Analysis of Stress Singularities on Interfaces of Friction Welded Dissimilar Materials

C o p y r ig h t 2 0 0 5 K S A E 1 2 2 5 - 6 3 8 2 / 2 0 0 5 / 0 7 4 - 2 0 T r a n s a c tio n s o f K S A E , V o l. 1 3 , N o . 2 , p p .1 4 2 -1 4 8 (2 0 0 5 )

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(d is s im ila r m a te ria ls )

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Analysis of Stress Singularities on Interfaces of Friction Welded Dissimilar Materials

Namyong Chung

Chul Hee Park

1)Department of Mechanical Engineering, Soongsil University, Seoul 156-743, Korea

2)Hyundai Technical Institute, 158-487 Gwangmyung4-dong, Gwangmyung-si, Gyeonggi 135-080, Korea (Received 8 October 2004 / Accepted 31 December 2004)

A b s t r a c t : In th is p a p e r, th e s tre s s s in g u la rity o n in te rfa c e o f fric tio n w e ld e d d is s im ila r m a te ria ls w a s in v e s tig a te d b y u s in g 2 -d im e n s io n a l e la s tic b o u n d a ry e le m e n t m e th o d . It is re q u ire d th a t s tre s s d is trib u tio n s a n d s tre s s s in g u la ritie s o n a n in te rfa c e fo r fric tio n w e ld e d d is s im ila r m a te ria ls a n a liz e to e s ta b lis h s tre n g th e v a lu a tio n . T h e s tre s s s in g u la rity in d e x ( ) a n d s tre s s s in g u la rity fa c to r ( ) w e re c a lc u la te d fro m th e re s u lts o f s tre s s a n a ly s is . T h e s tre s s s in g u la ritie s o n v a ria tio n s fo r s h a p e s a n d th ic k n e s s o f fric tio n w e ld e d fla s h e s w e re a n a liz e d a n d d is c u s s e d . T h is p a p e r s u g g e s te d th a t th e s tre n g th e v a lu tio n b y u s in g th e s tre s s s in g u la rity fa c to rs a s fra c tu re p a ra m e te rs , c o n s id e rin g th e s tre s s s in g u la rity o n a n in te rfa c e e d g e o f fric tio n w e ld e d d is s im ila r m a te ria ls w e re v e ry u s e fu l.

K e y w o r d s : F ric tio n w e ld in g ( ), D is s im ila r m a te ria ls ( ), In te rfa c e e d g e ( ), B o u n d a ry

e le m e n t m e th o d ( ), S tre s s s in g u la rity in d e x ( ), S tre s s s in g u la rity fa c to r( ),

F ra c tu re p a ra m e te r( ), W e ld e d fla s h ( )

.

,

, ^{8 ,9 )}

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(S T S 3 0 4 ) A l (6 0 6 1 -T 6 )

(b o u n d a ry e le m e n t m e th o d : B E M ) ,

. .

2 .

2 .1 F ig . 1

. r

d_N d ~

( b u t t j o i n t ) , d_ ~ ppd_N~ (s in g le -la p

Fig. 1 Model of an interface edge in dissimilar materials

jo in t), d_ d_N ~ ^.

,

V .

2 .2

(a) Without flash

(b) With flash

Fig. 2 Model of BEM analysis on friction welded dissimiliar materials

F ig . 2 (a ) S T S 3 0 4 / A l F ig . 2 (b ) 2 m m , 4

m m , 6 m m C 0 .1 m m ,

0 .3 m m , 0 .5 m m , 1 m m ,

= 0 .3 3 ( = 2 m m , = 6 m m ), = 0 .5 ( = 2 m m ,

= 4 m m ) 0 .1 m m , 0 .3 m m , 0 .5 m m , 1

m m

F ig . 2 (b )

. F ig .

2 2 (is o p a ra m e tric )

. 1 4 0 ,

1 6 8

N a m y o n g C h u n g C h u l H e e P a r k

(s u b ) .

T a b le 1 .

Table 1 Mechanical properties of materials M e c h e n ic a l

p ro p e rtie s

M a te ria ls

Y o u n g ,s m o d u lu s E (G P a )

P o is s o n ,s ra tio

S T S 3 0 4 1 9 3 0 .3

A lu m in u m a llo y 7 0 .3 0 .3 4 5

2 .3 F ig . 1

B o g y^{1 0 )} .

R .

(1)

, ,

,

. ,

. , < 0

.^{1 0 )}

(2)

, ,

.^{1 0 )} (3)

, D u n d e rs

.^{1 1 )}

(4)

(4 ) .

X!ä

X!Ôç , (5)

(6)

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! ö & ^.

(7)

, .

(8) (3 )

,

.

3 .

3 .1

K e l v in

F i g . 3 B E M

. ( 3 )

A n a ly s is o f S t r e s s S in g u la r it ie s o n I n t e r f a c e s o f F r ic t io n W e ld e d D is s im ila r M a t e r ia ls

Fig. 3 Stress singularity at an interface edge on friction welded dissimilar materials (c=0)

B E M .

F ig . 2 (b ) .

3 .2

3 .2 .1

F ig . 4 F ig . 5

. . 3 .2 .2

F ig . 6 F ig . 7 (s id e

a tta c h e d le n g th ) 2 m m 0 .1

m m , 0 .3 m m , 0 .5 m m , 1 m m

. .

F ig . 8 = 4 m m , F ig . 9 6 m m

. 0 .1 m m 0 .3 , 0 .5 , 1

m m

0 .3 m m , 0 .5 m m

. 6 m m

.

