research article thermal stresses analysis and ... - hindawi

Research ArticleThermal Stresses Analysis and Optimized TTP Processes toAchieved CNT-Based Diaphragm for Thin Panel Speakers

Feng-Min Lai and Chang-Yi Peng

Department of Materials Science and Engineering Da-Yeh University Changhua 51591 Taiwan

Correspondence should be addressed to Feng-Min Lai fengminmaildyuedutw

Received 6 March 2016 Accepted 7 June 2016

Academic Editor Ying-Lung D Ho

Copyright copy 2016 F-M Lai and C-Y Peng This is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work is properlycited

Industrial companies popularly used the powder coating classing and thermal transfer printing (TTP) technique to avoid oxidationon the metallic surface and stiffened speaker diaphragm This study developed a TTP technique to fabricate a carbon nanotubes(CNTs) stiffened speaker diaphragm for thin panel speaker The self-developed TTP stiffening technique did not require a highcuring temperature that decreased the mechanical property of CNTs In addition to increasing the stiffness of diaphragm substratethis technique alleviated the middle and high frequency attenuation associated with the smoothing sound pressure curve of thinpanel speaker The advantage of TTP technique is less harmful to the ecology but it causes thermal residual stresses and someunstable connections between printed plates Thus this study used the numerical analysis software (ANSYS) to analyze the stressand thermal of work piece which have not delaminated problems in transfer interface The Taguchi quality engineering methodwas applied to identify the optimal manufacturing parameters Finally the optimal manufacturing parameters were employed tofabricate a CNT-based diaphragm which was then assembled onto a speaker The result indicated that the CNT-based diaphragmimproved the sound pressure curve smoothness of the speaker which produced a minimum high frequency dip difference (ΔdB)value

1 Introduction

The thermal transfer printing (TTP) technique is coatingmaterials to combine on the metallic surface in high thermalenvironment This study explores thermal stresses analysisof coating to make the coating boundary have a goodcombination especially The research of thermal conductionin composite materials is various in the recent years Ozisikindicated that the composite structures are formed by two ormore plates the connection between any two plates tends tohave the problem of thermal resistance [1] Previous studieshave reported that themagnitude and distribution of thermalresidual stress can be adjusted by selecting the appropriatematerial combination and controlling the compositional gra-dient Shaw used the multilayer composite plates with differ-ent materials to form the elastic module and coating them ondifferent plates and found that different coating thicknesseswill influence the characteristics of thermal residual stresses[2] Ozel et al used the finite element method (FEM) to

simulate various ceramic materials which are analyzed bytheir thermal stresses under the very high temperature [3]

Current technological products including speakers aremostly lightweight Speakers have become an integral part ofpeoplersquos everyday life and are prevalently applied in a varietyof products such as television computers tablet computersand mobile phones To fulfill market demands and customerneeds for thinner panel speakers with excellent sound qualityproblems concerning middle and high frequency attenuationin thin panel speakers must be resolved The diaphragmin thin panel speaker is the key component of a speakerThe mechanical property of a diaphragm directly influencescrucial acoustic characteristics of the speaker (including thesound pressure level (SPL) and frequency range)

Typically the major material of the diaphragm is coarsepaper However the lack of stiffness produces unclear soundat middle and high frequency Therefore polyethylene naph-thalate (PEN) pasted on coarse paper orAl foil pasted on formmaterials has been studied to enhance the stiffness However

Hindawi Publishing CorporationJournal of NanomaterialsVolume 2016 Article ID 8243605 10 pageshttpdxdoiorg10115520168243605

2 Journal of Nanomaterials

poor adhesion and overweight problem occur and limit theirapplication It is reported that using CNTs as an additive canenhance the mechanical property of resin [4ndash6] Comparedwith regular polymer CNTs have lower expansion coefficientwhich reduces the residual stress in laminated polymercomposites In addition CNTs have favorable strength andstiffness and are capable of changing material propertiessuch as electrical and thermal conductivity However paststudies also have observed that mixing high-concentrationCNTs with epoxy lowers the mechanical strength of theepoxy which is primarily attributable to the aggregation ofthe CNTs and the formation of hollow pores in the epoxy[7 8] Regardless the composite coating containing CNTsand epoxy has not been studied for using as the diaphragmin thin panel speaker

In this study we self-developed a TTP technique toprepare the diaphragm in thin panel speaker TTP is a man-ufacture through which coatings are bonded to the surfaceof a transfer material at temperature from 80∘C to 120∘C[9] The composite paste of CNTs and epoxy was first roller-pressed onto a polyethylene naphthalate (PEN) substrate toreinforce the PEN after which the backside of the PEN wascoated with hot melt adhesive (HMA) The fabricated TTPpaper (CNTs+epoxyPENHMA) was cut into adequate sizeand shape Next a TTP machine was used to locally orfully press TTP paper onto a coarse paper to manufacturea stiffened speaker diaphragm Bian and Zhao reported thatYoungrsquos moduli of CNTs decrease when the temperatureof the environment exceeds 200∘C [10] In our study theproposed TTP stiffening technique does not require a highcuring temperature that decreases the mechanical propertyof CNTs and the TTP technique can stiffen a localizedarea on a diaphragm substrate thus increasing diaphragmstiffness without markedly raising diaphragm weight hencethe inherent strength of CNTs was preserved The resultingCNT-based diaphragm exhibited increased stiffness whichimproved the bandwidth and sound quality of the speakerthereby markedly improving the overall smoothness of thesound curve Simultaneously the weight was reduced andthe adhesion was also improved while using the CNT-based diaphragm Besides in this study the Taguchi qualityengineeringmethod [11 12]was used tominimize the numberof experimental trials The paper is relationship amongthe manufacturing parameters including stiffening patterncoating direction transfer area and transfer temperatureof CNT-based diaphragm which have also been thereforeinvestigated

2 Analysis and Experimental Procedure

21 Analysis on ANSYS The finite element method (FEM)is used in this study by the assistance of ANSYS PLANE-42 element (Figure 1) PLANE-42 element is used for 2Dmodeling for solid structures [13] The element can be usedeither as a plane element or as an axisymmetric element Theelement has plasticity creep swelling stress stiffening largedeflection and large strain capabilities The following stepsare used to construct our model

Element coordinatesystem (shown forKEYOPT(1) = 1)

K

J

L

I x

y

2

3

1

4

Figure 1 PLANE-42 element of ANSYS [13]

Step 1 Build the solid structure and the finite element model

Step 2 Apply loads and obtain the solution

Step 3 Review the stresses

Step 4 Perform a design for optimization analysis

Eventually PLANE-42 element is applying the 2D mod-ule to approximate the 3D module It can effectively reducethe computation time and accurately analyze the stress valuesThe element is defined by four nodes having two degrees offreedom at each node and is translated in the nodal x and ydirections We can use these data to compute the shift stressand angles

This study assumes that the stress is maximized along119909-axis First the element type and the property of materialare defined to establish the finite element model Secondthe necessary boundary conditions are given and the stressesare resolved Third 120590

