Double Skinned Steel Tubular Columns

8/19/2019 Double Skinned Steel Tubular Columns

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IC-RICE 2013 – PDACEG – Karnataka - India

International Conference on

Recent Innovations in Civil Engineering From !cto"er 2# to !cto"er 2$% 2013

Organised by P.D.A. College of Engineering, Gulbarga

“EXPERIME!A" I#E$!IGA!IO O DO%&"E $'IED $!EE"!%&%"AR (D$$!) CO"%M$ $%&*EC!ED !O MOO!OIC "OADIG+

&r'Dars(an'&'K 1 & Dr.N.S.Kumar 2

1 Post Graduate Student –Structural Engineering,

2 Professor & Director (R&D-Ciil Engg.,!

De"artment of Ciil Engineering, G#ousia College of Engineering, Ramanagara,, Karnata$a,

%ndia.

[email protected] / [email protected]

$%MMAR In t(is Dissertation% E)*eri+ental ,ork Analsis of ce+ent +ortar-steel

do."le-skin t.".lar +e+"er is carried o.t% ,it( t(e e+*(asis "eing on its *otential as ke lateral

and vertical load-resisting +e+"ers in str.ct.res located in seis+icall active regions' In t(is

ne, str.ct.ral +e+"er% t(e t,o constit.ent +aterials are o*ti+all co+"ined t(e o.ter and

inner t."e is +ade of steel% and t(e s*ace in-"et,een is filled ,it( ce+ent +ortar' /(ese

+e+"ers are (ig(l .sef.l ,(en t(e are .sed as col.+ns' /(ese +e+"ers are +onotonicallloaded to t(eir .lti+ate load to st.d t(e "e(avior of D/ .nder increasing D ratio and

kee*ing /(ickness constant' ence% t(is +e+"er can "e referred to Do."le-kin /.".lar

Col.+n 4D/C5% In t(is e)*eri+ental *rogra++e% #$ sa+*les (ave "een tested'

ere% an atte+*t is +ade to st.d t(e strengt( of totall #$ s*eci+ens of t(e follo,ing

t(ree +odels' As *er I$- /012342 (Reaffirmed 2330)1!5ird re6rin7, February 23381Indian

$7andard 9ode of 6ra97i9e for 6re6ara7ion and use of masonry mor7ars % for +asonr in

".ildings s."6ect to vi"ration of +ac(iner% t(e grade of +ortar s(all not "e less t(an && 3

4Cla.se $'1'75' ence% in t(is dissertation ,ork +ortar grade of 13% 17 and 1# (as "een

selected as infill to fill t(e ga* "et,een o.ter and inner t."es' i'e' Do."le kinned /."es' Eac(

+odel is of t(ree sets' !ne set consists of 13 ratio &ortar and re+aining t,o consists of 17 and

1# ratio &ortar res*ectivel ,(ic( is filled in "et,een t(e ga*s of steel t."es of different

mailto:[email protected]:[email protected]:[email protected]:[email protected]


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lengt(s and t(ickness' /(e lengt(s of t(e s*eci+ens .sed for st.d are 3#0++% 7#0++ and

##0++ of varing t(ickness 2'8++% 3'2++ and 7'0++'

Res.lts (ave "een anal9ed .sing +ost recent soft tool Artificial :e.ral :et,orks

;A::a*anese first and e+*loed in t(e constr.ction

of +.lti-storied ".ildings effectivel' :o,% t(e analsis and Design of t(ese D/ Col.+ns

(ave fo.nd *lace even in Codes and *ecifications' It (as "een envisaged to st.d strengt(%

stiffness and ".ckling c(aracteristics " *roviding fl.tes to steel t."e of col.+ns ,(ic( en(ances

aest(esis of col.+ns' Also% a fl.ted col.+n en(ances t(e strengt( and also stiffness as t(e

s.rface area of steel s(eet and +o+ent of inertia of t(e col.+n increases' /(e advantage of steel

+e+"ers (aving (ig( tensile strengt( and d.ctilit and concrete +e+"ers (aving "etter

co+*ressive strengt( (ave "een "etter +ade .se as a co+*osite +e+"er' ence% it (as "eenenvisaged to c(eck ,(et(er s.c( a col.+ns ,o.ld act as a slender col.+n' Researc( (as "een in

*rogress aro.nd t(e ,orld on e)*eri+ental and analtical st.dies on do."le skinned teel

