design and analysis of knuckle joint

8/16/2019 Design and Analysis of Knuckle Joint

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DESIGN AND ANALYSIS OFKNUCKLE JOINT

byHARSHA VARDHAN PUNNA S

Guided byDr. PERIASAMY


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ABSTRACT• The aim of the present project is to study the stresses in Knuckle joint

using analytical method. A knuckle joint is designed for increasingthe capacity to withstand load. It is proposed that instead of mild steelhigh strength high modulus Molybdenum can be used for further

enhancing the capacity to withstand higher loads. The knuckle joint proposed work is to study the behavior of pin for an applied force of1 ! K". The diameter of the pin is proposed to be around # mm andthe factor of safety of #. $A% model of knuckle is prepared in$ATIA. &tatic analysis is done in A"&'& by constraining the

knuckle and for applied loads( the stress contour( displacementcontour( strain energy contour are obtained. These )inite *lementAnalysis results are verified by comparing with analyticalcalculations.


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INTRODUCTION• Knuckle joint is one of the important components of vehicle which

is used to transmit a+ial tensile force. • Knuckle joint is used to connect two rods whose a+es either

coincide or intersect and lie in one plane.• A knuckle joint may be failed on the following three modes

1. &hear failure of pin ,single shear-.#. $rushing of pin against rod.

. Tensile failure of flat end bar.• A//0I$ATI "&2

– 3oint in the car steering – 3oint between the links of a bicycle chain – 3oint in the tractor


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Parts of knuckle joint


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BENDING FAILURE OF PIN

• 4hen the pin is tight in the eye and the fork( failure occurs due toshear.

• n other hand( when the pin is loose( it is subjected to bendingmoment.

• It is assumed that the load acting on the pin is uniformly distributedin the eye( but uniformly varying in two parts of the fork.


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MATERIAL

• The material of the knuckle joint is considered as Molybdenum inorder to do the stress analysis.

• Molybdenum( a refractory metal is widely used as an alloyingelement.

• It has good thermal and electrical conductivity( high melting pointand e+cellent strength.

• Molybdenum can be used for various applications in its pure form.• /roperties2

Tensile stress 5 #6M/a&hear stress 5 !!M/a$ompressive stress 5 6!!M/a


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DESIGN STANDARDI ATION


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DESIGN CALCULATIONSThe rods are subjected to direct tensile load( Therefore tensile strengthof the rod(

/ 5 ,786- 9 + : t1 !!!!5,786-+ #6

d5#6mm%iameter of the rod ,d-5#6mm%iameter of pin( d 1 5 d5#6mm

uter diameter of eye( d # 5 #d56;mm

%iameter of knuckle pin head and collar( d 5 1. d5


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F!i"ure #$ %&e '(u)'"e *i( i( +&e!r,&ince the pin is in double shear( therefore cross>sectional area of the pin

under shearing/ 5 # + ,786- 9 ,d1+ s 1 !!!!5# + ,786- 9 ,#6+ s

+- /0.12MP!

It is less than allowable shear stress so it is safe.The value of ma+imum bending moment is given by2 M 5 ?,/8#- @,t 18 - ,t8#-BC D ?,/8#-+ ,t86-C

M 5 ,/8#- ?,t 18 - ,t86-C

M - 3 4.0 KN566 And section modulus(E 5 ,78 #- + ,d1 &ince ma+imum bending ,tensile- stress(:t5 M8E

d - 74 66

•


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F!i"ure #$ %&e +i(8"e eye #r r#d e(d i( %e(+i#(,The single eye or rod end may tear off due to the tensile load

/ 5 ,d # D d1- t 9 : t1 !!!!5,6;> #-+ !+: t

9 %-7 4.0 MP!

F!i"ure #$ %&e +i(8"e eye #r r#d e(d i( +&e!ri(8,The single eye or rod end may fail in shearing due to tensile load.

