COMPARATIVE ANALYSIS OF TRACTOR'S TROLLEY … · the industry uses heavy axle without considering...

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Int. J. Mech. Eng. & Rob. Res. 2013 Manish S Lande and Sunil J Rajpal, 2013

COMPARATIVE ANALYSIS OF TRACTOR'STROLLEY AXLE BY USING FEA. (BY

CONSIDERING CHANGE IN MATERIALSEXISTING SHAPE AND SIZE)

Manish S Lande1* and Sunil J Rajpal1

*Corresponding Author: Manish S Lande, [email protected]

In Central India, various small scale industries are adopting the crude methodologies fordesigning and manufacturing the machine components. One such industry producing tractortrolleys for agricultural use has been identified for this study. The existing trolley designed bythe industry uses heavy axle without considering static and dynamic loading conditions whichin turn leads to higher factor of safety increasing the overall cost of the axle. In this study,existing trolley axle is comparatively analysed by considering the static and dynamic loadconditions. Tractor trolley or trailers are very popular and cheaper mode of goods transport inrural as well as urban area. But these trailers are manufactured in small scale to moderatescale industry. Especially in the small- and middle-scale agricultural machinery industry,insufficient use of new technology and new design features can cause problems such asbreakdowns and failures during field operations. In present work finite element analysis approachis used to make a safer working condition of trolley axle as well as for stress concentration,weight and cost reduction of existing trolley axle.

Keywords: Trolley axle, Safety working condition, Cost reduction, PROE, ANSYS 12

INTRODUCTIONIn the present market scenario, cost reductiontechnique is playing significant role to meet thecompetition in the market. Weight reduction andsimplicity in design are application of industrialengineering. Various components or products,such as, farming machinery, thrashers, tractor’s

ISSN 2278 – 0149 www.ijmerr.comVol. 2, No. 3, July 2013

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Int. J. Mech. Eng. & Rob. Res. 2013

1 Mechanical Engg. Department, B N College of Engg. Pusad, S.G.B.A. University, Amravati, India.

trolley, etc., mostly used in rural areas aremanufactured in small scale industries. It hasbeen observed that these products may notproperly design. These products aremanufactured as per need, by trial and errormethods of manufacturing. So these productsare required to design properly.

Research Paper

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Farm tractor is an off road vehicle, used asa portable machine to do various useful workssuch as farming, haulage, heavy earthmovingand transportation. An off-road vehicle isconsidered to be any type of vehicle which iscapable of driving on and off paved or gravelsurface. Off road condition includes unevenagricultural field surfaces and bumpy villageroads on which the tractor has to operate.These ground irregularities leads tounexpected loads coming on the tractorcomponents. Tractor trolley or Trailers arewidely used for transporting agricultureproduct, building construction material,industrial equipments and many other typesof goods. Many varieties are available in trailerand use of particular trailer depends upon theapplication. The main requirements of trailermanufacturing are high performance withlonger working life and robust construction.Tractor trolleys used for transportation aremanufactured in small to moderate scaleindustries. Though tractor trolleys aremanufactured of various capacities by variousindustries, there is a variation in manufacturingmethods. The axle of a tractor trolley is one ofthe major and very important component andneeds to be designed carefully, science thispart also experiences the worst load conditionsuch as static and dynamic loads due toirregularities of road, mostly during its travelon off road. Therefore it must be resistant totolerate additional stress and loads.

In our project work, finite element analysisapproach will be used (by considering changein materials and change in existing shape andsize). A CAD model of existing trolley axle isprepared using Pro-E wildfire 4.0 softwarethen analysis is done with the help of Ansys

workbench. The main purpose of project is tomake a safer working condition of trolley axleas well as for stress concentration, weight andcost reduction.