/.".lar Col.+ns for +ore t(an fo.r decades' ."stantial contri".tion (as "een +ade since t(en

in .nderstanding t(e "e(avior of D/ col.+ns and to arrive at a design *roced.re' ?.ite fe,

co.ntries (ave incor*orated t(e design *roced.re in t(eir res*ective codes also' &ost of t(e

researc(ers (ave considered t(e contri".tion of geo+etric *ro*erties like s(a*e% D ratio% tD

ratio% "o.ndar conditions% strengt( of +aterials and t(e loading conditions' It (as "een fo.nd

t(at generall t(e fail.re occ.rs " eit(er local ".ckling or ield fail.re' It (as "een fo.nd t(at

E.ro code gives a "etter design +et(od ,(ic( ields val.es nearer to e)*eri+ental val.es'


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Col.+ns are considered as critical +e+"ers in +o+ent-resisting str.ct.ral sste+s'

/(eir fail.re +a lead to a *artial or even a total colla*se of t(e ,(ole str.ct.re' /(erefore% it is

i+*ortant to i+*rove t(e d.ctile defor+ation ca*acit and energ dissi*ation ca*acit of

col.+ns so t(at t(e entire str.ct.re can end.re severe gro.nd +otions and dissi*ate a

considera"le a+o.nt of seis+ic energ' In recent ears% do."le skinned steel t."es 4D/s5 (ave

"eco+e increasingl *o*.lar as col.+ns in "raced and .n"raced fra+es% as t(e (ave t(e

advantages of d.ctile "e(avior as a res.lt of confine+ent to concrete " t(e steel t."e and

delaed local ".ckling of t(e steel t."e d.e to t(e s.**ort fro+ concrete% i+*roved da+*ing

"e(avior in co+*arison to traditional steel fra+es% ease for constr.ction as t(e steel t."e serves

also as t(e *er+anent for+% and a (ig( strengt(-to-,eig(t ratio' Do."le kinned steel t."e

4D/5 col.+ns co+"ine t(e advantages of d.ctilit% generall associated ,it( steel str.ct.res%

,it( t(e stiffness of a concrete str.ct.ral sste+' /(e advantages of t(e concrete-filled steel t."e

col.+n over ot(er co+*osite sste+s incl.de /(e steel t."e *rovides for+,ork for t(e

concrete% t(e concrete *rolongs local ".ckling of t(e steel t."e ,all% t(e t."e *ro(i"its e)cessive

concrete s*alling% and co+*osite col.+ns add significant stiffness to a fra+e co+*ared to +ore

traditional steel fra+e constr.ction' @(ile +an advantages e)ist% t(e .se of D/s in ".ilding

constr.ction (as "een li+ited% in *art% to a lack of constr.ction e)*erience% a lack of

.nderstanding of t(e design *rovisions and t(e co+*le)it of connection detailing'

Conse.entl% a 6oint ,as needed t(at co.ld .tili9e t(e favora"le strengt( and stiffness

c(aracteristics of t(e concrete-filled t."e col.+n et "e constr.cti"le' /(e inner void red.ces t(e

col.+n ,eig(t ,it(o.t significantl affecting t(e "ending rigidit of t(e section and allo,s t(e

eas *assage of service d.cts ".t in t(is e)*eri+ent ce+ent +ortar (as "een .sed instead of

concrete d.e to ver less ga* "et,een t(e t,o t."es'

Big.re1'do."le skinned col.+ns


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/(e e.ation can

"e generated to find

t(e lti+ate load carring ca*acit' A)ial s(ortening .lti+ate

stress carring ca*acit of t(e col.+n' Prediction of CC can "e done .sing :ER! ol.tions

Artificial :e.ral :et,ork /ool o) 4&A/ la"5'

. AR!IFICIA" E%RA" E!:OR'

!ne ,a of incl.ding s*eci+en irreg.larities in t(e +odel is to .se t(e res.lts of t(e

availa"le e)*eri+ents to *redict t(e "e(avior of co+*osite t."es s."6ected to different loading'

Artificial :e.ral :et,ork 4A::5 is a tec(ni.e t(at .ses e)isting e)*eri+ental data to *redict

t(e "e(avior of t(e sa+e +aterial .nder different testing conditions'

In t(e c.rrent ,ork% t(e *rediction of t(e load-carring ca*acities for a)iall Cclic

loaded Circ.lar .are co+*osite t."es is eval.ated .sing A::' /o test t(e validit of .sing

A:: in deter+ining t(e cr.s(ing "e(avior of t(ese t."es% t(e st.d ,ill co+*are t(e *redictions

o"tained to t(e e)*eri+ental res.lts .sing t(e ne.ral net,ork tool in &A/A v$'12 4R2011a5'