/ 5 ,d # D d1- t 9 s 1 !!!!5,6;> #-+ !9 s

s- 312 ! MP!F!i"ure #$ %&e +i(8"e eye #r r#d e(d i( )ru+&i(8,

The single eye or pin may fail in $rushing due to the tensile load. / 5 d 1 9 t 9 : c 1 !!!!5 #+ !+: c

9 )-431MP!

•


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F!i"ure #$ %&e $#r'ed e(d i( %e(+i#(,The forked end or double eye may fail in tension due to the tensile load.

/ 5 ,d # D d1- 9 #t 1 9 : t 1 !!!!5#,6;> #-1;+: t

9 %-4/3.:MP!

F!i"ure #$ %&e $#r'ed e(d i( +&e!r,The forked end may fail in shearing due to the tensile load.

/ 5 ,d # D d1- 9 #t 1 9 s 1 !!!!5#,6;> #-1;+ s

+- 2"# $ MP!F!i"ure #$ %&e $#r'ed e(d i( )ru+&i(8,

The forked end or pin may fail in crushing due to the tensile load. / 5 d 1 9 # t 1 9 : c1 !!!!5 #+#+1;+: c

9 )- 27./MP!

•


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MODELLING


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RESULT AND ANALYSIS


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Knuckle joint with boundary condition


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von>mises stress


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Ma+imum principal stress


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&hear stress


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Total deformation


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&tresses and %eformation results ofMolybdenum

S.(# Ty*e+

M!; Mi(

&hear stress,+y plane-

#6F.; Mpa

4 Total deformation

!.!F61! mm !.!! mm

7 Ma+imum principal

&tress

= 6.F Mpa >6 .#=# Mpa

: Gon mises stress

#.F Mpa 1.6F!= Mpa


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THEORETICAL CALCULATION

N#r6!" +%re++ i( ;5; dire)%i#(,-

/ 5 1 !!!! " A 5 ;! .;6 mm #

- - 1;M!;i6u6 *ri()i*!" +%re++,H 5 ! + !. 5 1< "8mm #

5 -

- #


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Mi(i6u6 *ri()i*!" +%re++, 5 D- >

M!;i6u6 +&e!r +%re++, 5-

- 1


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$omparison of results

S%re++ T&e#re%i)!" A""#

M!;i6u6 *ri()i*"e +%re++ #


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CONCLUSION

• The knuckle joint designed in the present study is for withstanding anapplied force of 1 ! K". The diameter of the pin is proposed to bearound #6 mm. The material of the knuckle joint is considered asmolybdenum. Jased on the above( a $A% model was developed

using $ATIA. In order to carry out the stress analysis( mesh wasdeveloped for the knuckle joint. A"&'& software was run and thestress contour( displacement contour( strain energy contour wereobtained.

• Jased on the A"&'& analysis( it shows that a pin of #6 mm diameter

can withstand a load of 1 ! k" if a factor of safety of # is used. The)*A is carried out for knuckle joint model and the result of analysisindicate that the von mises stress has changed from #.F Mpa to1.6F!= Mpa. ence the design is safe.


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REFERENCES

1. 3.K. Lupta( .&. Khurmi. A textbook of machine design . am "agar( "ew %elhi2 *urasia /ublishing ouse. I&J" ;1>#1F># =>1 ,#!!;-.#.NKnuckle3oint.N Merriam-Webster.com .Merriam4ebster(4eb.16%ec.#!1 .

http288www.merriamwebster.com8dictionary8knuckle jointO.. 3ones % ( *ngineering Materials D materials failure analysis.+ford ,PK- /ergamon /ress ,1FF -.

6. Jhandari( G.J. ,#!!1-. Introduction to machine design. "ew %elhi2Tata McLraw> ill.#!!1.

. 3oseph *. &higley( $harles . Mischke( Thomas . Jrown( ,#!!6-.Standard handbook of machine design , rd ed-. "ew 'ork2 McLraw>

ill. I&J" F=;>!>!=>1661

design and analysis of knuckle joint

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