BAB III PERHITUNGAN STRUKTUR ATAS3.1 Struktur Atap

Gambar 3.1 Rencana Atap Kuda-Kuda Keterangan : K KJ K N G J : Kuda kuda Baja : Kuda kudia Juria : Setengah Kuda kuda : Nok : Gording : Jurai

10

L K J I H G F E D1 37 2 38 20 39 3 40 21 41 22 4 42 43 5 45 44 24 23 6 46 47 48 26 25 7 49 50 8 51 54 52 53 55 56 57 9 10

M11

N12 58

O13 59 60

P14 61 62 63

D"

27

E"

28

F"

Z

C"

29

Q15 64 65 33

G"

30

Y

H"

R16 66 34

31

I"

32

S67 17 68 35

C

191.13

A

V

W

X

J"

K"

T69

L"

18 361.13

B20.40

U

Gambar 3.2 Sketsa Bentuk Kuda-Kuda Keterangan :

Bentang kuda kuda Kemiringan atap ( )

: 20.4 m : 30

Jarak kuda kuda : 3,5 m Jarak gording E baja Mutu baja Penutup atap Beban atap Alat sambung : 1,472 m : 2,1 x 106 kg/cm2 : ST. 37 , = 1600 kg/cm2 : Genteng : 50 kg/m2 : Baut

3.1.1

Panjang Batang

Batang Bawah 20 26 & 29-35

11

Panjang =

1,275 = 1,357 m cos 20

Batang Atas 1 dan 18 Panjang =1,130 = 1,30 m 5 cos 30

Batang Atas 2 17 Panjang =1,275 = 1,472 m cos 30

Batang Horisontal 19 dan 36 Panjang = 1,130 m

Batang Horisontal 27 dan 28 Panjang = 1,275 m

Batang Vertikal Batang 37 dan 69 Panjang =

(1,305 ) 2

(1,130

)2

= 0.653

m

Batang 39 dan 67 Panjang = (2, 405 x tg 30 ) ( 1.275 x tg 20 ) = 0,924 m Batang 41 = 65 Panjang = ( 3,680 x tg 30 ) ( 2,550x tg 20 ) = 1,197 m Batang 43 = 63 Panjang = ( 4,955x tg 30 ) ( 3,825x tg 20 ) = 1,469 m Batang 45 = 61 Panjang = ( 6,230 tg 30 ) ( 5,100x tg 20 ) = 1,741 m Batang 47 = 59

12

Panjang = ( 7,505 x tg 30 ) ( 6,375 x tg 20 ) = 2,013 m Batang 49 = 57 Panjang = ( 8,780 x tg 30 ) ( 7,650 x tg 20 ) = 2,285 m Batang 51 = 55 Panjang = ( 10,055 x tg 30 ) ( 8,925 x tg 20 ) = 2,557 m Batang 53 Panjang = 2,557+( 1,275 x tg 30 ) = 3,293 m Batang Diagonal Batang 38 = 68 Panjang = (1,275 ) 2 Batang 40 = 66 Panjang = (1,275 ) 2 Batang 42 = 64 Panjang = (1,275 ) 2 Batang 44 = 62 Panjang = (1,275 ) 2 Batang 46 = 60 Panjang = (1,275 ) 2 Batang 48 = 58 Panjang = (1,275 ) 2 Batang 50 = 56 Panjang = (1,275 ) 2+ (3,021 ) 2 = 3,279+ (2,749 ) 2 = 3,030 + (2,205 ) 2 = 2,547 + (1,661 ) 2 = 2,094

+ ( 2,405 tg 30 ) 2 =1,885

m

m

+ (1,933 ) 2 = 2,316

m

m

+ ( 2,477 ) 2 = 2,786

m

m

m

13

Batang 52 = 54 Panjang = (1,275 ) 2+ (3,293 ) 2 = 3,531

m

Tabel 3.1 Panjang BatangNO BTG. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 PANJANG BTG. (m) 1,305 1,472 1,472 1,472 1,472 1,472 1,472 1,472 1,472 1,472 1,472 1,472 1,472 1,472 1,472 1,472 1,472 1,305 1,13 1,357 1,357 1,357 1,357 NO BTG. 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 PANJANG BTG. (m) 1,357 1,357 1,357 1,275 1,275 1,357 1,357 1,357 1,357 1,357 1,357 1,357 1,13 0,653 1,885 0,924 2,094 1,197 2,316 1,469 2,547 1,741 2,786 NO BTG. 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 PANJANG BTG. (m) 2,013 3,03 2,285 3,279 2,557 3,531 3,293 3,531 2,557 3,279 2,285 3,03 2,013 2,786 1,741 2,547 1,469 2,316 1,197 2,094 0,924 1,885 0,653 121,877 m