A:: (ave e+erged as a .sef.l conce*t fro+ t(e field of artificial intelligence% and (as

"een .sed s.ccessf.ll over t(e *ast decade in +odeling engineering *ro"le+s in general% and

s*ecificall t(ose relating to t(e +ec(anis+ "e(avior of co+*osite +aterials'

A:: generall consists of a n.+"er of laers t(e laer ,(ere t(e *atterns are a**lied is

called in*.t laer' /(is laer co.ld t*icall incl.de t(e *ro*erties of t(e co+*osite +aterial

.nder consideration% its la.*% t(e a**lied load% t(e t."e as*ect ratio etc' /(e laer ,(ere t(e

o.t*.t is o"tained is t(e o.t*.t laer ,(ic( co.ld% for e)a+*le% contain t(e res.lting defor+ation

of t(is t."e .nder t(e given loading conditions' In addition% t(ere +a "e one or +ore laers

"et,een t(e in*.t and o.t*.t laers called (idden laers% ,(ic( are so na+ed "eca.se t(eir

o.t*.ts are not directl o"serva"le' /(e addition of (idden laers ena"les t(e net,ork to e)tract


5/16

(ig(-order statistics ,(ic( are *artic.larl val.a"le ,(en t(e si9e of t(e in*.t is ver large'

:e.rons in eac( laer are interconnected to *receding and s."se.ent laer ne.rons ,it( eac(

interconnection (aving an associated ,eig(t'

A training algorit(+ is co++onl .sed to iterativel +ini+i9e a cost f.nction ,it(

res*ect to t(e interconnection ,eig(ts and ne.ron t(res(olds' /(e training *rocess is ter+inated

eit(er ,(en t(e &ean .are Error 4&E5 "et,een t(e o"served data and t(e A:: o.tco+es for

all ele+ents in t(e training set (as reac(ed a *re-s*ecified t(res(old or after t(e co+*letion of a

*re-s*ecified n.+"er of learning e*oc(s'

. 'olmogoro;


6/16

Big.re2 lock diagra+ of feed for,ard net,ork

Given an f.nction

& ' R % mn =→ 54% φ φ

% ,(ere I is t(e closed .nit interval ;0%1


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Big.re3':e.ron +odel

tan-sig+oid transfer f.nction tansig as s(o,n in fig.re2' ig+oid o.t*.t ne.rons are often

.sed for *attern recognition *ro"le+s% ,(ile linear o.t*.t ne.rons are .sed for f.nction fitting

*ro"le+s' /(e linear transfer f.nction *.relin as s(o,n in fig.re2'

.? !rain 75e e7=or>

!nce t(e net,ork ,eig(ts and "iases are initiali9ed% t(e net,ork is read for training' /(e

+.ltilaer feedfor,ard net,ork can "e trained for f.nction a**ro)i+ation 4nonlinear regression5

or *attern recognition' /(e training *rocess re.ires a set of e)a+*les of *ro*er net,ork "e(avior

net,ork in*.ts * and target o.t*.ts t'

/(e *rocess of training a ne.ral net,ork involves t.ning t(e val.es of t(e ,eig(ts and

"iases of t(e net,ork to o*ti+i9e net,ork *erfor+ance% as defined " t(e net,ork *erfor+ance

f.nction net'*erfor+Bcn' /(e defa.lt *erfor+ance f.nction for feedfor,ard net,orks is +ean

s.are error +set(e average s.ared error "et,een t(e net,ork o.t*.ts a and t(e target o.t*.ts

t' It is defined as follo,s

/(ere are t,o different ,as in ,(ic( training can "e i+*le+ented incremental mode and

(atc# mode' In incre+ental +ode% t(e gradient is co+*.ted and t(e ,eig(ts are .*dated after eac(

in*.t is a**lied to t(e net,ork' In "atc( +ode% all t(e in*.ts in t(e training set are a**lied to t(e

net,ork "efore t(e ,eig(ts are .*dated' /(is c(a*ter descri"es "atc( +ode training ,it( t(e trainco++and' Incre+ental training ,it( t(e ada*t co++and is disc.ssed in Incre+ental /raining ,it(

ada*t and in Ada*tive Bilters and Ada*tive /raining' Bor +ost *ro"le+s% ,(en .sing t(e :e.ral

:et,ork /ool"o) soft,are% "atc( training is significantl faster and *rod.ces s+aller errors t(an

incre+ental training'Bor training +.ltilaer feedfor,ard net,orks% an standard n.+erical

o*ti+i9ation algorit(+ can "e .sed to o*ti+i9e t(e *erfor+ance f.nction% ".t t(ere are a fe, ke

ones t(at (ave s(o,n e)cellent *erfor+ance for ne.ral net,ork training'

