act over a very small interval of time but cause asignificant change in the momentum. Impulsive forces arethose generated when a steel ball hit a metallic aluminumplate (with and without coating), typical time intervals ofimpulses occur during the impact start from 0.18-0.2 msecfor steel impacted test (Young and Budynas, 2002;

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J. Eng. Applied Sci., 14 (Special Issue 7): 10207-10215, 2019

Peraire and Widnall, 2003). Piezoelectric sensor is usedin experiments with an error between 3.0 and 7.5% errorin the experimental frequencies which is lower than theanalytical solution using vibrational equations for thealuminum plate shaker testing and the dynamicsparameters of composites plate with the bending modalfrequencies are solved by Euler theory which predictstends to be about 5% larger than experimental results indeflection for any amplitude and frequency in plate testingwith the Ritz assumption mode method for analyticalsolution for the effective of damping ratio as a ratio ofenergy absorbed to total system energy which predictslinear piezoelectric effects (Tremaine, 2012). Polystyrene,low density polyethylene, polypropylene and polymethacrylate are the polymer materials which areinvestigated under the impact test and performed at roomtemperature according to ISO 179 each sample wastested for 3 times and average results have been reportedand represented that the increasing of PP content inpolymer makes the impact properties and fracturetoughness increases for blends system (Salih et al.,2015).

The aim of this research is to study the effect of thewood flour percentage weight in wood/polypropylenecomposite material on the response of vibrated signalgenerated due to the impact test. This resultsmeasured by a digital dial gage and a piezoelectric sensorwhich are controlled by an Arduino hardware andsoftware.

Mathematical equations: For free drop impactingbodies, it is necessary to calculate the parametersrequirements velocity, acceleration just before impact andthe impacted force just before impact. These set ofequations are used for impacting contacted time τpulse =0.0005-0.02 for different material (Metz, 2007):

(1)pulse

8gh w2gh ; a ; F ma a

t g

Using Roark’s formulas, the maximum stress under staticload is (Young and Budynas, 2002):

(2) max sta 2

F D1+v 0.485 in +0.52

t 2t

And the static maximum deflection at the center of thecircular plate using Roark’s formulas:

(3)2

max sta R 3

0.05425 FD

Et

For using thin plate in tank vessel by using Mindlin’splate theory for thin circular plate which is Clamped 360°and a uniformly distributed load is subjected, themaximum elastic deflection and stresses are calculated byGujar and Ladhane (2015). Dr: flexural rigidity of theplate which can be calculated as follows:

(4) 3

r 2

EtD

12 1 v

By using Mindlin’s plate theory for thin circular platewhich is Clamped 3600 and a concentrated load issubjected, the maximum elastic deflection and stresses arecalculated by Gujar and Ladhane (2015):

(5)r max max2 2

3P 3vP;

2 t 2 t

For σθ-max<σr-max; then the study should take maximumstress for load safety during calculations to avoid thefailure of the material:

(6)2

max sta Mr

Pr

16 D

Roark and mindlin formulas: In composite materials itis necessary to change the modulus of elasticity in Eq. 4which is represented the equivalent modulus of elasticitywhen determine the properties of a composite laminate foreach component the volume fractions should be knownand calculated using the rule of mixtures as shown inEq. 7 (Gibson, 2011):

(7)c 1 1 2 2E E V +E V

Where:Ec = The composite modulus of ElasticityE1,2 = The modulus of Elasticity for first and second

materialV1,2 = The Volume fraction for first and second

material

After impact it seems that the plate continue vibratedwith a ununiformed wave until stop vibrate whichdifferent from impact to another due to the different typeof composite materials which dependent on the w% of thewood flour, so, it is necessary to start from the equationsof motion after impact can easily be put in the classicalmatrix as (Anonymous, 2016):

(8) Mx+Cx+Kx F t

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For the damping value can be estimatedapproximately by measuring the logarithmic decrement ofeach mode separately and through a band-pass filtercentered at the particular frequency of interest, it cansolved experimentally by filtering the system responsesignal for better estimation of damping and this methodsis recommended. Logarithmic decrement is defined as thenatural logarithm of the ratio of any two consecutiveamplitudes in the time domain (Anonymous, 2016):

