chuong 4- tin học xd

Phn II- Phn mm SAP2000

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Chng 4 Tnh ton cc kt cu tm, v

1. khi nim chung

Tm v v l cc kt cu ph bin trong nhiu cng trnh xy dng dng lm mi che,

sn, tng, xilo, b cha. . .Trong cc phn mm tnh kt cu, cc phn t tm, v c m hnh ha qua cc mt phng trung bnh ca n. Ty theo s lm vic m n c th coi

l tm chu un, mng hay v.

Mi phn t tm, v c th m t qua phn t tam gic (3 nt) hoc phn t t gic (4 nt) ca mt phng trung bnh v c 6 mt(mt trn, mt di v 4 mt cnh) nh cc hnh v

sau:

Hnh 4.1 Phn t 4 nt Hnh 4.2 Phn t 3 nt

Hnh 4.3 Phn t v h ta ring

Khi chia li phn t phi ch cc yu cu hnh hc :

PDF created with pdfFactory Pro trial version www.pdffactory.com

ng dng Tin hc trong Thit k cng trnh

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- Cc gc ca phn t t 45-135o

- T s gia hai cnh di v ngn khng nn qu ln nn 4( hai cnh bng nhau l tt nht).

- Li chia th hay mau ph thuc vo s thay i hnh hc, ti trng v yu cu v chnh xc ca kt cu, tuy nhin cc phn t phi ni tip nhau, khng c nt trn cnh ca phn t (hnh 4.4).

- Vi phn t 4 nt, khng nht thit c 4 nt phi trn cng mt mt phng, gc lch ca mt phng khng qu 15o

Hnh 4.4 Chia phn t s dng phn t 4 nt

1.1. Loi ca phn t c th l mt trong cc loi:

- Phn t mng ( Membrane ) ch chu ko, nn => khng c chuyn v thng vung gc vi mt phng v xoay ngoi mt phng ( c 3 bc t do Ux, Uy, Rz).

- Phn t tm ( Plate- Thick Plate ) un thun tu => khng c chuyn v thng theo hai phng trong mt phng v xoay trong mt phng (c 3 bc t do Uz, Rx, Ry)

- Phn t v tng qut ( Shell- Area ) : chu ko,nn,un ,c 6 bc t do (Ux, Uy, Uz, Rx, Ry, Rz).

1.2. H ta a phng

H trc to ring k hiu 1-2-3 trong trc 1 (mu ), trc 2(mu trng) nm trong

mt phng phn t, cn trc 3( xanh c ban) lun vung gc vi b mt phng phn t c

hng dng theo chiu tin ca ci vn nt chai khi chiu ca cc nt 1-2-3-4 l thun kim ng h.



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Hnh 4.5 Gc ta phn t so vi hng mc nh

Hng mc nh ca h trc ta a phng l do chng trnh t ng xc nh khi to ra phn t, ph thuc vo quan h gi trc 3 v trc Z h Global. V d vi cc phn t

nm ngang, trc 1,2 nm trong mt phng X,Y cn trc 3 trng vi Z. Vi cc phn t

thng ng, trc 3 c chiu ca X hoc Y (xem hnh 4.1). Khi nim v gc ta phn t Area cng ging nh phn t thanh.

Trn hnh 4.5 minh ha s tng quan gia gc ta phn t so vi mc nh khi khai

bo gc ta phn t ln lt l 45o, 90o, 0o v -90o vi cc phn t hng 1,2,3,4 tnh t trn xung di. Ch trc 3 lun hng ra pha ngoi i vi mi phn t.

1.3. Vt liu :

- Trc hng ( Orthotropic ) : cc thnh phn bin dng ca 1 hng khc hai hng kia do vt cc gi tr ca mun n hi E, h s poisson, m un trt c gi tr theo

3 phng khc nhau.

- ng hng ( Isotropic) : bin dng theo cc hng ging nhau.

- Gc vt liu : gc ca hng chun ang nh ngha vi hng lm vic thc, mc nh bng 0.

1.4. Ti trng

TI trng trn phn t tm v bao gm cc loi sau :



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1.4.1. Ti trng bn thn

Tc dng ln mi phn t, l TT phn b u ln mt phng ca phn t, c gi tr = W. t

(W l trng lng ring v t chiu dy phn t )

1.4.2. Ti trng phn b u

Thng tc dng ln mt phng trung bnh, c hng bt k theo cc h trc ang dng (h global hoc h ta ring PT). Vi nhng phin bn SAP mi, ti trng phn b trn

phn t c th khng u v tc dng ln mt hoc nhiu mt trong s 6 mt ca phn t.

Cc ti trng t trn phn t u c qui i v h ta ring phn t v cng vi nhau. Lc tng cng trn mi hng s nhn vi din tch ca mt phng trung bnh v

chia u cho cc nt trong phn t.

Hnh 4.6 Ti trng phn b u t trn din tch hnh chiu ca mt phng trung bnh

- Gravity : TT c hng trng lc( -Z ) ,c th tc dng ln mt s phn t v c phng bt k

- Global Projection : TT c hng hnh chiu ca lc ln cc trc.

1.4.3. Ti trng p lc

- V tng qut c th tc dng ln mt mt phng bt k ca 6 mt phn t.

- C hng vung gc vi mt m lc tc dng ln ( theo phng php tuyn ca cc mt). Nu nhp d liu vo theo giao din ho th ch khai bo vi TT tc dng ln mt 5-6 (b mt phn t) & c chiu dng theo trc +3.