/(ese o*ti+i9ation +et(ods .se eit(er t(e gradient of t(e net,ork *erfor+ance ,it(

res*ect to t(e net,ork ,eig(ts% or t(e >aco"ian of t(e net,ork errors ,it( res*ect to t(e ,eig(ts'


8/16

/(e gradient and t(e >aco"ian are calc.lated .sing a tec(ni.e called t(e "ack*ro*agation

algorit(+% ,(ic( involves *erfor+ing co+*.tations "ack,ard t(ro.g( t(e net,ork' /(e

"ack*ro*agation co+*.tation is derived .sing t(e c(ain r.le of calc.l.s'

./ e7=or> Pro6er7ies

/(e net,ork t*e is feed for,ard "ack*ro*agation' /(e training f.nction is leven"erg-

+ar.ardt algorit(+' /(e *erfor+ance f.nction is +ean s.are error' /(e transfer f.nction is

tan-sig+oidal and *.relin4Big'75'

8. :or> Flo=

/(e ,ork flo, for t(e general ne.ral net,ork design *rocess (as seven *ri+ar ste*s

1' Collect data

2' Create t(e net,ork 3' Config.re t(e net,ork

7' Initiali9e t(e ,eig(ts and "iases

#' /rain t(e net,ork 8' Jalidate t(e net,ork 4*ost-training analsis5

$' se t(e net,ork

?. E@%IPME!$ EXPERIME!A" PROGRAM

C.tter %Grinding +ac(ine %,eig(ing +ac(ine /a+*ing rod 200ton Cclic oading

&ac(ine to cond.ct t(e +onotonic loading tests on all *eci+ens

Big.re7' 200/ +onotonic /esting &ac(ine


9/16

!es7s Analysis- Bor Eac( &odel% fro+ ever test follo,ing reading ,ill recorded

oad variation fro+ load ga.ge in K:% Deflection in ++ tress in :++2

Gra65i9al Analysis- Grade vs load% ld vs load

?.2 !abula7ion of resul7s of s6e9imens.

grade of

+ortar

section *ro*erties 4++5

+aterial

*ro*ertie

s

.ti+ate a)ial

load

4e)*eri+ental

5

deflectio

n 4++5

D / f c f

13 33'$ 2'8 3#0 $'0 310 123 727

72'7 2'8 3#0 $'0 310 133 72#'23

72'7 2'8 3#0 $'0 310 13= #$'$7

33'$ 2'8 7#0 $'0 310 111 #3#'7

72'2 2'8 7#0 $'0 310 127 #31'8

72'7 2'8 7#0 $'0 310 13# #30'$7

33'$ 2'8 ##0 $'0 310 107 831'#

72'7 2'8 ##0 $'0 310 11= 827'01

72'7 2'8 ##0 $'0 310 120 2=2'