(9)1 d

n d 22

ln x 2 TT

x 1-

(10)2d n 1-

(11)d 2d n

2 2 1T

1-

Where:ζ = The damping ratioωn = The natural frequencyTd = The damping period

Critical damping ratios for the first 10 or so, modesrange from 0.04-0.8%. For the stiffened plate, it variesfrom 0.05-2% even though aluminum is used throughoutby using the logarithmic decrement is dimensionless fromthe dimensionless damping ratio ζ by the displacements δresulted and measured theoretically and experimentally(Bakir, 2004):

(12)1

2 22

x, where ln

x4 +

The measuring of the natural frequency and dampingcoefficient for a mode of component vibration can bemeasured by the force vibration response of the impactedsystem by measuring the bandwidth Δω and the maximumamplitude like the logarithmic decrement which gave theforced harmonic response as a measure of the damping insystem with taken in the consideration that the maximum,measured by apply in Eq. 13 and 14 (Chauhan et al.,2009; Verros et al., 2005):

(13)max2

(14)nc 2m

MATERIALS AND METHODS

Experimental materials analysisMaterial preparation: According to the procedures inASTM standards D 638 and D 790 for tensile tests and

Table 1: Chemical composition for aluminum plate usedElements Composition (%)Magnesium (Mg) 4.0-4.90Manganese (Mn) 0.40-1.00Iron (Fe) 0.40Silicon (Si) 0.0-0.40Titanium (Ti) 0.05-0.25Chromium (Cr) 0.05-0.25Copper (Cu) 0.10Zinc (Zn) 0.0-0.10Aluminium (Al) Balance

Table 2: Mechanical properties for aluminum plate usedProperties ValuesProof stress (MPa) 110Ultimate strength (MPa) 250Density (kg/m3) 2650Hardness Brinell (HB) 73Modulus of elasticity (GPa) 70Passion ratio 0.39

Table 3: Mechanical properties of polypropylene usedProperties ValuesTensile strength (MPa) 25Density (kg/m3) 905Elongation at break (%) 150modulus of elasticity (GPa) 1-1.4Notched izod impact (kJ/m) 0.07Rockwell “R” scale 80

Fig. 1: Comparison between three grain sizes (50, 100, 150 μm) of flour wood with a three deferentpercentage weight (25, 50, 75 wt.%) inpolypropylene as a matrix

Izod impact strength were measured by Instron impactpendulum tester under ASTM D 256 with notchedspecimens depth = 2 mm at 50% relative humidity androom temperature at 24°C (Fig. 1).

To understand the type of material testing, it needs toanalysis the tested metal pleat, especially, chemicalcomposition and the mechanical properties as shown inTable 1-3, respectively.

From Table 1 and the recognition of this plate is analuminium alloy 5086 and the experimental mechanicalproperties for aluminium alloy is tested as in Table 2.From the standard in which describe the properties of thepolypropylene used as a matrix and these values are nearto the minimum values in the commercial polypropyleneproduction used the properties of polypropylene is a (Semi-rigid, Translucent, Good chemical resistance,

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Fig. 2: Testing scheme process as consideration SDOF under impact test

Fig. 3: a-d) Computational experimental equipment with electrical measuring equipments: 1) The LCD monitor; 2) Theduct for covering the test; 3) The Arduino hardware with connectors wires; 4) The frictionless tube for verticaldirection path of impactor; 5) The supporters; 6) The LDR sensors; 7) The Digital Dial Gage (DDG); 8) Thesupporter of the Digital Dial Gage (DDG); 9) The magnetic supporter for the Digital Dial Gage (DDG); 10) Thepiezoelectric sensor; 11) The pressurized thin aluminum plate; 12) The steel base container for air pressure andsupporters; 13) The computer interface for data recording; 14) The compressor for air pressure supply and 15)The steel ball for free drop test

Tough, Good fatigue resistance, Integral hingeproperty, Good heat resistance) and as shown inTable 3. Three type grain size 50, 100, 150 μm of woodflour are mixed with a deferent percentage weight

(25, 50, 75 wt.%) in polypropylene as a matrix (Fig. 3).The ASTM standards D 638 for tensile tests theresults are shown in Fig. 1 and Table 3 for materialtesting.