1.5. Cc thnh phn ni lc ca v

Phng php phn t hu hn dng m hnh chuyn v, do vy ng sut v ni lc s

khng lin tc gia cc phn t. Trong SAP2000 kt qu ni lc hay ng sut c tnh ti 4 im tch phn Gauss, sau ngoi suy ra cc im nt. Cc gi tr ng sut v ni lc



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ti mt nt chung ca nhiu phn t khc nhau s khc nhau. Trong khi hin th kt qu n c ni suy v lm trn cho thit k. Mi di mu c 2 gi tr bin trn thang mu.

Cc i lng ca ni lc bao gm :

- Lc mng ( ng lc mng - lc dc ) F11 = s 11. A, F22 theo cc phng trc 1 v trc 2 ca h to ring

- Lc ct mng : F12 = t 12. A

- Mmen un : M11 = t. s 11. A v M22 = t.s 22. A ( t chiu dy Pt, A din tch, s11 ng sut php)

- Mmen xon : M12 = t. s 12. A

- Lc ct : V13 = t 12. A ; V23 = t 23

M11 : mmen un trong mt phng 23 ; M22 : mmen un trong mt phng 13

M12 : mmen un xon ; FVM, SVM : lc v ng sut theo phng Ven

Mises

Hnh 4.7 bn tri minh ha cho ng sut v cc lc mng. Hnh 4.7 bn phi minh ha

cho m men xon v un ca tm (Plate)

Hnh 4.7 Cc thnh phn ni lc phn t Area v qui c

2. trnh t thit s tnh cho kt cu tm -v

2.1. Thit lp s hnh hc

2.1.1. To lp kt cu ban u

2.1.1.1. Gi cc kt cu t th vin mu:

File New Model s hin hp thoi (hnh 4.8).



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Trong hp thoi ny cc kt cu lin quan n tm v gm cc nhm: Wall, Flat Slab,

Shells, Staircases, Storage Structure. . . thit lp mt dng v c th, li truy cp tip cc thnh phn bn trong ca nhm. V d t Shells ta c cc dng trong hnh 4.9; t

Storage Structure c mt trong cc dng nh hnh 4.10.

Hnh 4.8 Hnh 4.9

Sau khi chn loi mt loi v, SAP s yu cu bn a vo tip cc tham s cn thit .

xem c th cc thng s chn vo Paramatric Definition (Hnh 4.10 Hnh 4.11)

Hnh 4.10 Hnh 4.11

2.1.1.2. Thit lp s qua h li ph tr

xy dng s hnh hc ca mt kt cu tm, v bng h li, ngi dng s thit lp

h li Decac hoc tr sao cho d dng to nn cc phn t trn , sau v cc phn t, bin i c s mong mun. Trong chng 3 trnh by v h li trong h ta

cc (Cartesian), chng ny s ni k hn v h ta tr (Cylindrical)

thit lp h ta tr, cn khai bo cc tham s :

- Number of Grid Line : S cc ng li



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+ along Radius : dc theo bn knh (s lng cc ng trn ng tm)

+ along Theta: s lng cc ng chia theo ng kinh tuyn

+ along Z : cc khong chia theo phng Z

- Grid Spacing: khong cch gia cc i lng khai bo trn

+ along Radius : KC gia cc ng trn ( v tuyn)

+ along Theta: ln mt gc chia

+ along Z: chiu co cc khong chia theo phng Z.

H li trong ta tr c th thm, bt, xa, di chuyn nh trong h ta cc

V d :

Hnh 4.12 khai bo tham s cho h ta tr v c kt qu trn hnh 4.13 :

2.2. Khai bo cc loi tit din

Define Area sections Add New section Area section Data.

- Section name: nhp tn tit din.

- Metarial name: chn vt liu.

- Area type:

+ Shell: phn t v

+ Plane - Phn t kiu bin dng phng hoc ng sut phng

Hnh 4.12 Hnh 4.13



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+ Axisymmetric - Phn t i xng trc( Asolid)

- Thickness: dy.

- Trong type chn loi phn t shell (xem phn 1.1). Nu khng chc chn rng

lc ct trong shell l rt b ta chn vo thick plate.

Lu :

dy phn t (Thickness) : mc nh dy mng (t1) v dy un (t2) nh nhau. t1 c dng tnh cng chng ko nn ca phn t; t2 tnh cng chng un. Ti trng bn thn c tnh

theo t1

Khi khai bo sn vt liu btng hay thp: t1 = t2. Trng hp m phng cho mt nhn, gp t1 t2.

Hnh 4.14

- Gn tit din

+ Chn tit din

+ Assign Area section Chn trong section OK.

2.3. V cc phn t shell

v phn t Area(Shell) c th dng mt trong ba cch sau:

+ V phn t hnh ch nht da vo 2 im gc trn ng cho

+ V nhanh phn t bng cch chn vo 1 im bt k trong li.

+ V phn t a gic bng cch xc nh 4 im.

Trong qu trnh bin i s c th s dng cc lnh trong Edit nh trnh by trong

chng 2 v 3.

2.3.1. Chia phn t

m bo m hnh ng kt cu trong a s cc trng hp u phI chia phn t. Khi chia phn t cn ch :

+ Cc phn t shell v thanh phi cng chung cc nt khi lm vic ng thi.



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+ Cc phn t tm c kch thc khc nhau phi ch n cc im giao nhau (chia cc phn t phi lin tc, nu khng biu s khng lin tc, xem hnh 4.4).

Chn phn t

Menu Editmesh areas Mesh selected shellsl ( hnh 4.15). C 3 cch chia

- Nhp s khong chia theo 2 chiu ( mesh into, by)

+ Nu phn t shell thuc mt phng XY: Mesh into: chia theo phng X, by: chia theo phng Y.