Local Industries in MIDC, Akola, is presentlythe leading manufacturers of tractor trolleysproducing about 2000 trolleys per annum. Theanalysis and discussion with owner of localIndustries in MIDC, Akola, revealed that withproper design approach, the cost of trolley axlecan be reduced. As there is lot of competitionin the market, so reduction in cost isnecessary.

MATERIALS AND METHODS

Methodology

The experimental analysis of trolley axle is donewith the help of new technology of CAD/CAE.

For Designing: CAD software like Pro-E.

For FE Analysis: ANSYS WORKBENCH.

Tractor Trolley Axle

The axle of a tractor trolley is one of the majorand very important components and needs tobe designed carefully, since this part alsoexperiences the worst load condition such asstatic and dynamic loads due to irregularitiesof road, mostly during its travel on off road.Therefore it must be resistant to tolerateadditional stress and loads.

Trolley axle under consideration is asupporting shaft on which a wheel revolves.The axle is fixed to the wheels, fixed to itssurroundings and a bearing sits inside the hubwith which a wheel revolves around the axle. Atrolley axle is also called as beam axle whichis typically suspended by leaf springs asshown in Figure 2.

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Material Selection

Materials science and engineering plays a vitalrole in this modern age of science andtechnology. Various kinds of materials areused in industry, housing, agriculture,transportation, etc. to meet the plant andindividual requirements. The rapiddevelopments in the field of quantum theory ofsolids have opened vast opportunities forbetter understanding and utilization of variousmaterials.

So for better design and reduce the cost ofmaterial we compare the three materials:(a) SAE-1020, (b) SAE 1040, (c) Ductile CastIron 80-55-06.

SAE-1020: The SAE-1020 grade steelmaterial is existing material used for the axlewhich having carbon percentage up to 0.17-0.23 and percentage of silicon 0.15-0.35, alsothe density of material is 7870 (Kg/m3) and itsultimate strength is 420 MPa. This material isgenerally used for making the farmingequipments and industrial purpose.

SAE 1040: The SAE-1040 grade steelmaterial is proposed material for the axle oftractor trolley, this material have the goodproperties than the SAE 1020 steel grade,its having the carbon percentage up to 0.37-0.44 and percentage of silicon 0.35,thepercentage of carbon is higher than the SAE1020 steel grade material. Also it’s havingdensity up to 7845 (Kg/m3) and its ultimatestrength is 595 MPa.

Ductile Cast Iron 80-55-06: Ductile iron iscompetitive with steel in strength for a given levelof ductility and 8-10% lower in specific gravitythan wrought steel. Ductile cast iron round barswere prepared using alloys with CarbonEquivalent percentage (CE) ranging between4.50% and 4.76%. Different measurementswere carried out on as—cast and heat-treatedspecimens. Ductile cast iron is essentially afamily of materials with a wide verity ofproperties which are satisfactory for differentengineering requirements. The soft ferritegrades are available to use when toughnessand ductility are needed, while the harderpearlitic grades are used when higher strengthis required. Grades with mixture of pearlite andferrite in the matrix are also available.

Figure 1: Axle Assembled with Leaf Spring

Figure 2: Step Turned Trolley Axle

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Material Property

the axle at two point C and E as shown in loaddistribution diagram.

• Determination of reaction at support.

• Determination of value of shear force atchange of load position.

• Determination of values of bending momentat change of load point.

SAE 1020 (Existing Axel) 420 370 7870 205000 0.29

SAE 1040 595 515 7845 200000 0.29

Ductile Cast Iron 80-55-06 559 370 7150 168000 0.31

Table 1: Mechanical Material Properties

UltimateStrength (MPa)

Yield Strength(MPa)

Density(Kg/m3)

Modolus ofElasticity (MPa)

PoissonsRatio

Material

LOADING ON AXLEStatic Load on Axle

The static load on axle is calculated byconsidering the fully loaded trolley model. Astatic analysis calculates the effects of steadyloading conditions on a structure, whileignoring inertia and damping effects, such asthose caused by time-varying loads. Staticanalysis determines the displacements,stresses, strains, and forces in structures orcomponents caused by loads that do notinduce significant inertia and damping effects.