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Steel ball

Glass tube of guide the steel ball Steel

ball

F (t)

X (t)

K for composite materials

K for thin Aluminum plate Thin aluminum plate

Composite materials wood/polypropylene

Air pressure

(a) (b) (c)

(d)


Fig. 4: Connection of piezoelectric sensor with Adruino UNO

Experimental testing system: A simple equipment isdesign according to the idea of experiment material testas shown in Fig. 2 and manufactured for testing andgetting the necessary required parameters for calculationswhich seems to the single degree of freedom withexcitation force which appears from the impact test.The composite material with a thin aluminum pressurizedunder internal pressure as a tire of car which <100 barsubjected to the ramp or shock during running onununiformed road.

The study need to measure the velocity for a freedrop steel ball by Light Dependent Resistor (LDR)Arduino sensors system which are connected to theArduino hardware and read the velocity value in the LCDmonitor as shown in Fig. 3a and b for a vertical distance400 mm with a friction from a contact with frictionlessclass tube which used for the insure that the verticalcontact angle is 90° with the surface of compositematerial which the deformation is measured by a digitaldial gage as shown in Fig. 4 and 5. On the thin aluminumplate with and without composite materials with totalthickness not more then 5 mm. Then the system isassembled with these all required equipment for study andimpact test as shown in Fig. 3d which help to record allthe output resulted data for comparison in the study byconnected with a computerized system.

Fig. 5: Impact speed and time connection using LightDependent Resistor (LDR) circuit connectiondesign

RESULTS AND DISCUSSION

For the 75 wt.% of wood flour content with a goodadhesion the results have increasing in a stiffness of the

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composites which improve the strength and the woodcontent in composite haven’t much recognized changingin impact resistance, especially in 25 and 75 wt.% ofwood content. The effect of particle size of thewood flour in the polypropylene as a matrix, for the50, 100 and 150 μm as shown in Fig. 1 that withincrease in the size wood flour particles observeddecreasing in modulus of elasticity and a smaller drop inelastic-impact strength because of the increase inperformance-surface filling which lead to choose the150 μm with 75 wt.% for impact testing to get anexpected acceptable results in damping ratio to avoid thecontinuity of vibration with a good shock absorptionsystem (Fig. 6-8).

From Fig. 9, the experimental results agree with thetheoretical results which agree with the method had donby Metz (2007) but its clear that in light weight is more

Fig. 6: Impacted load results recorded from piezoelectricsensor

Fig. 7: Theoretically deformations results just foraluminum thin plate 0.6 mm with experimentaldeformations results by DDG sensor recorded asa bar chart

Fig. 8: Theoretical and experimental deformation withcoted composite material 2 mm

acceptable than heavy weight because of the sensitiveaccuracy of the piezoelectric diaphragms used in thisstudy which is a piezoelectric ceramic disks adhered to ametal plates of brass or nickel-alloy, this commercialpiezoelectric sensor dose not accurately recordeddata, especially, if the impact force more than1000 N.

The impacted loads divided into light and heavyweight Fig. 6 which recorded as a response impactedsignal from piezoelectric sensor and LDR for measuringthe experimental velocity of free drop impactors steelballs. And by using Roark’s formulas and Mindlin’splate theory equations and the experimental deformationresults aluminum thin plate without the compositematerial Fig. 7 and aluminum with composite material layers until 5 mm as in Fig. 8-10 from the Digital Dial Gage (DDG) which are used for measurementcomparison between theories. These phenomena has donebecause of the changing the system shock absorber byadding the air inside the thin coated plate and appears theeffect of the viscous damping coefficient and the systemhas got the mass-spring-damper single degree of freedom(Fig. 11 and 12).