Hnh 4.15

+ Nu phn t shell thuc mt phng XZ: Mesh into: chia theo phng X, by: chia theo phng Z

+ Nu phn t shell thuc mt phng YZ: Mesh into: chia theo phng Y, by: chia theo phng Z.

- Mesh using selected joints on edge: (hnh 4.16) chia phn t theo cc im trn cnh phn t

Hnh 4.16

Hnh 4.17

Chc nng ny thng c dng khi chia phn t trong kt cu dm sn: sau khi chia

phn t sn, ta thc hin chia phn t dm theo cc nt chia.

- Mesh at intersection with grids:(hnh 4.17) Chia phn t ti ch giao vi ng li.

2.4. Khai bo ti trng v gn

Trong phn khi nim chung v phn t Area(Shell) trn trnh by cc loi ti trng

c th tc ng ln phn t. Trong mc ny ch yu hng dn cc bc thao tc cho

mt s loi ti trng thng dng.

gn ti trng, ngi dng phi thc hin cc bc sau:

- Chn nhm phn t chu tc ng ca ti trng (bng cc kiu ca Select, tham kho chng 2).

- Chn loi ti trng cn gn trong hp thoi hnh 4.18



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Area Load Uniform( Gravity,Surface...)

- Khai bo cc tham s cn thit trong hp thoi

(xem phn khai bo v gn TT).

Hnh 4.18

Hnh 4.19

2.4.1. Ti trng bn thn : - Load Case Selfweigh( Mutiplier): nhp h s Selfweigh, h s ny p dng cho tt

c cc phn t trong m hnh. Mun SAP t ng tnh ti trng bn thn, h s ny

khi khc 0.

2.4.2. Ti trng phn b u trn din tch

Cch thc hin:

- Chn phn t

- AssignArea LoadsArea Uniform Loads(hnh 4.19)

- Load Case Name : chn tn trng hp ti trng mun t ti

- Load : a vo gi tr ti trng /din tch

- Direction : hng ti trng.

Hnh 4.20

Hng ca ti trng tc dng ln tng phn t ph thuc vo h to (tng th hoc a phng) v phng (Direction). Nu chn HT Global th c th chn 1 trong 8

phng ca Direction, cn chn Area Local th ch chn c mt trong ba phng

1,2,3.

- Nhn OK

2.4.3. Ti trng tp trung trn nt

Vi ti trng ti nt th cch khai bo v gn ging nhau vi mi loi phn t, gn ti trng vo Assign Joint Load (tham kho trong chng 2).

2.4.4. Ti trng nhit

K n s thay i nhit ca th trn v th di phn t.



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2.4.5. TT p lc ( Surface pressure)

Ti trng p lc lun c hng vung gc vi mt phng phn t. Vi phin bn SAP7, ti

trng p lc cho gn cho mt phng trung bnh ca phn t, chiu dng l chiu ca trc 3. Vi phin bn Sap9 tr i, ti trng p lc c th c gn cho c 6 mt phn t, chiu

dng ca ti trng l chiu hng vo mt phn t, chiu m i ra khi mt phn t.

Cch khai bo:

- Chn phn t.

- Assign/ shell static load/ pressure.

- Nu nhp p lc phn b u chn by element/ pressure v nhp gi tr lc

- Nu nhp p lc phn b khng u chn by joint pattern (nhp theo mu nh ngha trc)

+ pattern: chn pattern ( c nh ngha trc)

+ mutiplier: h s.

- Face: chn mt chu p lc ( xem hnh 4.1)

- OK

Ch :

+ Dng JP nn ring trong mt trng hp ti trng

+ Cc ti trng JP c th ch tc dng ln mt nhm phn t ( khng nht thit c kt cu )

+ Trong qu trnh khai bo mu JP, nhm nt nh du thuc cao h s nh hng n s chia ti trng trn , do vy khi gn ti trng cc nt trong min chu tc dng ca ti trng c cao khc vi h ban u, s ti trng s t phn

chia li trong min nh du .

Cch nh ngha pattern:

Pattern c nh ngha cho nt. Bn cht l gn

cho cc nt cc gi tr no . Da vo cc gi tr

ny ta nh ngha c tI trng phn b khng u trn mt tm shell.

Trong hnh bn mt tm c 4 nt l 1,2,3,4. Ta cn

gn ti trng phn b khng u. Vic trc tin ta phI nh ngha mt pattern. Theo pattern ny gi tr

ti cc nt l P1, P2, P3, P4 .Trnh t lm nh sau:



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- Chn cc nt.

- Menu assign/ joint pattern.

- Chn tn trong listbox pattern name.

- Trong Value = Ax + By + Cz+D: nhp cc gi tr A,B,C,D.

Value chnh l cc gi tr ti cc nt tng ng vi P1, P2, P3, P4 v ph thuc ta x,y,z. V vy A,B,C,D c xc nh t h phng trnh sau.

+++=

+++=

+++=

+++=

D4ZC4YB4XAP3

D3ZC3YB3XAP2

D2ZC2YB2XAP2

D1ZC1YB1XA1P

- Trong options:

+ Add to existing load: Thm vo ti trng c.

+ Replace existing load: Thay th ti trng c.

+ Delete existing load: Xa tI trng c.

- Cc la chn khc

+ Use all values: s dng tt c cc gi tr.

+ Zero negative values: cc gi tr m c gn bng khng.

+ Zero positive values: cc gi tr dng c gn bng khng

V d1:

Mt tm tng cao 6m, rng 6m, ngm ti t

nh hnh v

Yu cu: khai bo p lc thy tnh tc dng

nh hnh v (hnh 4.20), h s vt ti l 1.2.

Hng dn

Bc 1: To s hnh hc : S dng tm tng mu ca chng trnh. (FileNew Model Flat slab).