Static Load Analysis

The total capacity of the trolley is 60 KN butself weight of trolley and the axle assembly is13 KN. So we consider the gross weight comeover the axle is 73 KN. As the leaf spring isused as the isolator and whole weight of thetrolley is mounted over there. Due to leaf springthe total weight of the trolley is transferred over

Figure 3: Shear Force and BendingMoment on Axle

Load PointShear Force Bending Moment

A 36.835 KN 0 KN mm

C 0.335 KN 5525.25 KN mm

D –0.335 KN 5667.62 KN mm

E –36.835 KN 5525.25 KN mm

B 0 KN 0 KN mm

Table 2: Shear Force and BendingMoment on Axle

RA = 36.835 KN RB = 36.835 KN

Design of Existing Axle

An axle is a stationary machine element and isused for the transmission of bending momentonly. It simply act as a support for some rotatingbody such as hoisting drum and in tractor trolleycase the axle is supporting of rotating memberknown as hub for holding the tires.

So the axles are used to transmit bendingmoment only. Thus axles are designed on thebasis of bending moment only.

When the axle is subjected to a bendingmoment only then we get the following data.

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M/I = (fb)/Y

M: Bending moment.

I: Moment of inertia.

fb: Bending stress.

Y: Distance of outer fiber from neutral axis.

Moment of inertia of cross sectional areaof the axle about the axis of rotation.

(I) is equal to 2636718.75 mm4

As we selected the material for axle is SAE1020 (Cold rolled) having bending stress

(fb) (Allowable) is 420 MPa.

Bending moment (M) is found to be29531250 N-mm

The section modulus (z) of the existing axle(75 75 1550 mm) is found to be

z = M/fb = 70312.5 mm3.

We cross check this section modulus byusing data book formulae. Section modulus.

(z) = bh2/6 = 70312.5 mm3.

On the observations of the bending momentwe found that:

When the axle length and the point loadapplied on it is considered then the maximumbending moment is found equal to 5667620N-mm.

When the material is considered and thecross sectional area is considered then themaximum bending moment is found equal to29531250 N-mm

The maximum moment (M) = 5667620N-mm.

• The bending stress (allowable) (fb) = 420

MPa (SAE 1020).

• Section modulas (z) = M/fb = 13494.33

mm3.

• The obtained value of z = 13494.33 mm3 =b3/6 = 43.26 mm.

• b = 45 mm.

So on the basis of bending moment onlywe got the cross section of axle is 45 mm.

Dynamic Load

Trolleys are used in rural areas and on roughroads at moderate speed, i.e., up to 40 kmper hour. On full load conditions the speed is20 km per hour maximum. Due to moderatespeed and wavy road conditions the axle issubjected to dynamic loads which arenonlinear in nature. The load coming on theaxle due to this are much larger than staticloads, which makes it necessary to analysesthe axle for dynamic loads.

Dynamicic Load Analysis

As we know that the dynamic load is alwaysmore than static load but it is not possible todefine the accurate dynamic load, so weconsider as a maximum load due to dynamicloading is 50 KN on each leaf spring.

Figure 4: Shear Force and BendingMoment on Axle

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• The maximum moment (M) = 7695500.00N-mm.

• The bending stress (allowable) (fb) = 420

MPa (SAE 1020).

• Section modulas (z) = M/fb = 18322.62

mm3.

• The obtained value of z = 18322.62 mm3.

(z) = b3/6

18322.62 = b3/6

b = 47.90 mm

b = 50 mm

So by considering the dynamic loadcondition we obtain the cross section of axleis 50 mm.

DESIGNS WITH DIFFERENTC/SDesign the axle while considering maximumbending MOMENT 7695.50 KN/mm for allc/s of axle.

