Shear test final.doc

8/14/2019 Shear test final.doc

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KWAME NKRUMAH UNIVERSITY OF SCIENCE

AND

TECHNOLOGY

DEPARTMENT OF MECHANICAL ENGINEERING

MECHANICAL ENGIEERING LAB III ME 395

TITLE: SHEAR TEST ON RUBBER

Group 20

Name I!e" No#

AGBAVOR DANIEL ATSU YAO $%&''(0

MAMUD MUSTA)HA $%$(*(0

COFIE FREDERICK CARLTON $%&%+(0

AFRIEYIE,DUAH SAMUEL $%&'$(0

(0-(0-20(2


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OB.ECTIVE

To determine the mod!" o# ri$idit% G o# r&&er

A))ARATUSThe "et ' o# the e('eriment )*" the Norton "he*r te"t m*+hine )hi+h +on"i"t" o# * &ro*d

)ooden &*"e "er,in$ *" "''ort #or the entire "et'- * +!*m' )hi+h "er,e" *" "''ort #or

the di*! $*$e *nd * '!!e% h*,in$ * thre*d *tt*+hed to the !o*d *rm- rn o,er it.The r&&er nder te"t i" monted on the )ooden &*"e/ in0 &et)een the di*! $*$e *nd the

'!!e% "''ort "+h th*t- the ti' o# the di*! $*$e 1"t to+he" the r&&er.

DIAGRAM OF SETU)

METHOD

The thi+2ne"" *nd hei$ht o# the r&&er nder te"t )ere me*"red )ith * ,ernier +*!!i'er.The !en$th o# the r&&er )*" *!"o me*"red *nd the me*"rement" re+orded.

The di*! $*$e )*" "et to it" ero m*r2.The *''*r*t" )*" then !o*ded )ith !o*d" #rom 4!& to 6!& in in+rement" o# 7!& *nd the+orre"'ondin$ "te*d% de#!e+tion" on the di*! $*$e )ere t*2en.

Con,er"e!% the *''*r*t" )*" then n!o*ded )ith !o*d de+rement" o# 7!& *nd the

+orre"'ondin$ "te*d% de#!e+tion" o# the di*! $*$e- *++ordin$!% t*2en.

A t*&!e o# ,*!e" #or &oth !o*din$ *nd n!o*din$ )*" dr*)n *#ter )hi+h * $r*'h o# !o*d*$*in"t de#!e+tion )*" dr*)n.THEORY


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G 8 "he*r "tre"" 8 ; &t "tre"" 8 #or+e *re*

8 di"tortion 'rod+ed &% "he*r "tre"" on r&&er

T*n > 8 ; h #or "m*!! *n$!e" t*n > 8 > > 8 ; h

; 8 de#!e+tion o# it #rom the ori$in*!

The mod!" o# ri$idit% o# the r&&er- G i" $i,en &%

G 8 ?F L=B@ = h;

There#ore the #or+e- F i" $i,en &%

F 8 GLB; H

F 8 ?GLB H@ ?;@

Com'*rin$ )ith *n e*tion o# * "tr*i$ht !ine 8 m( +

F 8 m; +

Thi" im'!ie" th*t

F 8 GLB ?;@ +

Hhen * $r*'h o# #or+e i" '!otted *$*in"t de#!e+tion- ; * "tr*i$ht !ine $r*'h )i!! &e

$ener*ted )ith "!o'e ?m@ 8 GLB H

Then m*2in$ G the "&1e+t o# the *&o,e re!*tion- it &e+ome"

G 8 "!o'e ?m@ = H


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L=B

TABLE OF VALUES

Lo*d De#!e+tion m !& $ !o*din$ n!o*din$

4 4 4 6

7 4.94 9 34

. 9

6 7.7 79 55

3.67 4 65

4 .535 57 5

7 5.7 67 7

6.39 5

6 .756

De#!e+tionmm

Lo*dN

0 1 2 3 4 5 6 7 8

0

10

20

30

40

50

60

70

80

90

100


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Determin*tion o# mod!" o# Ri$idit% ?G@

Thi+2ne"" o# r&&er 8 7.5+m

Hei$ht o# r&&er 8 .7+m

Len$th o# r&&er 8 35.+m

From the $r*'h the "!o'e ?m@ 8 4.44 4.477 8 4.43

7

There#ore-

G 8 "!o'e ?m@ = H L=B

G 8 4.43 = 4.7 8 3.39407Nm

4.35 = 4.4759

The e('eriment*! mod!" o# ri$idit% o&t*ined i" 3.39407Nm

COMMENTS AND CONCLUSIONS

The $r*'h o# !o*d *$*in"t de#!e+tion #or &oth !o*din$ *nd n!o*din$ h*,e * !ine*r

re!*tion"hi' or in+re*"ed !ine*r!% #or mo"t '*rt o# the +h*rt nti! *t * 'oint )hen the% &oth

*""med * +r,e "h*'e.Thi" e('!*in" the #*+t th*t Hoo2e" !*) ho!d" #or the m*teri*!

nder in,e"ti$*tion.

hen the m*teri*! )*" !o*ded )ithin it" e!*"ti+ r*n$e- the de#!e+tion )*" 'ro'ortion*! to

the !o*d. A 'oint )*" ho)e,er re*+hed )hen the de#!e+tion h*d no !ine*r re!*tion"hi')ith the !o*d *''!ied. Thi" o++rred )hen the e!*"ti+ !imit o# the m*teri*! )*" e(+eeded

i.e. the '!*"ti+ r*n$e )*" *''ro*+hed. The $r*'h *tt*ined * m*(imm 'oint *nd

m*int*ined th*t nti! *t * 'oint )hen it +o!d %ie!d.

Drin$ !o*din$ o# the m*teri*!- there )*" *n ind+ed intern*! ener$% in the "'rin$ *" )e!!

*" the "trin$ ho!din$ the !o*d *rm. The ener$% i" ho)e,er red+ed drin$ n!o*din$ &t


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not entire!% e!imin*ted. The 're"en+e o# tho"e e!ement*! ener$ie" in the "trin$ i" the m*in

re*"on #or the !o*din$ *nd n!o*din$ 'oint" not +oin+idin$ )hen the $r*'h )*" '!otted.

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