Bc 2: nh ngha tn pattern:

Hnh 4.21



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- Menu Define/ joint pattern.

- G tn THUYTINH vo pattern.

- Bm Add new pattern name

- Bm Add joint pattern.

- OK

Hnh 4.22

Buc 3: nh ngha gn joint pattern.

Chn tt c cc nt trn tm tng (joint pattern c gn cho nt ch khng phi cho phn t shell, bn phi chc chn cc nt c chn)

Menu assignjoint patternpattern data (hnh 4.22)

- Trong pattern name: chn THUYTINH

- Trong Value = Ax + By + Cz + D

+ Gi tr khng ph thuc ta X, Y nn A = B = 0

+ Ti Z = 0; Value = Cz + D = D = 5

+ Ti Z = 5;Value = Cz + D = 5C + 5 = 0

=>C = -1.

- Chn Zero negative values ( Xem hnh 4.22 v 4.23 )

Hnh 4.23 Hp thoi pattern Data

Gi tr ti cc nt th hin trong hnh 4.23

Sau khi thc hin bc gn pattern cho cc nt, ti cc nt xut hin cc gi tr. Cc gi tr

ny khng phi l gi tr lc. Lc ny phn t cha c gn ti trng.

Ch : nu trong bc 4 ta ch chn cc nt c ta z t 0 n 5 thay v chn tt c cc nt th c th chn use all values ta s c joint pattern nh hnh 4.24

Bc 4: Gn ti trng

- Chn cc phn t shell.

- AssignArea loads surface pressureShell pressure loads

- Chn TH TT trong Load Case Name



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- Chn n v trong Units.

- Chn By joint pattern

- Trong pattern chn pattern nh ngha bc 3 l THUYTINH.

- Trong multiplier nhp h s vt tI l 1.2.

- OK

Hnh 4.24

Sau khi nhp ti trng, gi tr lc c biu din nh hnh 4.26

Hnh 4.25 Nu chn use all value Hnh 4.26 Nu chn Zero negative values

Hnh 4.27 Biu p lc TT Hnh 4.28 S bin dng di p lc TT



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V d 2:

B nc trn v ch nht nh hnh 4.29

Hnh 4.29

- i vi thnh b: c th dng Joint Pattern, dng ti trng tam gic hoc dng Pressure trn phn t ,TT u trn tng on (hng TT theo php tuyn phn t).

- i vi y b: dng TT phn b u Uniform hng -Z

- i vi thnh c mt nghing, cong: dng JP chiu ln phng vung gc vi b mt y b, c gi tr = f*cosa (xt n thnh phn p lc thng, b qua thnh phn nm ngang) hoc = f*sina (xt n thnh phn p lc ngang, b qua thnh phn thng ng).

2.5. Cc khai bo khc

- Khai bo cc trng hp ti trng cho ton kt cu : Define Load Case

- Khai bo cc t hp ti trng : Define Combination

- Khai bo v gn cc nt c Lin kt ni t

- Khai bo v gn cc Nhm phn t : Group

Cc khai bo trn y v chc nng, cch dng cng ging nh trong phn t thanh, xin

tham kho thm trong chng 2 v 3.

i vi khung, tm cng lm vic theo s khng gian: Di tc dng ca ti trng ngang, cng trong mt phng ca h ln, bin dng nh. i vi kt cu nh cao tng,

c m hnh sn tuyt i cng ( Diaphragm ). Theo m hnh ny, 2 chuyn v thng trong

mt phng sn v mt chuyn v xoay ca cc nt trong mi mt phng l bng nhau, cc



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thnh phn khc c th khc nhau. cho kt cu lm vic ng v gim bt phng

trnh tnh ton, nn khai bo cc rng buc qua Constraint.

- Cch khai bo :

+ Chn cc nt trong cng mt phng. Ch c khai bo 1 constraint cho mi mt phng (khng c chn cc nt trong cc mt phng khc nhau hoc khai bo hai ln. . .) s gy li. Trong trng hp ny chn Null v lm li.

+ Vo Joint Constraint Add Diaphragm

+ Chn phng php tuyn ca mt phng (thng l Z)

- Ch :

+ Mi Diaphragm c h trc to ring l 1,2,3 (trong trc 3 lun vung gc vi mt phng)

+ C th loi b mt s nt trong tp chn bng Remove.

2.6. Mt s loi phn t khc

Trong phm vi gio trnh ny, cha gii thiu k cc loi phn t khc ngoi Frame v

Area( Shell), ch a ra mt s nt chnh ca phn t Plane, Asolid.

- Phn t PLANE : dng m t kt cu khi 2 chiu lm vic kiu bin dng phng v ng sut phng. N l phn t t 3-9 nt c chiu dy khng i, c mt phng phn

t lun song song vi mt trong cc mt phng ca h ta Global.

- Phn t Asolid : dng cho m hnh i xng trc chu ti trng xng. Phn t t 3-9 nt, c m hnh ho qua mt ct ngang hai chiu ca khi i xng trc 3

chiu...Trc i xng phi l mt trong cc trc ca Global. Trong loi phn t ny ch

xt n nh hhng ca chuyn v v ni lc theo phng dc trc.

3. phn tch, tnh ton

V c bn, cc chc nng v cch thao tc cho qu trnh phn tch,tnh ton, xem,hin, in

kt qu ca phn t Area cng ging phn t Frame. Trong chng 3 trnh by k

phn ny, y ch nhc li cc bc chnh v nhng phn khc bit ngi cho ngi dng tin theo di.