Square Axle

Circular Axle

I-Section Axle

Load PointShear Force Bending Moment

A 50.33 KN 0 KN mm

C 0.33 KN 7555.25 KN mm

D –0.34 KN 7695.50 KN mm

E –50.34 KN 7551.00 KN mm

B 0 KN 0 KN mm

Table 3: Shear Force and BendingMoment on Axle

RA = 50.33 KN RB = 50.34 KN

SAE 1020 Material

Section modulus (z) = M/fb

= 7695.50 * 1003/370

(z) = 20798.65 mm3

(z) = b3/6

20798.65 = b3/6

b = 49.97 mm

b = 50 mm

Table 4: Design of Square Axle for Different Material

SAE 1040 Material

(z) = M/fb

= 7695.50 * 1003/515

(z) = 14942.72 mm3

14942.72 = b3/6

b = 44.76 mm

b = 50 mm

Ductile Cast Iron Material

(z) = M/fb

= 7695.50 * 1003/370

(z) = 21258.29 mm3

21258.29 = b3/6

b = 49.97 mm

b = 50 mm

Figure 5: Square Cross Section Axle

Figure 6: Circular Cross Section Axle

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SAE 1020 Material

Section modulas (z) = M/fb

= 7695.50 * 1003/370

(z) = 20798.65 mm3

32

3DZ

D = 59.61 mm

D = 60 mm

Table 5: Design of round axle for different material

SAE 1040 Material

= 7695.50 * 1003/515

(z) = 14942.72 mm

3272.14942

3D

D = 53.39 mm

D = 60 mm


(z) = M/fb

= 7695.50 * 1003/370

(z) = 20798.65 mm3

32

3DZ

D = 59.61 mm

D = 60 mm

Figure 7: I Cross Section Axle

SAE 1020 Material


(z) = 7695.50 * 1003/370

= 20798.65 mm3

H

bhBHz

6

33

B = 44.94 mm, H = 53.93 mm

b = 22.47 mm, h = 26.96 mm

Table 6: Design of I Cross Section Axle for Different Material

SAE 1040 Material


(z) = 7695.50 * 1003/370

=14942.72 mm3

H

bhBHz

6

33

B = 40.50 mm, H = 48.59 mm

b = 20.25 mm, h = 24.30 mm



(z) = 7695.50 * 1003/370

= 20798.65 mm3

H

bhBHz

6

33

B = 44.94 mm, H = 53.93 mm

b = 22.47 mm, h = 26.96 mm

Assume: H = 1.2 B, h = H/2, b = B/2.

Round Up the Values

B = 45.00 mm, H = 60.00 mm

b = 25.00 mm, h = 30.00 mm

ANALYSISANSYS has developed product lines that allowyou to make the most of your investment andchoose which product works best in your

environment. ANSYS is a Finite ElementAnalysis (FEA) code widely used in theComputer-Aided Engineering (CAE) field. ACAD model of existing trolley axle and newdesigned axle is prepared using Pro-E wildfire4.0 software then analysis is done with the helpof Ansys workbench.

Below figures shows the Equivalent (von-mises) stress on the axle when the load isapplied. Red color shows the maximum stress

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and blue color shows minimum stressgenerated on the axle. For this analysispurpose following data are used.

Comparison of Stresses and Price

Cost ReductionWhen we consider the different c/s of axle withdifferent material then we got minimum weightof axle 23.273 Kg for I-section and material isductile cast iron with price of Rs. 1457.821.

But the minimum cost for axle is obtain forI-section with material SAE 1040 the price is1042.849 and weight of axle is 25.535 Kg.

Compare the existing axle price and new

designed axle minimum price:

Existing axle price is Rs. 2802.10.

New designed axle minimum price is Rs.

1042.849.

So we got the price difference of Rs.

1759.25.

Means by adopting the new design of axle

we can reduce the axle cost up to Rs.

1759.251.