119909is maximized for the nodes which

are generated along the interface of the metallic material(base) and the coating material (coating) Finally the studyused ANSYS to analyzed the stress results for CNT-baseddiaphragm

22 Fabrication of TTP Paper and CNT-Based Diaphragm Inthis study a PEN membrane was used as the substrate forfabricating TTP paper The front and back of the PEN wererespectively coated with CNTepoxy and HMA to form theTTP paper The fabricated TTP paper was then thermallytransferred and printed onto a coarse paper to form adiaphragm Subsequently the effect of diaphragm fabricationon sound pressure curve smoothness was investigated andTaguchi quality engineering method was applied to identifythe optimal manufacturing parameters

A PEN membrane was used as the substrate for fabri-cating TTP paper We first mixed 2sim3wt CNTs (CF182CAdvanced Nanopower Inc) and epoxy (P859-1 Hong GuanRampD Co) as the CNTsepoxy composite paste In fact theCNTs with a density of 13sim14 gcm3 (similar to the cotton)are very fluffy and its volume is quite large Although wehave also mixed 4sim5wt CNTs and epoxy the experimentresult indicates that it requires a much longer mixing timeand the mixture has a high viscosity This would lead to a

Journal of Nanomaterials 3

CNTsepoxy

PEN

HMA

(a)

CNTsepoxy

PEN

HMA

Coarse paper

Locate Hot press Complete

Pressure

CNTsepoxy

PEN

HMA

Coarse paper

CNTsepoxy

PEN

HMA

Coarse paper

(b)

Figure 2 Schematic CNT-based diagram of the (a) TTP paper and (b) TTP processes

nonuniform surface of the TTP paper As shown in Figure the TTP paper was fabricated by coating the front side of aPEN membrane with CNTsepoxy paste and then drying itin an oven at 120∘C for 15min After the CNTsepoxy coatinglayer was dried the backside of PEN was coated with HMAand was dried again in the oven at 80∘C for 10min to obtaina TTP paper The CNTsepoxy coating was used to adjust thethickness of TTP paper in addition manually roller-pressingthe CNTsepoxy coating onto the TTP paper enabled evenlyspreading the coating onto the material surface

After the fabrication of TTP paper a TTP process wasused to thermally transfer and print the TTP paper ontocoarse paper to form a CNT-based diaphragm at an elevatedtemperature In this study as shown in Figure the resultingTTP paper was first stacked onto the coarse paper diaphragmand then subjected to a TTP process in a TTP machineThe following steps of TTP process were illustrated inFigure After pressing to 02 kgcm2 and heating at 80sim120∘C for 10min the fabrication of CNT-based diaphragmwas complete This study also adopted cold cathode fieldemission scanning electronmicroscope (FE-SEM JEOL JSM-740F Japan) to observe the cross sections of the CNT-baseddiaphragm

23 Material Properties for Test Specimens To obtain theproperties and strengths of the coarse paper TTP paperand CNT-based diaphragm three types of tensile specimengeometry will be employed The test specimen dimensionsare 125mm times 100mm The material properties of laminated

composite face sheets and foam core where determinedfrom experiments conducted in accordance with the rele-vant ASTM (D3039-79 and D3518-76) standards [14] Thespecimens should be mounted and tested in a properlyaligned and calibrated INSTRON-1332 test machine Wedgeaction friction grips of hydraulic grips will be used Set thecrosshead rate at about 10mmmin The strains and loadreadings may be recorded continuously or at discrete loadintervals If the discrete data are taken a sufficient numberof data points must be recorded in order to reproduce thestress-strain relation At least 25 data points are needed inthe linear response region Monitor all specimens to failureand then determine the ultimate strengths and strains Plotthe data for reduction Establish the Youngrsquos modulus andPoissonrsquos ratio by a least square fit of the linear region Forfinding the mechanical properties and ultimate strengths(strains) some specimens are tested statically to failureThe stress-strain response of tensile coupon is monitoredwith electrical resistance strain gauge in order to find theintrinsic mechanical properties of the coarse paper TTPpaper and CNT-based diaphragmThematerial properties tobe measured include (i) Youngrsquos modulus (ii) Poissonrsquos ratio(iii) ultimate tensile stress (failure strength)

24 Panel Speaker Assembly Figure 3(a) shows the Solid-Works explosion diagram of the panel speaker After variousspeaker components were prepared and ready for assemblythe fabricated CNT-based diaphragm was adhered to thespeaker surround which was then assembled to the upperframe as shown in Figure 3(b) The surround material


Under theExciterWasher

FramePowerful magnet

Magnet frame

Surround

Diaphragm

framework

(a)

(b)

Figure 3 (a) SolidWorks explosion diagram of the thin panelspeaker (b) thin panel speaker assembly processes

selected for our panel speaker was polyurethane (PU) withthe actual specification which is 30 times 20 times 10mm PU wasplaced into a surround mold and heat pressed in an ovento form the speaker surround which was then attached tothe diaphragm and voice coil Subsequently the vibrationexciter (voice coil) was attached at 90∘ perpendiculars to thediaphragm A shown in Figures 3(a) and 3(b) the exciterwas placed between the magnet and the magnet frame Themagnets were placed above the washer to increase the mag-netic flux The speaker gives sound through the diaphragmvibration that pushed by the voice coil Most importantlythe vibration exciter (voice coil) must be attached to thecentral area of the diaphragm Otherwise sound distortion iseasily incurred Once all the steps have been completed theadhesives were allowed to solidify for a day after which thesound pressure curve of the speaker can be measured

25 Sound Pressure Curve Measurement and Analysis Toavoid influencing the measurement results sound pressurecurve must be measured in an anechoic chamber insulatedfrom external sources of noise acoustical measurement sys-tem and CLIO software analysis were employed inmeasuringthe sound pressure curve In the CLIO software the numberof points bandwidth and voltagewere definedThemeasuredbandwidth was 20Hzsim20 kHz audible to the human earand was measured at a distance of 10 cm from the self-developed panel speaker Subsequently after the input voltageof the speaker was configured the sound pressure curve anddata were measured In the sound pressure curve the valuedifference (ΔdB) between curve valley and sound pressurelevel (SPL) at 12sim18 kHz high frequency dip difference value(ΔdB) was used to identify the quality of the sound Aminimum high frequency dip difference value (ΔdB) gives asmooth sound pressure curve in the high frequency regionand a better sound quality

26 Taguchi Quality Engineering Because stiffening theentire diaphragm may influence the overall sensitivity ofthe speaker we attempted to circumvent this problem byperforming optimization analysis using the Taguchi methodThrough the Taguchi approach the optimal product designobjective or process can be determined to facilitatemitigatingthe effects of confounding factors [11 12] This study investi-gated the relationship among the manufacturing parametersof CNT-based diaphragm (stiffening pattern coating layerstransfer area and heat press temperature) and the Taguchiequations representing the smaller-the-better (see (1)) char-acteristics are shown as follows