Qu trnh phn tch cn thc hin mt s bc sau:

- Kim tra m hnh kt cu

- La chn s tnh



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- Khai bo cc tham s tnh ton v la chn phng n xut kt qu (c th kt hp trong bc phn tch hoc phn xut kt qu)

- Tnh ton Phn tch

3.1. Kim tra m hnh kt cu :

y l mt bc khng bt buc nhng nn lm. Trong phn ny bao gm :

3.1.1. Kim tra s hnh hc

a kt cu v cc mt phng XZ,XY,YZ, dng chut phi nhn vo mt s phn t trong kt cu kim tra kch thc cc tng, cc nhp, mt s v tr c bit, nhng ni giao

nhau ca phn t, nhng ni xut hin nt.

3.1.2. Kim tra kch thc tit din

Trong phn ny ch :

- Kim tra kch thc cc tit din: Define Area SectionModify/Show Property.

- Kim tra gn tit din cha: View Set Display Option Area Section. Nhng phn t no cha gn s c tn cc tit din mc nh ca SAP l ASEC1 hoc SEC1.

- Kim tra s khng gian, dng khi (hnh 4.30): View Set Display Option Extrude view trnh nhng li do a vo cc kch thc khng hp l. V d, chiu dy tm cha khai bo, theo mc nh 1m. V d trn hnh 4.30 bn tri c

mt phn t ASEC1 cha khai bo, s c chiu dy bt hp l nh hnh 4.30 bn phi.

Hnh 4.30

3.1.3. Kim tra tng trng hp ti gn:

Trong phn ny, chng ta nn hin li cc ti trng ca tng trng hp (cho mi loi phn t) : Display Show Load Assign Chn Loi i tng (Area, Shell ). Trn hnh



256

4.31 hin cc ti trng gn cho sn khi cho hin theo gi tr (Uniform Load value) v

hnh 4.32 hin gi tr theo bng mu (Uniform Load Contour).

Hnh 4.31 Hnh 4.32

Ngoi cc bc kim tra trn, ngi dng c th kim tra thm cc thng s v vt liu, cc h s t hp, lin kt. . .

3.2. La chn s tnh : Analyse Set Analyse Option

Theo mc nh, SAP2000 cho php c 6 bc t do ca cc nt trong kt cu chuyn v

c, iu ny ch ph hp vi kt cu Space Frame v Shell. Trong trng hp m hnh

tnh ton l cc dng kt cu khc, ngi s dng phi chn v khai bo cho chng trnh qua 2 cch :

- Vi kt cu tm trong mt phng XY c th chn biu tng Grid Plan, vi dn khng gian, chn Space Truss; SAP t ng gn cc tham s ca Degree of fredom v nhn dng kt cu.

- Vi cc loi kt cu khng c trong cc kt cu mu ca SAP th ngi dng phi khai bo cc bc t do cho cc nt ca ton kt cu trong cc tham s ca Available DOFs.(hnh 4.33).

Hnh 4.33



257

3.3. Thc hin tnh ton : Analyse Set Analysis Case to Run

thc hin tnh ton (phn tch kt cu) vo Analyse Set Analysis Case to Runs la chn cc trng hp ( khai bo) cn tnh v trng thi Run trong Action sau

nhn Run now.

Hnh 4.34 Hnh 4.35

Chng trnh SAP2000 c th phn tch tnh v phn tch ng cc s kt cu, cho c

cc bi ton tuyn tnh v phi tuyn (tham kho thm phn ny chng 2,3).

4. Xem, xut kt qu

Kt qu ca SAP2000 c th xem trc tip trn mn hnh, in ra giy di dng ho

(cc biu , hnh v), cc tp d liu, cc bng cha d liu theo dng Text hoc xut ra

cc file c dng da trn cu trc c s d liu (Data base) ca Excel, Access, Word. xem kt qu thng thao tc mt hoc nhiu cc bc sau :

- Chn ca s hin (1- 4): Vo Option Window

- Chn cc i tng mun xem kt qu (thng thng l c kt cu)

- Chn trng hp hoc t hp mun xem

- Chn thnh phn d liu vo ( cc khai bo m hnh ) hoc kt qu tnh (chuyn v, ni lc...) mun hin .

- Chn loi tp tin :

+ D liu u vo : *. sdb(dng nh phn), *.$2k (dng text),

+ Kt qu : *.out, *.txt, *.xls, *.mdb

Sau y s trnh by cch hin (xem) kt qu theo nhng kiu khc nhau.



258

4.1. Kt qu trn ha - Display

xem kt qu trn ha, ngi s dng vo menu Display. Menu ny hin cc chc nng ca Display (hnh 4.36). Sau ty theo mun xem tip phn no, ngi dng vo

cc menu con m cc hp thoi, khai bo cc thng s c th chng trnh hin

cc biu , hnh v tng ng. V d hp thoi chn cc thnh phn ni lc hin kt qu (hnh 4.37).

Hnh 4.36 Hnh 4.37

4.1.1. Xem s hnh hc - Display Undeformation Shape

Vo chc nng ny, SAP s hin s kt cu khi cha bin dng (dng hnh hc ban

u ca kt cu).

4.1.2. Xem s ti trng ti trng : Display Show Load Assign

Sau khi thit lp v gn ti trng cho tng trng hp ti (Load Case), ngi dng c th

xem, kim tra li phn gn cho tng trng hp mnh thc hin c ng nh s hay

mun ca mnh hay khng. Mi ca s trn mn hnh v ng vi mt dng biu , SAP ch hin cho mt trng hp v mt loi ti trng (trn nt hoc trn phn t), ngi dng

c th khng hin hoc cho hin c gi tr ti trng gn.