Fig. 4 Normal stress distribution at an interface edge on friction welded dissimilar materials (c=0, t=0)

Fig. 5 Shear stress distribution at an interface edge on friction welded dissimiliar materials (c=0, t=0)

Fig. 6 Normal stress distribution at an interface edge on friction welded dissimiliar materials (t=2mm)

Fig. 7 Shear stress distribution at an interface on friction welded dissimiliar materials (t=2mm)

Fig. 8 Normal stress distribution at an interface edge on friction welded disimiliar materials (t=4mm)

Fig. 9 Normal stress distribution at an interface edge on friction welded disimiliar materials ( t=6 mm)

3 .2 .3

F ig . 1 0 2 m m , 6 m m ,

F ig . 1 1 2 m m , 4 m m

.

.

Fig. 10 Normal stress distribution at an interface edge on friction welded disimiliar materials (t1/t2 = 0.33)

Fig. 11 Normal stress distribution at an interface edge on friction welded dissimilar materials (t1/t2 = 0.5)

4 .

B E M 3 .1

(1 )

.

(8)

B E M

.

4 .1 Fig. 12 B E M

, .

(8 )

0 .9 8 2 4 5 .

Fig. 12 Extrapolation of stress singularity factor on dissi- milar friction welded materials

4 .2 F ig . 1 3

.

. 6 m m

Fig. 13 Total stress singularity factor for variation of flash thickness

.

4 .3

F ig . 1 4 0 .3 3 0 .5

. 0 .3 3

0 .5

.

Fig. 14 Total stress singularity factor for variation of flash thickness

N a m y o n g C h u n g C h u l H e e P a r k

,

.

5 .

S T S 3 0 4 /A l

(6 0 6 1 -T 6 ) B E M

.

1 ) S T S 3 0 4 /A l

. 2 )

. 3 )

, . 4 )

, .

.

R e fe r e n c e s

1 ) H . S . J e o n g a n d T . S h in d a , “ F u n d a m e n ta ls a n d B a s ic A p p lic a tio n o f F r ic tio n W e ld in g ,” J . o f K W S , V o l.9 , N o .6 , p .1 , 1 9 9 7 .

2 ) S . K . O h , “ R e a l - t i m e E v o l u t i o n o f A u t o m a t i c

P r o d u c tio n Q u a lity C o n tr o l f o r F r ic tio n W e ld - in g M a c h in e ,” J . o f K S M E , V o l.9 , N o .6 , p p .7 5 7 - 7 6 6 , 1 9 8 5 .

3 ) “

N o .9 , p p .1 0 4 - 1 0 7 , 2 0 0 2 .

4 ) K . S . K im , H . S . K im a n d N . Y . C h u n g ,

“ A n a ly s is o f S tr e s s S in g u la r ity o n C e r a m ic / M e ta l B o n d e d J o in ts ,” J . o f K S M E , V o l.2 0 , N o .1 0 , p p .3 0 5 8 - 3 0 6 7 , 1 9 9 6 .

5 ) K . S . K im , H . S . K im a n d N . Y . C h u n g ,

“ E v a lu tio n o f S ta tic S tr e n g th o n C e r a m ic /M e ta l B o n d e d J o in ts C o n s id e r in g S tr e s s S in g u la r ity ,”

J . o f K S M T E , V o l.6 , N o .1 , p p .5 9 - 6 8 , 1 9 9 7 . 6 ) N . Y . C h u n g a n d J . H . Y i, “ E v a lu tio n M e th o d

o f B o n d e d S tr e n g th in A d h e s iv e ly B o n d e d S tr u c tu r e s o f th e A lu m in u m A llo y s ,” J . o f K S M T E , V o l.8 , N o .1 , p p .3 5 - 4 4 , 1 9 9 9 .

7 ) N . Y . C h u n g , S . I . P a r k , M . D . L e e a n d C . H . P a r k , “ U ltr a s o n ic D e te c tio n o f I n e r f a c e C r a c k in A d h e s iv e ly B o n d e d D C B J o in ts ,” I n t. J . A u to m o tiv e T e c h n o lo g y , V o l.3 , N o .4 , p p .1 5 7 - 1 6 3 , 2 0 0 2 .

8 ) D . G . L e e , S . Y . L e e , J . K . J u n g a n d J . Z h a n g ,

“ A n E v a lu a tio n o f F a tig u e P r o p e r tie s o n D is s im ila r F r ic tio n W e ld o f H e a t- R e s is tin g S te e ls U s e d in V e h ilc e V a lv e s ,” J o u r n a l o f K S A E , V o l.1 0 , N o .2 , p p .1 8 6 - 1 9 2 , 2 0 0 2 . 9 ) S . O . O h , C . W . H u e , J . W . Y o o a n d J . C . K im ,

“ A S tu d y o n th e R u p tu re a n d C r a c k P r o p a g a tio n C h a r a c te r is tic s in th e M te r ia l F r ic tio n - W e ld e d w ith H e tr o g e n e o u s S te e ls o f 4 0 C a n d S T S 3 0 4 ,”

J . o f K W S , V o l.1 0 , N o .4 , p p .2 3 0 - 2 3 9 , 1 9 9 2 1 0 ) D . B . B o g y , “ T h e P la n e S o lu tio n f o r J o in e d

D is s im ila r E la s tic S e m is tr ip s u n d e r T e n s io n s ,”

J . A p p l. M e c h , V o l.4 2 , p p .9 3 - 9 8 , 1 9 7 5 . 1 1 ) J . D u n d e r s , “ D is c u s s io n o f E d g e - B o n d e d D is s i-

m ila r O r th o g o n a l E la s tic W e d g e s u n d e r N o r m a l

a n d S h e a r L o a d in g ,” J . A p p l. M e c h , V o l.3 6 ,

p p .6 5 0 - 6 5 2 , 1 9 6 9 .