SN = minus10 log10

sum119899

119896=1

1198842

119894

119899 (1)

The selected manufacturing parameters of CNT-baseddiaphragm were aimed at having a minimum high frequencydip difference value (ΔdB) in the sound pressure curve of aspeaker subsequently smoothing the sound pressure curvein the high frequency region Figures 4 and 5 present theparameters obtained from the Taguchi method Figures 4(a)and 4(b) show the top and side view of the transfer area of theTTP paper on coarse paper respectively Figure 5 illustratesthe stiffening patterns on the TTP paper and the coatingdirection of 1 or 2 coating layers Furthermore the analysisof variance (ANOVA) was also used to find the dominantinfluence factors

3 Results and Discussion

31 Comparison of ANSYS and Related Papers for NumericalExample The manufacturing parameters of coating materi-als on a flat plate are the thickness of coating and the order ofplates We compared our ANSYS results with other similarresearches After that we actually used the ANSYS modelfor simulationThe material properties of metals and coatingmaterials are shown Table 1

Shaw [2] indicated that the influencing factors of ouranalysis are the composition gradient the elastic modulenumber of layers thermal expansion coefficients and soforth Shaw used functionally graded materials (FGM) andmultilayer composite material on thermal coating and ana-lyzed the thermal residual stress Since our study was similarto Shawrsquos results we compared three materials of metal andceramic with Shawrsquos results in Table 2

Furthermore Ozel et al [3] coated the advanced ceramicon the metallic plate and minimized the stress as his goalWe also use the stress objective proposed by Ozel et al asour programming goal in this study And different coatingmaterials Si

3N4 Al2O3 and TiC are coated on the W metal

plate by ANSYS methods so as to compare the thermalstresses with Ozel et alrsquos results in Table 3 The fluctuationbetween the analytic results from ANSYS method and pub-lished practical results fluctuated from 142 to 766 witha summarized average 431 Therefore the paper used theANSYS method into coarse paper and TTP paper interfaceshear stress problem Finally we compare our ANSYS model


Table 1 Material properties of metals and coating materials

Materials

Properties

Youngrsquos modulus 119864(GPa) Poissonrsquos ratio ] Thermal conductivity 119870

(Wm∘C)

Coefficient of thermalexpansion (CTE) 120572

(1∘C)Al 70 033 34 23 times 10minus5

W 410 028 29 45 times 10minus6

Diamond 1050 020 2 175 times 10minus6

Si3

N4

230 026 28 35 times 10minus6

Al2

O3

340 023 24 81 times 10minus6

TiC 340 019 27 71 times 10minus6

NiAl 103 017 53 146 times 10minus6

Coarse paper

TTP paper

Coarse paper

TTP paper TTP paper

12 transfer area 34 transfer area 11 transfer area

(a)

12 transfer area

34 transfer area

11 transfer area

Coarse paper

CNTsepoxyand PENHMA

(b)

Figure 4 (a) Top view of three types of transfer area (b) side viewof three types of transfer area

1 2 1 2 1 1

2

2

1 2

21

Unidirectional 90∘ cross 45∘ angle

Figure 5 Three types of stiffening patterns of the TTP paperNumbers present the coating direction of patterns containing 1 or2 coating layers

Table 2 Comparison of Shawrsquos results and ANSYS

Materialproperties

Shaw [2]120590119909

(119888119892

)

ANSYSmethod120590119909

(119888119889

)

Differential|(119888119892

minus 119888119889

)119888119892

| times 100

I (MPa) 1745 19513 1182II (MPa) 1715 17491 198III (MPa) 9965 9144 823

Table 3 Compare the stressesrsquo decrease progressively with Ozel etalrsquos results and ANSYS method

Materialproperties

Ozel et al[3]120590119909

(119888119892

)


(119888119889

)


minus 119888119889

)119888119892

| times 100

W + Si3

N4

minus92 minus9556 386W + Al

2

O3

minus136 minus12558 766W + TiC minus121 minus11927 142

Table 4 Comparing results with Han and Sunrsquos study and ANSYS

StressMethods

Han andSun [15]120590119909

(119888119892

)


(119888119889

)


minus 119888119889

)119888119892

| times 100

120590119909

(MPa) 37 4168 1264

with Han and Sunrsquos study in Table 4 Han and Sun [15] usedthe glass and alumni as his test base

According to the aforementioned comparisons we cansay that our ANSYS model is adequate to approximate theactual thermal coating process We also believe that theANSYS model is able to simulate the actual behavior of TTPtechnology

32 ANSYS Analyzed the Stress Results for CNT-BasedDiaphragm The specimens are used by INSTRON-1332 testmachine to obtain Youngrsquos modulus and strengths of thecoarse paper TTP paper and CNT-based diaphragm whichare shown in Table 5 The study compared CNT-based


Table 5 Properties of coarse paper TTP paper and CNT-based diaphragm

MaterialsProperties

Thicknesses (mm) Youngrsquos modulus 119864(GPa)

Failure Strength(MPa) Poissonrsquos ratio ] CTE 120572 (1∘C)

Coarse paper (119862119892

) 0210 214 3251 028 23 times 10minus6

TTP Paper 0027 271 4882 033 251 times 10minus6

CNT-based diaphragm(119862119889

) 0237 258 4512 031 mdash


minus 119888119889

)119888119892

| times 100 mdash 2056 2648 mdash mdash

Table 6 Mechanical properties of CNT-based diaphragm withdifferent TTP curing temperature

Temperature

Properties

Thicknesses(mm)

Youngrsquosmodulus 119864(GPa)

Failure strength(MPa)

100∘C 0245 223 3551120∘C 0237 258 4112130∘C 0237 259 4108140∘C 0237 257 4110

Table 7 Mechanical properties of TTP papers with different CNTswt

Wt

Properties

Thicknesses(mm)



3wt 0027 271 48825wt 0032 268 4875

diaphragm with coarse paper mechanical properties whichis increased 2056 with Youngrsquos modulus results in Table 5This study developed a TTP technique to fabricate a CNTsstiffened coarse paper which could be manufactured speakerdiaphragm

The thermosetting resins with a curing temperature of120∘Cwere used in this study After curing at 120∘C a networkstructure was formed in the resin by intermolecular cross-linking Moreover the resin was not softened even thoughthe reheating treatment was performed Therefore self-developed TTP stiffening technique does not require highcuring temperature The experiment results on mechanicalproperties of CNT-based diaphragm with different TTP cur-ing temperature are shown in Table 6 It reveals that the CNT-based diaphragm with the 120∘C curing temperature hasgood mechanical properties Additionally the mechanicalproperties of TTP papers with different CNTs wt (3wtand 5wt) are summarized in Table 7 It is obvious that thesetwo TTP papers have almost the samemechanical propertiesTherefore we used 3wt CNTepoxy coating onto the TTPpapers which could reduce the cost and has the uniformcoating surface