Piezoelectric sensor signal resulted from Arduino: Foracceleration 7003.5 m/sec2 with velocity 2.8 m/sec with40 cm height of free drop of bodies weight increasing(0.022, 0.045, 0.17 and 0.37 kg) with decreasing

Fig. 9: Theoretical and experimental deformation withcoted composite material 2.4 mm

Fig. 10: Theoretical and experimental deformation withcoted composite material 5-6 mm

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Fig. 11: Impacted force with natural frequency with andwithout effected internal pressure

Fig. 12: Frequency impacted force with damping ratiounder internal pressure and composite materials

1-0.29 msec in time of impacted contact. The resultedparameters have got from the analyzing the wave data as

Fig. 13: Impact signal with 0.022 kg with impact contacttime 1 msec

Fig. 14: Impact signal with 0.045 kg with impact contacttime 0.6 msec

shown in Fig. 11 and 12, the impact load, naturalfrequencies and the damping ration after adding theinternal pressures inside the coated thin aluminumplate.

Figure 13-16 with analysis of the signalsproduced by different impacted loads which haveincreasing in weight and first maximum amplitudefor first impact and second and third sometimebecause of the additional jumping after first touch with surface on the plate. The impacted wave signalanalysis from sensors analysis with Microsoft Excelshown in Fig. 13-16.

For improving the agreement of choosing the materialwith 75 wt.% of a wood/polypropylene compositematerial with a wood flour percentage weight (25, 50 and75%) and grain size 150 μm under internal pressure and

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0.7

0.6

0.5

0.4

0.3

0.2

0.1

0.0

-0.10.00000 0.00100 0.00200 0.00300 0.00400

Dis

plac

emen

ts (m

m)*

10

Time (msec)

0.8

0.6

0.4

0.2

0.0

-0.2

0.00000 0.00100 0.00200 0.00300 0.00400

Dis

plac

emen

ts (m

m)*

10

Time (msec)




Fig. 17: Impact signal for low weight with 0.022 kg withimpact contact time 1 msec, AL+ composite75%, E = 1.5 GPa

Fig. 18: Impact signal for heavy weight with 0.37 kg withImpact contact time 0.29 msec, Al+ composite75%, E = 1.5 GPa

impact test with low and heavy weight impacted load as shown in Fig. 17 and 18 which show the completelyimagination of the all impacted signals that help tounderstand of the behavior of the materials which coatedwith different wt.% of wood flour that is shown all signalsof impacted test for low and heavy impacted load and theincreasing of contacted impacted time 1 msec in the lowimpacted load with low value of displacement in platedeformation.

CONCLUSION

For a clamped isotropic circular thin aluminum plateunder pressure and coated with a wood flour in thepolypropylene as a matrix composite material underimpact analysis as a free drop bodies by usingexperimental and analytical method are compared andhave some conclusions can be recognized:

The results in polypropylene with wood flour 75%with grain size 150 μm, gives a good material with anacceptable impact strength under acceptable dampingratio between 0.085-0.35. Under these conditions thiscoated materials may be find a large applications inareas where reduction of vibration is necessaryrequired in general the experimental results ofdeformation due to the impacted load are nearly agreewith the deflection at the center of the clamped circularthin plate using Roark’s formulas, more than usingMindlin plate theory.

RECOMMENDATIONS

The increasing of impacted load without any effect ofthe internal pressure cause decreasing in frequency with

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2.0

1.5

1.0

0.5

0.0

-0.5

Dis

plac

emen

ts (m

m)*

10

3.0

2.5

2.0

1.5

1.0

0.5

0.0

-0.5

-1.0

Dis

plac

emen

ts (m

m)*

10

Time (msec)

AL-wave signal

Al-composite 25%

Al-composite 50% Al-composite 75%

3.0

2.5

2.0

1.5

1.0

0.5

0.0

-0.5

-1.0

Dis

plac

emen

ts (m

m)*

10

Time (msec)