Cc tham s cn khai bo khi hin mt s ti trng :

- Chn trng hp ti : chn mt tn trong danh sch ca Load name.



259

- Chn loi ti trng : Load Type, c th l mt trong cc loi :

- Joint - Frame - Area - Solid - Link

Chn cch hin s : Value -hin c hnh dng v gi tr; theo mc nh ch cho hnh

dng ca s ti trng. Trong trng hp chn hin TT trn phn t (frame, Area...) th SAP hin c cc TT trn phn t v trn cc nt.

- Chn H to khi hin s : Coordinate Sys.

4.1.3. Hin cc biu chuyn v : Display Show deformed Shape

hin cc biu chuyn v, thc hin cc thao tc:

- Chn trng hp / t hp mun hin: Case/ Combo

- Chn t l khi hin: Scaling

- Chn kiu hin :

+ Wire : Hin s KC (mu ghi nht, m) v dng chuyn v(ng m).

+ Cubic : Ch hin dng chuyn v

4.1.4. Hin cc biu ni lc : Display Show Forces/Stress

Hnh 4.38



260

Sau khi tnh ton, ngi dng c th hin mt s biu ni lc (hnh 4.38) qua cc thao

tc sau:

- Chn trng hp-T hp: Case/Combo

- Chn thnh phn ni lc : Component type

- Chn min : Contour Range

- Chn hin ng sut trung bnh : Stress Averaging

- Hin c s bin dng ca kt cu : Show Deform Shape

Ch :

- Theo phng php phn t hu hn, ng sut v chuyn v s khng lin tc gia cc phn t.

- Ti cng mt nt, gi tr ca cc chuyn v, ni lc ng sut ca cc phn t khc nhau l khng ging nhau .

- Khi thit k nn dng cc gi tr hin th mu trn biu (ch n cc di mu)

4.2. Kt qu ca phn t tm, v xut ra file text.

---------------------------------------------------------

SAP2000 v7.42 File: BT19_KHUNG_DAM_SAN Kgf-m Units PAGE 4

10/16/04 10:50:44

21/6-LND

S H E L L E L E M E N T R E S U L T A N T S

SHELL LOAD JOINT F11 F22 F12 M11 M22 M12 V13 V23 22 LOAD1 2 0.00 0.00 0.00 -373.38 -406.05 -60.29 -422.82 -420.10 64 0.00 0.00 0.00 429.76 99.07 -28.03 -422.82 -150.68 94 0.00 0.00 0.00 137.93 502.88 -12.47 -119.77 -420.10 142 0.00 0.00 0.00 334.97 401.80 19.78 -119.77 -150.68 22 LOAD2 2 0.00 0.00 0.00 -38.30 -58.16 -45.61 -43.76 -48.05



261

64 0.00 0.00 0.00 26.18-5.306E-01 -38.34 -43.76 -60.00 94 0.00 0.00 0.00 -10.36 41.77 -19.69 -58.13 -48.05 142 0.00 0.00 0.00 82.86 126.29 -12.41 -58.13 -60.00 24 LOAD1 64 0.00 0.00 0.00 429.92 99.10 -19.01 450.52 -141.19 20 0.00 0.00 0.00 -443.44 -512.40 -6.33 450.52 -518.67 142 0.00 0.00 0.00 338.57 402.52 -50.15 179.31 -141.19 104 0.00 0.00 0.00 7.62 640.33 -37.47 179.31 -518.67 24 LOAD2 64 0.00 0.00 0.00 26.97-3.721E-01 -12.10 47.98 -61.18 20 0.00 0.00 0.00 -63.63 -154.35 -1.89 47.98 -174.94 142 0.00 0.00 0.00 80.41 125.80 -18.13 23.03 -61.18 104 0.00 0.00 0.00 39.72 227.78 -7.92 23.03 -174.94 SAP2000 v7.42 File: BT19_KHUNG_DAM_SAN Kgf-m Units PAGE 5 10/16/04 10:50:44 21/6-LND S H E L L E L E M E N T P R I N C I P A L S ( Cc lc theo phng chnh) SHELL LOAD JOINT FMAX FMIN MMAX MMIN VMAX 22 LOAD1 2 0.00 0.00 -327.25 -452.18 596.04 64 0.00 0.00 432.12 96.71 448.86 94 0.00 0.00 503.31 137.50 436.84 142 0.00 0.00 407.22 329.55 192.48



262

22 LOAD2 2 0.00 0.00 -1.56 -94.91 64.99 64 0.00 0.00 53.42 -27.77 74.27 94 0.00 0.00 48.37 -16.95 75.42 142 0.00 0.00 129.58 79.57 83.54 24 LOAD1 64 0.00 0.00 431.01 98.01 472.13 20 0.00 0.00 -442.87 -512.98 687.01 142 0.00 0.00 430.02 311.07 228.23 104 0.00 0.00 642.54 5.41 548.79 24 LOAD2 64 0.00 0.00 31.56 -4.96 77.75 20 0.00 0.00 -63.59 -154.39 181.40 142 0.00 0.00 132.15 74.06 65.37 104 0.00 0.00 228.11 39.39 176.45 -------------------------------------------

5. Mt s v d minh ha

Trong phn ny tin cho sinh vin tham kho, chng ti hng dn cch lm theo SAP2000_V7.

5.1. V d Tnh b nc trn :

5.1.1. S liu :

- Dng hnh hc : Cho b hnh tr ng knh 2m, cao 2m

Chia cc y

K5

s4 S4

K4

K3 s S3

s2 S2

K2 S1

K1

Hnh 4.39



263

5.1.2. Cch lm - Gi th vin mu Shell Cylinder ,a vo cc gi tr kch thc : chia tr thnh 18

ng sinh v 4 ng trn ng tm, theo phng Z thnh 10 phn ( nh hnh 4.39).