TTPpaper

Coarsepaper0

24m

m

30mmX

Y

Z

Max 120590xy

Figure 6 Module of finite element method (FEM) with structure ofCNT-based diaphragm

We also believe that the ANSYS model (see Figure 6) isable to simulate the actual behavior of CNT-based diaphragm(modelrsquos dimension is 30 times 024mm) with TTP temperatureat 80∘C and our simulated results are available in Table 8The study compared shear stress result with coarse paperand TTP failure strength the shear stress is less than 1666sim2998 of the breaking strength of the coarse paper andTTP material which is safe in transfer interface This studyused the numerical analysis software (ANSYS) to analyzedthe stress and thermal of work piece which have not beendelaminated problems in transfer interface The materialswith the higher failure strength could allow the shear stressat high temperatures which did not produce the peelingproblem in the transfer interface

33Microscopic Structure of CNT-BasedDiaphragm Figure 7presents the sectional images of the CNT-based diaphragmFor a conventional speaker diaphragm fabrication a PENpasted on the coarse paper directly By using the TTP processas shown in Figures 7(a) and 7(b) the hot melt layer diffusesinto the coarse paper and gives an enhanced adhesionFigure 7(b) shows the enlarged photo of Figure 7(a) On theimages arrows represent the material structure in variousregions of the diaphragm It was observed that CNTsepoxycoating was evenly applied onto the diaphragm The coatedcoarse paper presented more grooves and deeper groovesof uneven depth than the coated PEN paper did primarilybecause the coarse paper contained a mixture of fibers Inaddition the FE-SEM images revealed that the CNTsepoxycoatings on the coarse paper and PEN side of the paper wereevenly distributed on the coating material indicating thatthe coating was evenly and favorably dispersedThe sectionalFE-SEM images show that the TTP paper is tightly boundto the coarse paper substrate exhibiting an even thicknessapproximating 2695 120583m


Table 8 Comparing results with ANSYS method and material failure strength

Shear stressMethods

ANSYSanalysis result (119862

119860

)Coarse paper failure

strength (119862119888

)TTP paper failurestrength (119862

119879

)Differential

1003816100381610038161003816(119888119862 minus 119888119860) 1198881198601003816100381610038161003816 times 100

Differential1003816100381610038161003816(119888119879 minus 119888119860) 119888119860

1003816100381610038161003816 times 100120590119909119910

(MPa) 122 3251 4882 1663 2998

Coarse paper

TTP paper

CNT-based diaphragm

(a)

Coarse paper

TTP paper

Coarse paper + HMA

(b)

Figure 7 FE-SEMsectional images of (a) the self-developed speakerdiaphragm (b) is the enlarged photo of (a)

34 Taguchi Quality Engineering OptimalHigh FrequencyDipDifference Value (ΔdB) This high frequency dip differencevalue primarily influences the smoothness and bandwidthof the curve a small valley difference indicates large soundrange which increases the clarity of the speakerrsquos midfre-quency and high frequency sounds Therefore the minimalhigh frequency dip difference value is desirable As shownin Table 9 the Taguchi quality engineering method wasused to minimize the number of experimental trials andthe applicable orthogonal array was selected according to the

Table 9 Taguchi-selected factors

Factors Level1 2 3

119860 Transfer area 12 34 11119861 Stiffening pattern Unidirectional 90∘ cross 45∘ angle119862 Coating layers No 1 layer 2 layers119863 Transfer temperature 80∘C 100∘C 120∘C

minus4000

minus3800

minus3600

minus3400

minus3200

minus3000

minus2800

minus2600

A1 A2 A3 B1 B2 B3 C1 C2 C3 D1 D3D2

Transfer areaStiffening pattern

Coating layersTransfer temperature (∘C)

Figure 8 Main effect diagram of the high frequency dip difference(ΔdB)

controllable factors and level numbers To obtain a minimaldifference value the smaller-the-better characteristic wasused to determine the optimal manufacturing parameters aslisted in Table 10

Table 11 presents the cause and effect table showing theranking of each experimental factor according to its level ofcontribution As shown in Figure 8 the main effect diagramreveals that a factor with a steep slope critically influences theoverall experimental results The crucial factors influencingthe high frequency dip difference in the sound pressurecurve in order from highest to lowest level of contributionwere transfer area coating layers transfer temperature andstiffening pattern By using the ANOVA analysis significantmanufacturing parameters can be easily obtained in thisstudy The criteria of significant manufacturing parametersare cumulating the contribution ratio to 998 The ANOVAanalysis for high frequency dip difference was listed inTable 12 and was plotted as in Figure 9 Specifically thetransfer area has the greatest influence (685) followed bythe coating layers (255) transfer temperature (47) andstiffening pattern (11) As a result to obtain the minimalhigh frequency dip difference value transfer area and coatinglayers are the dominant parameters with contribution at 685and 255 respectively


Table 10 Smaller-the-better L9

orthogonal array

Number Factors ΔdB values SN119860 119861 119862 119863 119884

1

1198842

1198843

1 12 Unidirectional No 80 262 267 266 minus846522 12 90∘ cross 1 layer 100 319 315 311 minus996673 12 45∘ angle 2 layers 120 259 25 262 minus820044 34 Unidirectional 1 layer 120 439 442 451 minus129485 34 90∘ cross 2 layers 80 321 319 314 minus1004896 34 45∘ angle No 100 361 366 362 minus1119837 11 Unidirectional 2 layers 100 356 353 359 minus1102928 11 90∘ cross No 120 431 437 428 minus1271009 11 45∘ angle 1 layer 80 427 426 429 minus126154

Table 11 Cause and effect table of the high frequency dip difference(ΔdB)

Level Factors119860 119861 119862 119863

Level 1 minus266323 minus324426 minus323735 minus316555Level 2 minus341954 minus327256 minus360563 minus321942Level 3 minus368806 minus320140 minus292785 minus338586Influencequantity 102483 02829 67778 22031

Ranking 1 4 2 3

Table 12 Degree of influence of each factor in terms of percentagesfor the high frequency dip difference (ΔdB)

Factors 119878119896

119881Influencepercentage

Progressivepercentage

119860 Transfer area 188267 94133 685 685119862 Coating layers 76756 38378 255 940

119863Transfer

temperature 08794 04397 47 987

119861Stiffeningpattern 00138 00069 11 998

As the optimal manufacturing parameters are notincluded in the L

9orthogonal array the optimal manufactur-

ing parameters to attain a stiffened speaker diaphragm withminimal high frequency dip difference value was determinedby selecting the maximum points from the main effectdiagram of Figure 8 As a result the optimal parameter com-bination obtained using the Taguchi method was 12 transferarea 45∘ angle ply stiffening pattern 2 coating layers and80∘C HMA transfer temperature The 45∘ angle ply stiffeningpattern has the highest coating area on the PEN surface andleads to a better stiffness Furthermore only half area of thediaphragm was coated with CNTsepoxy composite and theweight of the diaphragmwas significantly reducedThereforea CNT-based diaphragm was fabricated using the optimalparameter and named as number 10 Figure 10 compares thesound pressures curve of the speakers produced using two