Figure 10: Stress and Deflectionin New Designed Round Axle

Figure 11: Stress and Deflectionin New Designed I Cross Section Axle

Figure 9: Stress and Deflectionin New Designed Square Axle

Figure 8: Stress and Deflectionin Existing Axle

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Akola. For their contributions to provide theimportant data for project work. Also thanks toMechanical Engineering department B NCollege of Engg. Pusad for providing labfacility for Modeling and analysis of axle

REFERENCES1. Abhijit P Birnale and Damodar R Malagi

(2006), Shape Optimization of Front AxleBeam, Engineer Bharat Forge Ltd., Pune.

2. Ali Jafari,Majid Khanali, Hossein Mobliand Ali Rajabipour (2006), StressAnalysis of Front Axle of JD 955Combine Harvester Under StaticLoading, Department of AgriculturalMachinery, Faculty of Bio-SystemEngineering, University College ofAgriculture and Natural Resources,University of Tehran, Karaj, Iran.

3. Calika O Sahinb and Ucarc N (2009),Mechanical Properties of Boronized AISI316, AISI 1040, AISI 1045 and AISI 4140Steels, Department of MechanicalEducation, Technical Education Faculty

SAE 1020 Square (Existing Axle) 94.121 0.227 68.616 2802.100

SAE 1020 SQUARE 317.660 1.347 30.496 1245.466

ROUND 327.387 1.107 34.490 1408.589

I-SECTION 259.525 0.960 25.616 1046.157

SAE 1040 SQUARE 317.660 1.381 30.399 1241.510

ROUND 327.387 1.135 34.552 1403.900

I-SECTION 259.525 0.984 25.535 1042.849

Ductile Cast Iron SQUARE 317.660 1.644 27.625 1730.422

ROUND 327.387 1.352 31.294 1962.511

I-SECTION 255.863 1.117 23.273 1457.821

Table 7: Comparison of Stresses and Price for Different Cross Section Axle

Material Shape of Axle MaximumStresses (N/mm2)

Elongation(MM)

Mass of Axle(Kg)

Price/Piece(Rs.)

CONCLUSIONThis study was conducted on an existing rearaxle shaft used in tractor trolley shows that theexisting axle has greater factor of safety soun-wontedly heavy axle is used for trolley inexisting condition which increase the weightof axle as well as cost of axle. But the newlydesigned axle with different cross section anddifferent material show that we can maximallyreduces the 33.92% weight as compare to theexisting axle shown in comparison table. Alsoreduces the cost of trolley axle as the weightof the axle reduces. We reduce the cost of axleapproximately up to Rs. 1759.251 per axle andthe deformations as well as stressesdeveloped in new designed axle are in withinlimits the minimum cost obtained for I crosssection axle of SAE 1040 material, thedeformation for that axle is 0.984 mm andstresses developed in that axle is 259.525(N/mm2) which are in within limit.

ACKNOWLEDGMENTWe would also like to thank Vidharbha trolleyand farming Equipment Company Ltd. MIDC

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Suleyman Demirel University, Isparta,Turkey.

4. Dilip K Mahanty, Vikas Manohar, BhushanS Khomane and Swarnendu Nayak(2001), Analysis and Weight Reductionof a Tractor’s Front Axle, Tata ConsultancyServices, India.

5. Javad Tarighi, Seyed Saeid Mohtasebiand Reza Alimardani (2011), Static andDynamic Analysis of Front Axle Housingof Tractor Using Finite Element Methods,Department of Agricultural MachineryEngineering, Faculty of Engineering andTechnology, University of Tehran, PO Box4111, Karaj 31587-77871, Iran.

6. Ji-Xin Wang, Guo-Qiang Wang, Shi-KuiLuo and Dec-Heng Zhou (2012), Staticand Dynamic Strength Analysis on RearAxle of Small Payload Off-highwayDump Trucks, College of MechanicalScience and Engineering, Jilin University,Nanling.

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