8/12/2019 University Question Paper MAY 2005

1/3

R 113

B.E/B.Tech DEGREE EXAMINATION, APRIL/MAY 2005

Fourh !e"e#er

Mech$%&c$' E%(&%eer&%(

)E 251 * !TRENGT+ OF MATERIAL!

Time : Three hours Maximum : 100 marks

Answer ALL questions

PART A (10 2 = 20 marks)

1 !eri"e a re#ation $or %han&e in #en&th o$ a 'ar han&in& $ree# uner its own wei&ht

2 A 'rass ro 2 m #on& is $ixe at 'oth its ens *$ the therma# stress is not to ex%ee +,-

./mm2 a#%u#ate the temerature throu&h whi%h the ro shou# 'e heate Take the

"a#ues o$ an 3 as 1+ 104,/5 an 60 7Pa rese%ti"e#

8 !raw the shear $or%e ia&ram $or a sim# suorte 'eam o$ - m san is su'9e%te

to a %#o%kwise moment o$ 1-k.m at istan%e o$ 2 m $rom the #e$t en

;ket%h the 'enin& an shear stress istri'ution $or

8/12/2019 University Question Paper MAY 2005

2/3

PART B (- 1, = 0 marks)

11 (i) ;tate Moment4Area MohrCs theorem ()

(ii) A sim# suorte 'eam AB uni$orm se%tion? m san is su'9e%te to a

%#o%kwise moment o$ 10 k.m a#ie at the ri&ht hin&e B !eri"e the equation

to the e$#e%te shae o$ the 'eam Lo%ate the oint o$ maximum e$#e%tion an

$in the maximum e$#e%tion (12)

12 (a) (i) !eri"e a re#ation $or %han&e in #en&th o$ a 'ar o$ uni$orm# taerin&

%ir%u#ar se%tion su'9e%te to an axia# tensi#e #oa DEC ()

(ii) A rein$or%e %on%rete %o#umn -00 mm -00 mm in se%tion is

rein$or%e with stee# 'ars o$ 2- mm iameter? one in ea%h %orner?

the %o#umn is %arrin& a #oa o$ 1000 k. >in the stresses in the

%on%rete an stee# 'ars Take 3 $or stee# = 210 108./mm2an 3

$or %on%rete = 1 108./mm2 ()

Fr

(') A sim# suorte 'eam is #oae as shown in $i& G 12 (') !raw the shear

$or%e an 'enin& moment ia&rams ()

18 (a) A so#i sha$t is su'9e%te to a torque o$ 100 .m >in the ne%essar sha$t

iameter i$ the a##owa'#e shear stress i 100 ./mm2an the a##owa'#e twist is 8

er 10 iameter #en&th o$ the sha$t Take = 1 10-./mm2

(1,)

8/12/2019 University Question Paper MAY 2005

3/3

Fr

(') (i) ;tate an $our assumtions mae in the theor o$ sim#e 'enin&

()

(ii) !eri"e the 'enin& $ormu#a M/* = $/ = 3/R (12)

1 (a) A thin %#inri%a# she## 1- m #on&? interna# iameter 800 mm an wa## thi%kness

10 mm is $i##e u with at atmosheri% ressure *$ the aitiona# $#ui o$ 800

108 mm8 is ume in the she##? $in the ressure exerte ' the $#ui on the

she## Take 3 = 2 10- M/mm2 an 1/m = 08 A#so $in the hoo stress

inu%e (1,)

Fr

(') (i) !eri"e a re#ation $or e$#e%tion o$ a %#ose# %oi#e he#i%a# srin&

su'9e%te to an axia# ownwar #oa E ()

(ii) A quarter e##iti% #ea$ srin& ,0 %m #on& is mae o$ stee# #ates

with 10 times the thi%kness The srin& is to %arr a #oa o$ 8k.

an the en e$#e%tion is #imite to - %m the 'enin& stress o$ the

#ates must not ex%ee 8000 ./mm2 >in suita'#e "a#ues o$ the

siHe an num'er o$ #ates to 'e use Take e = 2 10-./mm2 ()

1- (a) A %anti#e"er o$ #en&th 2 is %arrin& a #oa o$ E at the $ree en? an another

#oa o$ E at its %entre !etermine ' moment area metho? the s#oe an

e$#e%tion o$ the %anti#e"er at the $ree en (1,)

Fr

(') (i) !eri"e a re#ation $or strain ener& store in a 'o ue to shear

stress (,)

(ii) A re%tan&u#ar 'o -00 mm #on&? 100 mm wie an -0 mm thi%k

is su'9e%te to a shear stress o$ 0 MPa !etermine the strain

ener& store in the 'o Take . = - 108./mm2 (10)