001002003004005006007008009001000

000100020003000400050006000700080009000

10000

Influence percentageProgressive percentage

Transfertemperature

(∘C)

Coatinglayers

Transferarea

Stiffeningpattern

()

()

Figure 9 Pareto chart of the high frequency dip difference (ΔdB)

different CNT-based diaphragms number 3 and number 10The number 3 CNT-based diaphragm exhibits the smallesthigh frequency dip difference value of the sound pressurecurve among the nine diaphragms fabricated form Table 10The black and red dashed lines and arrows in Figure 10indicate the high frequency dip difference of number 3 andnumber 10 diaphragms respectively The number 10 CNT-based diaphragm produced a high frequency dip differ-ence (098 dB) smaller than that of number 3 diaphragm(256 dB) improving the high frequency dip difference by6172 Except high frequency region number 10 CNT-based diaphragm shows a smaller dip difference at highfrequency As shown in Figure 10 the blue dashed line andarrow indicates the dip difference of number 10 CNT-baseddiaphragm As a result at high frequency region number 10CNT-based diaphragm shows a small dip difference and adelayed peak frequency as compared to number 3CNT-baseddiaphragm

Actually the medium-low frequency and high frequencyof voices could be both controlled by Youngrsquos modulusand stiffness of CNT-based diaphragms and then showthe powerful voices For panel speakers the CNT-baseddiaphragms with a high stiffness would result in clear andsmooth sound pressure curve at the 20Hzsim20 kHz Howeverthe sound properties including the sound pressure curve andthe frequency range could be not affected by the strength andthe shear stress properties of CNT-based diaphragms


100 1000 100000

20

40

60

80

100

120

SPL

(dB)

Number 10Number 3

Number of groupsNumber 10 (optimal speaker)Number 3

098256

High frequency dip difference (ΔdB)Comparison of the high frequency dip difference (ΔdB) values

Frequency (Hz)

256dB

Figure 10 Comparison of high frequency dip difference values ofthe sound pressure curves

4 Conclusion

This study uses laminate plate theory to analyze the thermaltransfer printing technology by the assistance of ANSYSTheanalytic results fromANSYSmethod are found to be superiorto results from other studies showing that the proposedhypothesis is valuable The TTP paper is manufacturingCNT-based diaphragm which has not been delaminatedproblem in transfer interface for the analytic results fromANSYS method

Following various experiments and measurementssound pressure curves were analyzed using the Taguchimethod to determine the crucial manufacturing parametersfor a TTP technique The results verified that the CNT-baseddiaphragm fabricated using the proposed TTP methodimproved the sound pressure curve smoothness of a panelspeaker Moreover the Taguchi method was used to effec-tively identify the optimal manufacturing parameters and themost influential factors The empirical experiments conduct-ed in this study confirmed that the optimal manufacturingparameters can be used to obtain theminimal high frequencydip difference

According to the ANOVA analysis the significant con-tribution percentage for having the minimal high frequencydip difference was also investigated For the high frequencydip difference it was found the transfer area has the greatestinfluence (685) followed by the coating layers (255)transfer temperature (47) and stiffening pattern (11)

Using the Taguchi quality engineering method the opti-mal manufacturing parameters combination for achievingminimum high frequency dip difference composed of a 12transfer area 45∘ angle-shaped stiffening pattern 2 layers ofcoating and a transfer temperature of 80∘C It was observed

that the CNT-based diaphragm andTTP technique improvedthe smoothness of the sound pressure curve and the optimalmanufacturing parameters enabled fabricating a speakerthat produced a high frequency dip difference of 098 dB(improving the difference values by 6172)

Competing Interests

The authors declare that there are no competing interestsregarding the publication of this paper

Acknowledgments

The authors would like to thank the Ministry of Science andTechnology in Taiwan for financially support of this researchproject under Grant no 102-2221-E-212-006

References

[1] M N Ozisik Heat Conduction John Wiley amp Sons New YorkNY USA 1980

[2] L L Shaw ldquoThermal residual stresses in plates and coatingscomposed of multi-layered and functionally graded materialsrdquoComposites Part B Engineering vol 29 no 3 pp 199ndash210 1998

[3] A Ozel V Ucar AMimaroglu and I Calli ldquoComparison of thethermal stresses developed in diamond and advanced ceramiccoating systems under thermal loadingrdquoMaterials and Designvol 21 no 5 pp 437ndash440 2000

[4] F Gardea and D C Lagoudas ldquoCharacterization of electricaland thermal properties of carbon nanotubeepoxy compositesrdquoComposites Part B Engineering vol 56 pp 611ndash620 2014

[5] A Montazeri J Javadpour A Khavandi A Tcharkhtchi andA Mohajeri ldquoMechanical properties of multi-walled carbonnanotubeepoxy compositesrdquoMaterials and Design vol 31 no9 pp 4202ndash4208 2010

[6] S M Park and M Y Shon ldquoEffects of multi-walled carbonnano tubes on corrosion protection of zinc rich epoxy resincoatingrdquo Journal of Industrial and Engineering Chemistry vol21 pp 1258ndash1264 2015

[7] J M Wernik and S A Meguid ldquoOn the mechanical char-acterization of carbon nanotube reinforced epoxy adhesivesrdquoMaterials and Design vol 59 pp 19ndash32 2014

[8] M M Shokrieh A Daneshvar and S Akbari ldquoReduction ofthermal residual stresses of laminated polymer composites byaddition of carbon nanotubesrdquoMaterials andDesign vol 53 pp209ndash216 2014

[9] F M Lai ldquoUsing ant colony optimization for process variablesof thermal transfer printing technologyrdquo in Proceedings of theAsian-Pacific Conference on Aerospace Technology and Sciencevol 6 pp 219ndash227 2013

[10] L Bian and H Zhao ldquoElastic properties of a single-walledcarbon nanotube under a thermal environmentrdquo CompositeStructures vol 121 pp 337ndash343 2015

[11] K Z K Ahmad S H Ahmad M A Tarawneh and P R ApteldquoEvaluation of mechanical properties of epoxynanoclaymulti-walled carbon nanotube nanocomposites using taguchimethodrdquo Procedia Chemistry vol 4 pp 80ndash86 2012

[12] RAzadi andY Rostamiyan ldquoExperimental and analytical studyof buckling strength of new quaternary hybrid nanocomposite


using Taguchi method for optimizationrdquo Construction andBuilding Materials vol 88 pp 212ndash224 2015

[13] ANSYSMechanical APDLModeling andMeshing Guide ANSYSInc 2011

[14] ASTM Astm Standards and Literature References for CompositeMaterials Astm International West Conshohocken Pa USA2nd edition 1990

[15] C Han and C T Sun ldquoA study of pre-stress effect on staticand dynamic contact failure of brittle materialsrdquo InternationalJournal of Impact Engineering vol 24 no 6-7 pp 597ndash611 2000