- Tnh cc din tch S= 0.174 m2 ; S1 = 0.0696 ; S2 =0.0522 ; S3 = 0.0358 ; S4 = 0.0174 m2

- Tnh cc h s n hi : K1= S1*Ks/ 2 ; K2= ((S2+ S1) / 2 )*Ks ;.. . K5 = ( S4*18 )/ 2

- Cc gi tr c th K1=1113.6 T/m ; K2 =1948.8 ; K3= 1408 ; K4=851.2 ; K5 =3340.8 KN/m.

- Khai bo hm Joint Pattern : Theo s liu bi ton tnh c gi tr ca C=-1 ; D= 1.44

2m

1.2 m

1.44

- Khai bo tit din THANH (shell) dy 0.15 v DAY (shell) dy 0.2m.

- Gn cc tit din trn cho thnh v y b.

- Chn cc phn t y gn ti trng Uniform .

- Chn cc phn t thnh gn ti trng Joint Pattern.

- Gn lin kt ni t

+ Trng hp 1 : Chn cc nt ngoi cng gn lin kt khp Assign Joint Restraint

+ Trng hp 2: Chn cc nt gn ti lin kt n hi: Assign Joint Spring Tranlation 3:

Cc nt vng ngoi cng gn gi tr K1; Tng t vi cc vng trong gn ln lt cho

K2,K3,K4 v ti tm c gi tr K5.

- Thc hin tnh ton : Run

Mt s hnh nh kt qu ni lc,ng sut ( hin theo cc di mu hnh 4.40 ) tnh vi

trng hp 1- vi lin kt khp ti y b :



264

Hnh 4.40

5.2. Bi tp ng vm

5.2.1. S liu : dng hnh hc (hnh 4.41)

Hnh 4.26

Hnh 4.41

- Vt liu b tng c E= 2.53 E10 T/ m2; H s Poisson =0.2 ; W = 2.5T/m3

- Kch thc :

+ Chiu cao mi vm 3.05 m ; khong cch gia hai vm 1.525m

+ Chiu rng vm di : 7m ; chiu rng vm trn : 10.5m



265

+ Chiu di ca c vm ng 12.2 m

+ Bn knh vm nh : r1 = 6.1 m ; bn knh vm to r2 = 9.15 m

+ Gc chn hai cung c hai vm 35o

- Chiu dy ca c thnh v sn v t =30.05 cm

- Ti trng : ti trng phn b u ln v ngoi 1462.8 kgf / m2

Yu cu

Tnh ni lc v chuyn v cho hai trng hp ti trng :

+ Trng hp 1 : ch chu ti trng bn thn, h s 1.1

+ Trng hp 2 : Chu ti trng phn b u trn vm to

+ Tnh mt t hp cho c hai trng hp

5.2.2. Hng dn thc hin

5.2.2.1. To lp s kt cu

- To h li theo h trc Decac vi cc tham s : 1 - 1 - 1 - 12.2 - 7 - 3.05 (m)

(ch phng X l phng theo chiu di ca v ). Chn n v Kg-m

- V 2 thnh vm nh trong mt phng XZ: v 2 phn t Shell

+ Dng chc nng Mesh Shell chia nh mi phn t thnh 10 x 4 phn t ( phng X =10 )

+ Gn 2 thnh vm nh cho nhm THANHN .

- V vm nh :

+ Dng chc nng EDIT Add temp Barell vi cc tham s : 8 - 10 - 12.2 - 6.1 - 35 ; Advance Trans Z= 3.05 ( a h trc mi ln theo phng Z =3.05m, b Restaint).

+ Gn cc phn t va to cho nhm MAIN

+ To h to mi tn HE2 vi cc tham s : 1 - 1 - 1 - 12.2 - 10.5 - 3.05 ; Advance Z= 4.575 (m) ( chuyn dch ln theo phng Z so vi h to Global )

+ V 2 thnh vm to trong mt phng XZ : v 2 phn t Shell

+ Dng chc nng Mesh Shell chia nh mi phn t thnh 10 x 4 phn t ( phng X =10 )

+ Gn 2 thnh vm to cho nhm THANHL.



266

- V vm to :

+ Dng chc nng EDIT Add temp Barell vi cc tham s : 8 - 10 - 12.2 - 9.15 - 35 ; Advance Trans Z= 3.05 (a h trc mi ln theo phng Z= 3.05m, b Restaint)

+ Gn cc phn t va to cho nhm MAIL

- V hai thnh v nghing :

+ Chn mt phng nhn : View - Set limit : Z = 3.5 - 4.575 (m)

+ V hai phn t Shell qua 4 im gc ca nh vm nh v y vm ln .

+ Dng chc nng Mesh Shell chia nh thnh 10 x 4 phn t .

+ Gn cc phn t va to cho nhm THANHX

5.2.2.2. Gn cc c trng vt liu cho phn t:

- Khai bo vt liu b tng v mt loi tit din VO c chiu dy 0.3005 m, chn

Type = Shell, thick Plate

- Chn All v gn cho tit din VO

5.2.2.3. Gn lin kt ni t

- Chn cc nt y thnh nh gn lin kt khp c nh.

5.2.2.4. To hai trng hp ti trng - Define Load Case : TH1 c h s Mutiplier = 1.1; TH2 h s Mutiplier =0

- Khai bo t hp : Define Load Combination chn h s cho TH1,TH2 =1

5.2.2.5. Gn ti trng - Chn cc phn t MAIN vo Assign Shell Static Load Uniform:

- Chn Load Case : TH2 ; Direction : Gravity ;

nhp gi tr cho ti trng Uniform= 1462.8

5.3. Tnh b nc ch nht

5.3.1. S liu

- Dng hnh hc : B c kch thc mi chiu 3m, cao 2 m .