33'$ 3'2 3#0 $'0 310 18# 7='23

72'7 3'2 3#0 $'0 310 21 772'18

72'7 3'2 3#0 $'0 310 1= 73$'7#

33'$ 3'2 7#0 $'0 310 1#0 11='12

72'2 3'2 7#0 $'0 310 21# 7$'8

72'7 3'2 7#0 $'0 310 1=3 830'$8

33'$ 3'2 ##0 $'0 310 11# #8$'#8

72'7 3'2 ##0 $'0 310 200 3#7'18


10/16

72'7 3'2 ##0 $'0 310 1= 7$'77

72'7 7'0 3#0 $'0 310 273 711'27

17

33'$ 2'8 3#0 8'2 310 112 733'=7

72'7 2'8 3#0 8'2 310 12= 730'83

72'7 2'8 3#0 8'2 310 137 731'$8

33'$ 2'8 7#0 8'2 310 10# 711'#8

72'2 2'8 7#0 8'2 310 121 #11'33

72'7 2'8 7#0 8'2 310 131 7='37

33'$ 2'8 ##0 8'2 310 = #73'1$

72'7 2'8 ##0 8'2 310 11 811'23

72'7 2'8 ##0 8'2 310 120 2$$'3

33'$ 3'2 3#0 8'2 310 1$3 732'01

72'7 3'2 3#0 8'2 310 217 731'88

72'7 3'2 3#0 8'2 310 13 732'33

33'$ 3'2 7#0 8'2 310 188 133'$8

72'2 3'2 7#0 8'2 310 20$ 7$'3

72'7 3'2 7#0 8'2 310 1$8 #8$'##

33'$ 3'2 ##0 8'2 310 1#= 837'01

72'7 3'2 ##0 8'2 310 1=7 37$'$$

72'7 3'2 ##0 8'2 310 1$1 7$'0=

72'7 7'0 3#0 8'2 310 21= 723'=

1# 33'$ 2'8 3#0 #'3 310 118 731'07

72'7 2'8 3#0 #'3 310 173 72='$

72'7 2'8 3#0 #'3 310 17$ 738'#3

33'$ 2'8 7#0 #'3 310 110 702'2#

72'2 2'8 7#0 #'3 310 11 7=8'#7


11/16

72'7 2'8 7#0 #'3 310 128 7$$'13

33'$ 2'8 ##0 #'3 310 =7 #11'07

72'7 2'8 ##0 #'3 310 113 #$'38

72'7 2'8 ##0 #'3 310 11$ 73#

33'$ 3'2 3#0 #'3 310 1# 737'2$

72'7 3'2 3#0 #'3 310 21$ 730'08

72'7 3'2 3#0 #'3 310 1$$ 27'7#

33'$ 3'2 7#0 #'3 310 172 10='3

72'2 3'2 7#0 #'3 310 1=1 7#8'$8

72'7 3'2 7#0 #'3 310 187 #23'23

33'$ 3'2 ##0 #'3 310 123 7='37

72'7 3'2 ##0 #'3 310 13 3$#'#

72'7 3'2 ##0 #'3 310 1#$ 711'77

72'7 7'0 3#0 #'3 310 21# 711'8#

?.2.- 6lo7 for .Bmm 75i9>, 8/0mm leng75

GRADE

(X)

"OAD

(y)

13 123

13 13313 13=

17 112

17 12=

17 137

1# 118

1# 173

1# 17$


12/16

020406080100120140160

GRADE V/S LOAD

LOAD

6lo7 for .Bmm 75i9>, ?/0mm leng75

020406080

100120140160

GRADE V/S LOAD

LOAD

Plo7 for .Bmm 75i9>, ?/0mm leng75

?.2.8 Plo7 for "D ;s "oad

GRAD

E (X)

"OAD

()

13 111

13 127

13 13#

17 10#

17 121

17 131

1# 110

1# 11

1# 128


13/16

Plo7 for 2-8 ra7io, .B mm 75i9>

lengt

( D ratio

!AD

in K:

3#0 10'3 123

13

ratio

% 2'8

++

t(ic

k

3#0 '2# 133

3#0 '2# 13=

7#0 13'3# 111

7#0 10'81 127

7#0 10'81 13#

##0 18'32 107

##0 12'=$ 11=

##0 12'=$ 120

0

50

100

150

L/D v/s LOAD

L/D v/s LOAd

L/D ratio

Load (KN)

Plo7 for 2-? ra7io, .B mm 75i9>


14/16

lengt

( D ratio

!AD in

K:

3#0 10'3 112

17

ratio%

2'8+

+

t(ick

3#0 '2# 12=

3#0 '2# 137

7#0 13'3# 10#

7#0 10'81 121

7#0 10'81 131

##0 18'32 =

##0 12'=$ 11

##0 12'=$ 120

020406080

100120140160

L/D v/s LOAD

L/D v/s LOAd

L/D ratio

Load (KN)

COC"%$IO$


15/16

As t(e lengt( of t(e D/ increases% t(e .lti+ate a)ial strengt( decreases'

As t(e ,all t(ickness of "ot( inner and o.ter t."e is greater% it can ,it( resist +ore a)ial

load' ig(er t(e total cross sectional area of D/% "etter t(e .lti+ate a)ial strengt('

/(e infilled +aterial ce+ent +ortar also acts as fire resistance'

/(e steel t.".lar col.+n gives good aest(etic a**earance'

linear "e(avior till ielding ,as o"served along ,it( non-linear "e(avior "eond ielding%

ess ".ckling d.e to inner core'

Res.lts o"tained fro+ A:: +odel develo*ed +atc(ed ,ell ,it( e)*eri+ental val.es 4,it(

a deviation of not +ore t(an #L -10L5

REFERECE$

;1


16/16

arc(itect.re% 9(e 6iang .niversit% (ang 9(o.% 31002$% c(ina 4teng et al' 20025' aci str.ct.ral

6o.rnal% vol'=% no'7% **'7#1-781'

;2o.rnal of Constr.ctional teel Researc(% Jol'82% :o'$% 831-878'

Documents

Double Skinned Steel Tubular Columns