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of



CeramicsJournal of


CompositesJournal of

NanoparticlesJournal of



International Journal of

Biomaterials


NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of


The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014


CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research



MetallurgyJournal of


BioMed Research International

MaterialsJournal of


Nano

materials


Journal ofNanomaterials


poor adhesion and overweight problem occur and limit theirapplication It is reported that using CNTs as an additive canenhance the mechanical property of resin [4ndash6] Comparedwith regular polymer CNTs have lower expansion coefficientwhich reduces the residual stress in laminated polymercomposites In addition CNTs have favorable strength andstiffness and are capable of changing material propertiessuch as electrical and thermal conductivity However paststudies also have observed that mixing high-concentrationCNTs with epoxy lowers the mechanical strength of theepoxy which is primarily attributable to the aggregation ofthe CNTs and the formation of hollow pores in the epoxy[7 8] Regardless the composite coating containing CNTsand epoxy has not been studied for using as the diaphragmin thin panel speaker

In this study we self-developed a TTP technique toprepare the diaphragm in thin panel speaker TTP is a man-ufacture through which coatings are bonded to the surfaceof a transfer material at temperature from 80∘C to 120∘C[9] The composite paste of CNTs and epoxy was first roller-pressed onto a polyethylene naphthalate (PEN) substrate toreinforce the PEN after which the backside of the PEN wascoated with hot melt adhesive (HMA) The fabricated TTPpaper (CNTs+epoxyPENHMA) was cut into adequate sizeand shape Next a TTP machine was used to locally orfully press TTP paper onto a coarse paper to manufacturea stiffened speaker diaphragm Bian and Zhao reported thatYoungrsquos moduli of CNTs decrease when the temperatureof the environment exceeds 200∘C [10] In our study theproposed TTP stiffening technique does not require a highcuring temperature that decreases the mechanical propertyof CNTs and the TTP technique can stiffen a localizedarea on a diaphragm substrate thus increasing diaphragmstiffness without markedly raising diaphragm weight hencethe inherent strength of CNTs was preserved The resultingCNT-based diaphragm exhibited increased stiffness whichimproved the bandwidth and sound quality of the speakerthereby markedly improving the overall smoothness of thesound curve Simultaneously the weight was reduced andthe adhesion was also improved while using the CNT-based diaphragm Besides in this study the Taguchi qualityengineeringmethod [11 12]was used tominimize the numberof experimental trials The paper is relationship amongthe manufacturing parameters including stiffening patterncoating direction transfer area and transfer temperatureof CNT-based diaphragm which have also been thereforeinvestigated

2 Analysis and Experimental Procedure

21 Analysis on ANSYS The finite element method (FEM)is used in this study by the assistance of ANSYS PLANE-42 element (Figure 1) PLANE-42 element is used for 2Dmodeling for solid structures [13] The element can be usedeither as a plane element or as an axisymmetric element Theelement has plasticity creep swelling stress stiffening largedeflection and large strain capabilities The following stepsare used to construct our model

Element coordinatesystem (shown forKEYOPT(1) = 1)

K

J

L

I x

y

2

3

1

4

Figure 1 PLANE-42 element of ANSYS [13]

Step 1 Build the solid structure and the finite element model

Step 2 Apply loads and obtain the solution

Step 3 Review the stresses

Step 4 Perform a design for optimization analysis

Eventually PLANE-42 element is applying the 2D mod-ule to approximate the 3D module It can effectively reducethe computation time and accurately analyze the stress valuesThe element is defined by four nodes having two degrees offreedom at each node and is translated in the nodal x and ydirections We can use these data to compute the shift stressand angles

This study assumes that the stress is maximized along119909-axis First the element type and the property of materialare defined to establish the finite element model Secondthe necessary boundary conditions are given and the stressesare resolved Third 120590

119909is maximized for the nodes which

are generated along the interface of the metallic material(base) and the coating material (coating) Finally the studyused ANSYS to analyzed the stress results for CNT-baseddiaphragm

22 Fabrication of TTP Paper and CNT-Based Diaphragm Inthis study a PEN membrane was used as the substrate forfabricating TTP paper The front and back of the PEN wererespectively coated with CNTepoxy and HMA to form theTTP paper The fabricated TTP paper was then thermallytransferred and printed onto a coarse paper to form adiaphragm Subsequently the effect of diaphragm fabricationon sound pressure curve smoothness was investigated andTaguchi quality engineering method was applied to identifythe optimal manufacturing parameters

A PEN membrane was used as the substrate for fabri-cating TTP paper We first mixed 2sim3wt CNTs (CF182CAdvanced Nanopower Inc) and epoxy (P859-1 Hong GuanRampD Co) as the CNTsepoxy composite paste In fact theCNTs with a density of 13sim14 gcm3 (similar to the cotton)are very fluffy and its volume is quite large Although wehave also mixed 4sim5wt CNTs and epoxy the experimentresult indicates that it requires a much longer mixing timeand the mixture has a high viscosity This would lead to a


CNTsepoxy

PEN

HMA

(a)

CNTsepoxy

PEN

HMA

Coarse paper


Pressure

CNTsepoxy

PEN

HMA

Coarse paper

CNTsepoxy

PEN

HMA

Coarse paper

(b)










Magnet frame

Surround

Diaphragm

framework

(a)

(b)





SN = minus10 log10

sum119899

119896=1

1198842

119894

119899 (1)










Materials

Properties


(Wm∘C)


(1∘C)Al 70 033 34 23 times 10minus5

W 410 028 29 45 times 10minus6


Si3

N4

230 026 28 35 times 10minus6

Al2

O3

340 023 24 81 times 10minus6



Coarse paper

TTP paper

Coarse paper

TTP paper TTP paper


(a)

12 transfer area

34 transfer area

11 transfer area

Coarse paper

CNTsepoxyand PENHMA

(b)


1 2 1 2 1 1

2

2

1 2

21




Materialproperties

Shaw [2]120590119909

(119888119892

)


(119888119889

)


minus 119888119889

)119888119892

| times 100



Materialproperties

Ozel et al[3]120590119909

(119888119892

)


(119888119889

)


minus 119888119889

)119888119892

| times 100

W + Si3

N4


2

O3



StressMethods

Han andSun [15]120590119909

(119888119892

)


(119888119889

)


minus 119888119889

)119888119892

| times 100

120590119909

(MPa) 37 4168 1264






MaterialsProperties




) 0210 214 3251 028 23 times 10minus6



) 0237 258 4512 031 mdash


minus 119888119889

)119888119892



Temperature

Properties

Thicknesses(mm)



100∘C 0245 223 3551120∘C 0237 258 4112130∘C 0237 259 4108140∘C 0237 257 4110


Wt

Properties

Thicknesses(mm)