PANJANG BATANG KESELURUHAN

3.1.2

Perencanaan Gording

14

Perhitungan beban dan momen dengan menggunakan trekstang a. Beban Mati Berat atap genteng beton per m2 diambil 50 kg/m2 (PMI 1970). Penutup atap genteng 50 kg/m2 x 1,472 Berat Gording Berat trackstang (10% x berat gording ) q = 73,6 kg/m

= 11,00 kg/m = 1,10 kg/m

= 85,7 kg/m

q qx

qy

qx = 85,7 x cos 30 = 74,218 kg/m qy = 85,7 x sin 30 = 42,285 kg/m My = 1/8 . qx . (L/2)2 = 1/8 . 74,218 . (3,5/2) = 27,646 kg/m Mx = 1/8 . qy . L2 = 1/8 . 42,285 . 3,5 = 64,749 kg/m

b.

Beban Hidup

15

Beban Pekerja dan beban alat (PPIUG 1983), diasumsikan terletak di tengah-tengah bentang sebesar P = 100 kg Py Px P sin = 100 sin 30 = 50 kg P cos = 100 cos 30 = 86,603 kgP x px py y

Mx

= . Py . L = . 86,603 . 3,5 = 75,778 kg

My c. Beban Angin

= . Px . (L/2) = . 50 . 3,5/2 = 21,875 kg

Beban angin 50 kg/m2, dan koefisien muka angin atau tekan (0,02 -0,4), sedangkan koefisien belakang angin atau hisap (-0,4), maka setiap meter gording akan menerima: Angin Tekan

W x

y

Wt = ( 0,02 x 30 0,4 ). 50 . 1,472 = 14,720 kg/m Mx = 1/8 . Wt . (L/2)2 = 1/8 . 14,720 . (3,5/2)2 = 5,635 Kgm 16

My = 0 Angin HisapW x

y

Wh = -0,4 . 50 . 1.472 Mx = 1/8. Wh . (L/2)2 = 1/8. (-29.44). (3,5/2)2 My = 0 d. Beban Air Hujan (G) Beban air hujan, = 30 Beban terbagi rata per m2

= -29,440 kg/m

= -11,27 Kgm

= (40 0,8. ) 20 Kg/m2 = (40 0,8. 30) 20 Kg/m2 = 16 20 Kg/m2.............O. K

G = 16 x jarak gording = 16 x 1,472 = 23,552 Kg/mG x Gx y Gy

Gy Gx

G sin = 23,552 sin 30 = 11,776 kg/m G cos = 23,552 cos 30 = 20,397 kg/m

17

Mx My

= 1/8. Gy . L2 = 1/8. Gx. (L/21)2

= 1/8 . 11,776 . 3,52 = 18,032 Kgm = 1/8 . 20,397 . 3,52 = 7,808 Kgm

3.1.3 Kombinasi Pembebanan Berdasarkan SNI 03-1729-2002 butir 6.2.2Tabel 3.2 Momen dan Beban BEBAN MATI (Kgm) A BEBAN HIDUP (Kgm) B BEBAN HUJAN (Kgm) C BEBAN ANGIN (Kgm) TEKAN (+) HISAP (-) D E

M Mx My

64,749 27,646

75,778 21,875

18,032 7,808

5,635 -

11,27 -

KOMBINASI MOMEN (Kgm) 1,4A 90,6486 38,7044 1,2A + 1,6B 198,9436 68,1752 1,2A + 1,6C 106,55 45,668 1,2A + 1,6B + 0,8D 203,4516 1,2A + 1,6B + 0,8E 207,9596 -

1,2A + 1,6C + 0,8D 111,058 -

1,2A + 1,6C + 0,8E 115,566 -

0,9A + 1,3D 65,5996 -

0,9A + 1,3E 72,9251 -

a. Momen Terhadap Sumbu X Mx max= 207,9596 Kg.m = 20795,96 kg.cm b. Momen Terhadap sumbu Y My max = 68,1752 kg.m = 6817,52 kg.cm