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0.0

-0.1

Dis

plac

emen

ts (m

m)*

10

Time (msec)

Al-wave signal

Al+composite 25%

Al+composite 50% Al+composite 75%


a good indication for the increasing in damping ratio of asmall natural frequencies for impacted load but it will bemore and higher with the effect of internal pressure belowof the coated thin aluminum plate. It can conclude that thedecreasing of impact contact with increasing of theimpacted load and damping frequency, these resultedrelations because of the type of composite materials hadcoated the thin aluminum plate and because of the sheardeformation was not considered in the thin plate but if theplate was thick then the effect of shear deformationshould be more considerable and effected on the resultsobtained.

REFERENCES

Anonymous, 2016. Basics of structural vibration testingand analysis. Crystal Instruments Inc., Santa Clara,California. https://www.crystalinstruments.com/basics- of-structural-vibration-testing-and-analysis/

Bakir, P.G., 2004. Vibration of single degree of freedomsystems. Pelin Gundea Bakir, Artvin, Turkey.

Chauhan, S., A. Karmarkar and P. Aggarwal, 2009.Damping behavior of wood filled polypropylenecomposites. J. Appl. Polym. Sci., 114: 2421-2426.

Gibson, R.F., 2011. Principles of Composite MaterialMechanics. 3rd Edn., CRC Press, Boca Raton, Florida, USA., ISBN-13:978-1439850053, Pages: 683.

Gujar, P.S. and K.B. Ladhane, 2015. Bending analysis ofsimply supported and clamped circular plate. Intl. J.Civ. Eng., 2: 69-75.

Idrus, M.M., S. Hamdan, M.R. Rahman and M.S. Islam,2011. Liquefied tropical wood/polypropylenecomposites: Preparation and physico-mechanicalproperties. Mater. Phys. Mech., 11: 126-136.

Kallakas, H., T. Poltimae, T.M. Suld, J. Kers andA. Krumme, 2015. The influence of acceleratedweathering on the mechanical and physical propertiesof wood-plastic composites. Proc. Est. Acad. Sci.,64: 94-105.

Keledi, G., A. Sudar, C. Burgstaller, K. Renner and J. Moczo et al., 2012. Tensile and impactproperties of three-component PP/wood/elastomercomposites. Exp. Polym. Lett., 6: 224-236.

Metz, R., 2007. Impact and Drop Testing with ICP ForceSensors. PCB Piezotronics, Inc., Depew, New York,USA.

Mohammed, A.A., 2015. Investigation of tensile andimpact of composite materials reinforced with naturalmaterials. Eng. Technol. J., 33: 919-933.

Mohammed, R.H. and M.M. Hanoos, 2017. Theeffect of nanoparticles additives on impactstrength of metal matrix composites. Eng. Technol.J., 35: 37-40.

Peraire, J. and S. Widnall, 2003. Lecture L9-LinearImpulse and Momentum, Collisions. In: EngineeringMechanics: Dynamics, Meriam, J.L. and L.G.Kraige (Eds.). Wiley Publishing Company,Hoboken, New Jersey, USA., ISBN:9780471266068,pp: 1-13.

Salih, S.E., J.K. Oleiwi and R.A.A. Ameer, 2015.Comparing effect of adding LDPE, PP, PMMA onthe mechanical properties of polystyrene (PS). Eng.Technol. J., 33: 1450-1461.

Tremaine, K.M., 2012. Modal analysis of compositestructures with damping material. Master Thesis,California Polytechnic State University, San LuisObispo, California, USA.

Verros, G., S. Natsiavas and C. Papadimitriou, 2005.Design optimization of quarter-car modelswith passive and semi-active suspensionsunder random road excitation. Mod. Anal., 11: 581-606.

Young, W. and R. Budynas, 2002. Roark’s Formulas forStress and Strain. 7th Edn., McGraw-Hill, New York,ISBN-13:978-0070725423, Pages: 832.

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analysis of impacting wave using piezoelectric sensor for

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