3wt 0027 271 48825wt 0032 268 4875



TTPpaper

Coarsepaper0

24m

m

30mmX

Y

Z

Max 120590xy






Shear stressMethods


119860


strength (119862119888


119879

)Differential

1003816100381610038161003816(119888119862 minus 119888119860) 1198881198601003816100381610038161003816 times 100


1003816100381610038161003816 times 100120590119909119910

(MPa) 122 3251 4882 1663 2998

Coarse paper

TTP paper

CNT-based diaphragm

(a)

Coarse paper

TTP paper

Coarse paper + HMA

(b)




Factors Level1 2 3


minus4000

minus3800

minus3600

minus3400

minus3200

minus3000

minus2800

minus2600

A1 A2 A3 B1 B2 B3 C1 C2 C3 D1 D3D2








orthogonal array


1

1198842

1198843



Level Factors119860 119861 119862 119863


Ranking 1 4 2 3


Factors 119878119896




119863Transfer

temperature 08794 04397 47 987





001002003004005006007008009001000

000100020003000400050006000700080009000

10000


Transfertemperature

(∘C)

Coatinglayers

Transferarea

Stiffeningpattern

()

()





100 1000 100000

20

40

60

80

100

120

SPL

(dB)

Number 10Number 3


098256


Frequency (Hz)

256dB


4 Conclusion






Competing Interests


Acknowledgments


References

























CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials




CNTsepoxy

PEN

HMA

(a)

CNTsepoxy

PEN

HMA

Coarse paper


Pressure

CNTsepoxy

PEN

HMA

Coarse paper

CNTsepoxy

PEN

HMA

Coarse paper

(b)










Magnet frame

Surround

Diaphragm

framework

(a)

(b)





SN = minus10 log10

sum119899

119896=1

1198842

119894

119899 (1)










Materials

Properties


(Wm∘C)


(1∘C)Al 70 033 34 23 times 10minus5

W 410 028 29 45 times 10minus6


Si3

N4

230 026 28 35 times 10minus6

Al2

O3

340 023 24 81 times 10minus6



Coarse paper

TTP paper

Coarse paper

TTP paper TTP paper


(a)

12 transfer area

34 transfer area

11 transfer area

Coarse paper

CNTsepoxyand PENHMA

(b)


1 2 1 2 1 1

2

2

1 2

21




Materialproperties

Shaw [2]120590119909

(119888119892

)


(119888119889

)


minus 119888119889

)119888119892

| times 100



Materialproperties

Ozel et al[3]120590119909

(119888119892

)


(119888119889

)


minus 119888119889

)119888119892

| times 100

W + Si3

N4


2

O3



StressMethods

Han andSun [15]120590119909

(119888119892

)


(119888119889

)


minus 119888119889

)119888119892

| times 100

120590119909

(MPa) 37 4168 1264






MaterialsProperties




) 0210 214 3251 028 23 times 10minus6



) 0237 258 4512 031 mdash


minus 119888119889

)119888119892



Temperature

Properties

Thicknesses(mm)



100∘C 0245 223 3551120∘C 0237 258 4112130∘C 0237 259 4108140∘C 0237 257 4110


Wt

Properties

Thicknesses(mm)



3wt 0027 271 48825wt 0032 268 4875



TTPpaper

Coarsepaper0

24m

m

30mmX

Y

Z

Max 120590xy






Shear stressMethods


119860


strength (119862119888


119879

)Differential

1003816100381610038161003816(119888119862 minus 119888119860) 1198881198601003816100381610038161003816 times 100


1003816100381610038161003816 times 100120590119909119910

(MPa) 122 3251 4882 1663 2998

Coarse paper

TTP paper

CNT-based diaphragm

(a)

Coarse paper

TTP paper

Coarse paper + HMA

(b)




Factors Level1 2 3


minus4000

minus3800

minus3600

minus3400

minus3200

minus3000

minus2800

minus2600

A1 A2 A3 B1 B2 B3 C1 C2 C3 D1 D3D2








orthogonal array


1

1198842

1198843



Level Factors119860 119861 119862 119863


Ranking 1 4 2 3


Factors 119878119896




119863Transfer

temperature 08794 04397 47 987





001002003004005006007008009001000

000100020003000400050006000700080009000

10000


Transfertemperature

(∘C)

Coatinglayers

Transferarea

Stiffeningpattern

()

()





100 1000 100000

20

40

60

80

100

120

SPL

(dB)

Number 10Number 3


098256


Frequency (Hz)

256dB


4 Conclusion






Competing Interests


Acknowledgments


References

























CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials






Magnet frame

Surround

Diaphragm

framework

(a)

(b)





SN = minus10 log10

sum119899

119896=1

1198842

119894

119899 (1)










Materials

Properties


(Wm∘C)


(1∘C)Al 70 033 34 23 times 10minus5

W 410 028 29 45 times 10minus6


Si3

N4

230 026 28 35 times 10minus6

Al2

O3

340 023 24 81 times 10minus6



Coarse paper

TTP paper

Coarse paper

TTP paper TTP paper


(a)

12 transfer area

34 transfer area

11 transfer area

Coarse paper

CNTsepoxyand PENHMA

(b)


1 2 1 2 1 1

2

2

1 2

21




Materialproperties

Shaw [2]120590119909

(119888119892

)


(119888119889

)


minus 119888119889

)119888119892

| times 100



Materialproperties

Ozel et al[3]120590119909

(119888119892

)


(119888119889

)


minus 119888119889

)119888119892

| times 100

W + Si3

N4


2

O3



StressMethods

Han andSun [15]120590119909

(119888119892

)


(119888119889

)


minus 119888119889

)119888119892

| times 100

120590119909

(MPa) 37 4168 1264






MaterialsProperties




) 0210 214 3251 028 23 times 10minus6



) 0237 258 4512 031 mdash


minus 119888119889

)119888119892



Temperature

Properties

Thicknesses(mm)



100∘C 0245 223 3551120∘C 0237 258 4112130∘C 0237 259 4108140∘C 0237 257 4110


Wt

Properties

Thicknesses(mm)



3wt 0027 271 48825wt 0032 268 4875



TTPpaper

Coarsepaper0

24m

m

30mmX

Y

Z

Max 120590xy






Shear stressMethods


119860


strength (119862119888


119879

)Differential

1003816100381610038161003816(119888119862 minus 119888119860) 1198881198601003816100381610038161003816 times 100


1003816100381610038161003816 times 100120590119909119910

(MPa) 122 3251 4882 1663 2998

Coarse paper

TTP paper

CNT-based diaphragm

(a)

Coarse paper

TTP paper

Coarse paper + HMA

(b)




Factors Level1 2 3


minus4000

minus3800

minus3600

minus3400

minus3200

minus3000

minus2800

minus2600

A1 A2 A3 B1 B2 B3 C1 C2 C3 D1 D3D2








orthogonal array


1

1198842

1198843



Level Factors119860 119861 119862 119863


Ranking 1 4 2 3


Factors 119878119896




119863Transfer

temperature 08794 04397 47 987





001002003004005006007008009001000

000100020003000400050006000700080009000

10000


Transfertemperature

(∘C)

