1. An exhaust exhaust fan, having a small small unbalance, unbalance, weights 800 N an an !"e#ates at at a s"ee !f
$00 #"m% &t is esi#e t! limit the #es"!nse t! a t#ansmissibilit' !f (%) as the fan "asses th#!ugh #es!nance u#ing sta#t*u"% &n aiti!n, an is!lati!n !f +0 "e#cent is t! be achieve at the !"e#ating s"ee !f the fan% Design a suitable is!lat!# f!# the fan% -0 ma#.s/
!. An ai# c!m"#ess!# !f mass )00 .g has an unbalance !f 0%)0 .g*m an !"e#ates at a
s"ee !f 00 #"m% The c!m"#ess!# is t! be m!unte !n !ne !f the f!ll!wing m!untings1 2a3 an is!lat!# c!nsisting !f a s"#ing with negligible am"ing, an 2b3 a sh!c. abs!#be# having a am"ing #ati! !f 0%- an negligible stiffness% 4elect a suitable m!unting an s"ecif' the esign etails b' c!nsie#ing the static eflecti!n !f the c!m"#ess!#, the t#ansmissi!n #ati!, an the am"litue !f vib#ati!n !f the c!m"#ess!#% -0 ma#.s/
1
Tutorial Exercise-11
MDB3093: Vibrations
". The a#matu#e !f a va#iable*s"ee elect#ic m!t!#, !f mass (00 .g, has an unbalance
ue t! manufactu#ing e##!#s% The m!t!# is m!unte !n an is!lat!# having a stiffness !f -0 .N5m an a ash"!t having a am"ing #ati! !f 0%-)% 2a3 6in the s"ee #ange !ve# which the am"litue !f the fluctuating f!#ce t#ansmitte t! the f!unati!n will be la#ge# than the exciting f!#ce% 2b3 6in the s"ee #ange !ve# which the t#ansmitte f!#ce am"litue will be less than -0 "e#cent !f the exciting f!#ce am"litue% -0 ma#.s/
#.
A washing machine !f mass )0 .g !"e#ates at -(00 #"m% 6in the maximum stiffness !f an is!lat!# that "#!vies 7) "e#cent is!lati!n% Assume that the am"ing #ati! !f the is!lat!# is 7 "e#cent% -0 ma#.s/
$.
A iesel engine !f mass 00 .g an !"e#ating s"ee -800 #"m is f!un t! have a #!tating unbalance !f - .g*m% &t is t! be installe !n the fl!!# !f an inust#ial "lant f!# "u#"!ses !f eme#genc' "!we# gene#ati!n% The maximum "e#missible f!#ce that can be t#ansmitte t! the fl!!# is 8000 N an the !nl' t'"e !f is!lat!# available has a stiffness !f - MN5m an a am"ing #ati! !f ) "e#cent% &nvestigate "!ssible s!luti!ns t! the "#!blem% -0 ma#.s/