3.1.4

Mendimensi Gording

18

Pilih dimensi gording baja light lip channels 150 x 75 x 20 x 4.520 mm 45 mm 20 mm 75 mm 150 mm

Sx = 65,2 cm3 Sy = 19,8 cm3 Mutu baja : ST 37 Fu (tegangan putus) fy (tegangan leleh) Peregangan minimum

Ix = 489 cm4 Iy = 99,2 cm4

= 3700 kg/cm2 = 2400 kg/cm2 = 20 %

Chek Kekuatan dan Kekakuan Profil Gording a. Kontrol terhadap Lentur (SNI 03-1729-2002 butir 8.1) Mx Mn Mx fy.Sx My Mn My fy.Sy fy.Sx = 0,9 x 2400 x 65,2 = 140.832 kg.cm fy.Sy = 0,9 x 2400 x 19,8 = 42.768 kg.cm adalah faktor reduksi = 0,9 S adalah momen tahanan dari penampang profil baja

Mx max

fy.Sx

19

20795,96 My max 6817,52

140832.(Aman) fy.Sy 42768 .(Aman)

b. Kontrol terhadap Lendutan f f ijin f ijin = L/240 = 175/240 = 0,729 cm (SNI 03-1729-2002 tabel 6.4-1) Tabel 3.3 Kombinasi Pembebanan terhadap Sumbu x

Beban Mati (qx)

Beban air hujan (Gx)

Angin Tekan (Wt)

74,218 74,218 74,218 74,218 74,218

20,397 20,397 20,397-

14,720-

Angin hisap (Wh) -

Jumlah (Qx)

29,440-

14,720-

29,440

109,335 124,055 94,615 88,938 103,658

Qx max = 124,055 kg/m = 1,240 kg/cm

Px =86,602 kg Ix = 489 cm4

Tabel 3.4 Kombinasi Pembebanan terhadap Sumbu y Beban mati (qy) 42,285 42,285 Beban air hujan (Gy) 11,776 Jumlah (Qy) 42,285 54,061

Qy max = 54,061 kg/m = 0,541 kg/cm

Py =50 kg Iy = 99,2 cm4

Lendutan pada sumbu x

20

fx

=

5.Qx .( L / 2) 4 Px .( L / 2) 3 + 384 .Elx 48 .Elx5.1,240 .175 4 86 ,602 .175 3 + 384 .2,1.10 6.489 48 .2,1.10 6 489

=

= 0,015 + 0,009 =0,024 cm Lendutan pada sumbu y fy5.Qy .( L / 2) 4 Py .( L / 2) 3 + = 384 .Ely 48 .Ely

=

5.0,541 .175 4 50 .175 3 + 384 .2,1.10 6.99 ,2 48 .2,1.10 6.99 ,2

= 0,032 +0,026 = 0,059 cm f = f =

( fx ) 2 + ( fy ) 2 f ijin(0,024 ) 2 +(0,059 ) 2

f ijin

= 0,064 cm Jadi dapat digunakan

0,729 cm .(OK) Light Lip Channels 150x75x20x4,5, dengan

gording

penambahan satu trekstang pada tengah-tengah batang.

3.1.5 Perencanaan Kuda-Kuda

21

Analisa Pembebanan Pada Struktur Beban Tetap Beban P1=P19 Beban Kuda-Kuda Beban Atap Beban Gording + Bracing Beban Air Hujan Beban Hidup (Pekerja) = 0,5 x 1,13 x 22 x 3,50 = 0,5 x 1,305 x 50 x 3,50 = (1,20 x 11) x 3,50 = 0,5 x 1,305 x 16 x 3,50 = 43,50 Kg

= 114,19 Kg = 46,20 = 36,54 = 100 Kg Kg Kg +

340,43 Kg

Beban P2=P18 Beban Kuda-Kuda Beban Atap = 0,5 x (1,13+1,275) x 22 x 3,50 = 0,5 x (1,305+1,472) x 50 x 3,50 = (1,20 x 11) x 3,50 = 92,59 Kg

= 242,99 Kg = 46,20 = 77,76 = 100 Kg Kg Kg +

Beban Gording + Bracing Beban Air Hujan Beban Hidup (Pekerja)