Coatinglayers

Transferarea

Stiffeningpattern

()

()





100 1000 100000

20

40

60

80

100

120

SPL

(dB)

Number 10Number 3


098256


Frequency (Hz)

256dB


4 Conclusion






Competing Interests


Acknowledgments


References

























CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials





Materials

Properties


(Wm∘C)


(1∘C)Al 70 033 34 23 times 10minus5

W 410 028 29 45 times 10minus6


Si3

N4

230 026 28 35 times 10minus6

Al2

O3

340 023 24 81 times 10minus6



Coarse paper

TTP paper

Coarse paper

TTP paper TTP paper


(a)

12 transfer area

34 transfer area

11 transfer area

Coarse paper

CNTsepoxyand PENHMA

(b)


1 2 1 2 1 1

2

2

1 2

21




Materialproperties

Shaw [2]120590119909

(119888119892

)


(119888119889

)


minus 119888119889

)119888119892

| times 100



Materialproperties

Ozel et al[3]120590119909

(119888119892

)


(119888119889

)


minus 119888119889

)119888119892

| times 100

W + Si3

N4


2

O3



StressMethods

Han andSun [15]120590119909

(119888119892

)


(119888119889

)


minus 119888119889

)119888119892

| times 100

120590119909

(MPa) 37 4168 1264






MaterialsProperties




) 0210 214 3251 028 23 times 10minus6



) 0237 258 4512 031 mdash


minus 119888119889

)119888119892



Temperature

Properties

Thicknesses(mm)



100∘C 0245 223 3551120∘C 0237 258 4112130∘C 0237 259 4108140∘C 0237 257 4110


Wt

Properties

Thicknesses(mm)



3wt 0027 271 48825wt 0032 268 4875



TTPpaper

Coarsepaper0

24m

m

30mmX

Y

Z

Max 120590xy






Shear stressMethods


119860


strength (119862119888


119879

)Differential

1003816100381610038161003816(119888119862 minus 119888119860) 1198881198601003816100381610038161003816 times 100


1003816100381610038161003816 times 100120590119909119910

(MPa) 122 3251 4882 1663 2998

Coarse paper

TTP paper

CNT-based diaphragm

(a)

Coarse paper

TTP paper

Coarse paper + HMA

(b)




Factors Level1 2 3


minus4000

minus3800

minus3600

minus3400

minus3200

minus3000

minus2800

minus2600

A1 A2 A3 B1 B2 B3 C1 C2 C3 D1 D3D2








orthogonal array


1

1198842

1198843



Level Factors119860 119861 119862 119863


Ranking 1 4 2 3


Factors 119878119896




119863Transfer

temperature 08794 04397 47 987





001002003004005006007008009001000

000100020003000400050006000700080009000

10000


Transfertemperature

(∘C)

Coatinglayers

Transferarea

Stiffeningpattern

()

()





100 1000 100000

20

40

60

80

100

120

SPL

(dB)

Number 10Number 3


098256


Frequency (Hz)

256dB


4 Conclusion






Competing Interests


Acknowledgments


References

























CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials





MaterialsProperties




) 0210 214 3251 028 23 times 10minus6



) 0237 258 4512 031 mdash


minus 119888119889

)119888119892



Temperature

Properties

Thicknesses(mm)



100∘C 0245 223 3551120∘C 0237 258 4112130∘C 0237 259 4108140∘C 0237 257 4110


Wt

Properties

Thicknesses(mm)



3wt 0027 271 48825wt 0032 268 4875



TTPpaper

Coarsepaper0

24m

m

30mmX

Y

Z

Max 120590xy






Shear stressMethods


119860


strength (119862119888


119879

)Differential

1003816100381610038161003816(119888119862 minus 119888119860) 1198881198601003816100381610038161003816 times 100


1003816100381610038161003816 times 100120590119909119910

(MPa) 122 3251 4882 1663 2998

Coarse paper

TTP paper

CNT-based diaphragm

(a)

Coarse paper

TTP paper

Coarse paper + HMA

(b)




Factors Level1 2 3


minus4000

minus3800

minus3600

minus3400

minus3200

minus3000

minus2800

minus2600

A1 A2 A3 B1 B2 B3 C1 C2 C3 D1 D3D2








orthogonal array


1

1198842

1198843



Level Factors119860 119861 119862 119863


Ranking 1 4 2 3


Factors 119878119896




119863Transfer

temperature 08794 04397 47 987





001002003004005006007008009001000

000100020003000400050006000700080009000

10000


Transfertemperature

(∘C)

Coatinglayers

Transferarea

Stiffeningpattern

()

()





100 1000 100000

20

40

60

80

100

120

SPL

(dB)

Number 10Number 3


098256


Frequency (Hz)

256dB


4 Conclusion






Competing Interests


Acknowledgments


References

























CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials





Shear stressMethods


119860


strength (119862119888


119879

)Differential

1003816100381610038161003816(119888119862 minus 119888119860) 1198881198601003816100381610038161003816 times 100


1003816100381610038161003816 times 100120590119909119910

(MPa) 122 3251 4882 1663 2998

Coarse paper

TTP paper

CNT-based diaphragm

(a)

Coarse paper

TTP paper

Coarse paper + HMA

(b)




Factors Level1 2 3


minus4000

minus3800

minus3600

minus3400

minus3200

minus3000

minus2800

minus2600

A1 A2 A3 B1 B2 B3 C1 C2 C3 D1 D3D2








orthogonal array


1

1198842

1198843



Level Factors119860 119861 119862 119863


Ranking 1 4 2 3


Factors 119878119896




119863Transfer

temperature 08794 04397 47 987





001002003004005006007008009001000

000100020003000400050006000700080009000

10000


Transfertemperature

(∘C)

Coatinglayers

Transferarea

Stiffeningpattern

()

()





100 1000 100000

20

40

60

80

100

120

SPL

(dB)

Number 10Number 3


098256


Frequency (Hz)

256dB


4 Conclusion






Competing Interests


Acknowledgments


References

























CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials





orthogonal array


1

1198842

1198843



Level Factors119860 119861 119862 119863


Ranking 1 4 2 3


Factors 119878119896




119863Transfer

temperature 08794 04397 47 987





001002003004005006007008009001000

000100020003000400050006000700080009000

10000


Transfertemperature

(∘C)

Coatinglayers

Transferarea

Stiffeningpattern

()

()





100 1000 100000

20

40

60

80

100

120

SPL

(dB)

Number 10Number 3


098256


Frequency (Hz)

256dB


4 Conclusion






Competing Interests


Acknowledgments


References

























CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials




100 1000 100000

20

40

60

80

100

120

SPL

(dB)

Number 10Number 3


098256


Frequency (Hz)

256dB


4 Conclusion






Competing Interests


Acknowledgments


References

























CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials















CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials



research article thermal stresses analysis and ... - hindawi

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