- Vt liu : b tng E=2.6E6 T/m2 , h s poisson 0.2 , W= 2.5 T/ m3



267

- Chiu dy : thnh b 0.1 m; y b 0.15m ; c k n trng lng bn thn

- Ti trng : chu p lc thu tnh , h s 1.2

y

x

K1 K1

K1K1 K2 K2 K2 K2 K2

K2

K2

K2

K2

K2

K2 K2 K2 K2 K2

K2

K2

K

K2

K2

2m

3m

3m

Hnh 4.42

Tnh chuyn v v ni lc ca b khi khng cha nc v khi nc cao 1.5m vi 2 s :

b lin kt khp trn bn gc v b t trn nn n hi.

5.3.2. Hng dn

5.3.2.1. To s v gn tI trng

- Chn New modal/ Grid only => xut hin hp thoi New Coord/ Grid system; (n v: T,m)

- Trong hp New Coord/ Grid system nhp cc thng s

+ Number of gridlines X direction: 2; Y direction: 2; Z direction: 2.

+ Grid spacing: X direction: 3; Y direction: 3; Z direction: 2.

- nh ngha tit din thnh b THANH10 v y b DAY15 : Define/ area sections/.

- nh ngha Load case ALTT (define/ static load case/..) vi type l Live; i tn LOAD1 thnh TTBT.

- nh ngha t hp COMB1 gm 1 x TTBT+ 1x ALTT

- mn hnh 2 ca s (options/ windows/ two title vertical), mt bn view dng 3D (bm ) mt bn nhn trong mt phng xz (bm ).

- Chn ca s cha mt phng xz, dng mi tn di chuyn v mt phng Y = 0).

- Dng Quick Draw Area element v thnh b v gn tit din.



268

- Chn thnh b va v, thc hin chia thnh tm nh kch thc 0.5x 0.5m ( Menu Edit / mesh area / into = 6, by = 4);

- nh ngha tn pattern l THUYTINH (define/ joint pattern).

- Chn cc nt c ta t 0 n 1.5.

- Assign/ joint pattern/ .

Nhp cc thng s v cc la chn nh nh

hp thoi pattern data hnh bn. (hnh 1.7)

- Bm OK

- Chn vo ca s 3D.

- Bm biu tng set element chn local axis trong khung area.(hnh 4.43)

Hnh 4.43

s thy trc 3 hng ra pha ngoi b , v vy ta se nhp lc vo mt 5 ca thnh b.

- Chn ht thnh b, tin hnh nhp lc nh v d trc.

- Sau khi nhp lc chn thnh b thc hin Replcate/ Radial to 3 thnh b cn li, cc d liu nh hnh 4.44; kt qu nh hnh 4.45.

Hnh 4.44 Hnh 4.45

- Tng t quay v mt phng XY, thc hin v bn y v gn tit din, chia bn y thnh 6 x 6 phn t. Dng Assign/ area loads/ uniform gn ti trng cho y b (gi

tr= 5, direction = gravity, load case = ALTT)



269

5.3.3. Gn lin kt

- TH1: chn 4 gc/ Menu assign/ Joint / restraint / chn biu tng .

- TH2: b t trn nn n hi vi Ks = 80000 kN/m3.

+ Chn 4 nt 4 gc, Menu Assign/ Joint/ Springs. Trong Spring Stiffness nhp

cng theo phng Translation 3 c gi tr bng K1 loxo. m bo kt cu khng bin

hnh hai phng cn li ta gn cng gi rt

nh. K1loxo c tnh theo cng thc:

K1loxo = Ks x S1

= 80000 x (0.5 x0.5)/4 = 5000 (kN/m)

+ Lm tng t vi cc nt bin: K2loxo = Ks x S2 = 80000 x (0.5 x0.5)/2 = 10000(kN/m)

+ Vi cc nt cn li gia: K3loxo = Ks x S3 = 80000 x (0.5 x0.5)= 20000 kN.

( Xem K1,K2 trong hnh 4.42)

Ch : Khng gn Restraints trng vi Springs.

5.3.3.1. Phn tch.

- Analyze/ Set analysis options/chn c 6 thnh phn chuyn v (hoc space frame) OK

- Analyze/ Run analysis hoc ch ( F5)

S bin dng (SBD) ca b sau khi phn tch

Hnh 4.46 SBD b khp ti 4 gc Hnh 4.47 SBD b trn nn n hi



270

5.4. Tnh thp nc.

5.4.1.1. S liu

Cho chn thp cho nh phn v d 2.12 (chng

3). Trn nh thp c b nc h hnh tr cao 2m cha y nc, bn knh b l 1.5m, chiu dy

thnh b v y b l 10 cm ( hnh 4.48)

Cc ti trng cho nh v d trc.

Yu cu: Tnh ton ni lc v chuyn v ca b.

5.4.1.2. Hng dn

Sau khi to xong chn thp nc.

- nh ngha chiu dy b: Define/ Areas Section. ( be)

- Menu Edit Add to model from templates (Ctrl+T) Chn Shells Cylinder.

- Nhp cc thng s cho nh hnh 4.49, b chn restraint

- Bm Located origin Chn 3D Z = 12

Hnh 4.48

Ch : do dm chia thnh 24 on nn s on chia theo ng knh ca b cng phI l

24 on m bo cc nt trng nhau.

Hnh 4.49

- t cc ti trng nc vo b v tnh ton ( tham kho v d 5.3 tnh b ch nht trn).


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