= 0,5 x (1,305+1,472) x 16 x 3,50

559,54 Kg

Beban P3 P17 Beban Kuda-Kuda Beban Atap Beban Gording + Bracing = 1,275 x 22 x 3,50 = 1,472 x 50 x 3,50 = (1,20 x 11) x 3,50 = 98,18 Kg

= 257,60 Kg = 46,20 Kg

22

Beban Air Hujan Beban Hidup (Pekerja)

= 1,472 x 16 x 3,50

= 84,43 = 100

Kg Kg +

586,41 Kg Beban Bergerak Beban Angin Muatan angin = 50 kg/m2 (PMI 1970) Kemiringan atap 30 Angin Tekan C = (0,02 . - 0,4) = ( 0,02. 30 0,4 ) = 0,2 Wt1 = 0,2 x muatan angin x luas bidang atap = 0,2 x 50 x (3,5 x 1,472 x 0,5) = 25,76 kg Wt2 = 0,2 x muatan angin x luas bidang atap = 0,2 x 50 x( 3,5 x 1,472) = 51,52 kg

Angin Hisap C = -0,4 = - 0,4 x muatan angin x luas bidang atap / 2 = - 0,4 x 50 x 3,5 x 1,472 x 0,5 = -51,52 kg Wh2 = - 0,4 x muatan angin x luas bidang atap = - 0,4 x 50 x 3,5 x 1,472 = - 103,04 kg

Wh1

23

Angin Tekan W t1y = Wt1 cos 30 = 25,76 cos 30 = 22,31 kg Wt1x= Wt1 sin 30 = 25,76 sin 30 = 12,88 kg

Wt2y = Wt2 cos 30 = 51,52 cos 30 = 44,62 kg

Wt2x = Wt2 sin 30 = 51,52 sin 30 = 25,76 kg

Angin Hisap Wh1y = H1 cos 30 = 51,52 cos 30 = 44,62 kg Wh1x = H1 sin 30 = 51,52 sin 30 = 25,76 kg

Wh2y = H2 cos 30 =103,04 cos 30 = 89,23 kg

Wh2x = H2 sin 30 = 103,04 sin 30 = 51,52 kg

24

3.1.6 Analisa Statika Menghitung reaksi tumpuan 1. Beban TetapP10 P9 P8 P7 P6 P5 P4 P3 P2 P11 19

L9 10

P11 M11 56 57

K8 51

P12 N12 58

J7 49

P13 O13 59 60

I6 46 24 47

54 52 53 55

P14 P14 61 62 63

H5 45 44

50

P15 Q15 64 65 33

G4 42 43

48 26 25

D"

27

E"

28

F"

P16 R16 66 34

F3 40 21 41

E2 38 20 39

Z

C"

29

G"

30

P17 S67 17 68 35

23 22

D37

Y

H"

31

I"

P18 T69

32

C

A RAV1.275

V1.275

W

X

J"

P1918 36

K"

L"

B1.275 1.275 1.275 1.275 1.275 1.275 1.275 1.275 1.275 1.275 1.275 1.275 1.275 1.275

U

RBV1.13

1.13

Gambar 3.3 Sketsa Beban Tetap Kuda-Kuda

MB = 0

(RAV.20,4) (P1.21,53) (P2.20,4) (P3-P17). (19,125+17,85+16,575+15,3+14,025+12,75+11,475+ 10,2+8,925+7,65+6,375+5,1+3,825+2,55+1,275) + (P19.1,13) = 0 (RAV.20,4) (340,43.21,53) (559,54.20,4) (586,41). (19,125+17,85+16,575+15,3+14,025+12,75+11,475+ 10,2+8,925+7,65+6,375+5,1+3,825+2,55+1,275) + (340,43.1,13) = 0 (RAV.20,4) 7329,458 11414,616 89720,73 +384,686 (RAV.20,4) =0

= 108080,118

25

RAV = 5298,045 Kg RAV = RBV = 5298,045 Kg

Kontrol V = 0 RAV + RBV (P1+P2+P3+ + P19) 5298,045 + 5298,045 [(340,43x2)+(559,54x2)+(586,41x15)] = 0 10596,09 Kg = 10596,09 Kg . . . . . . . . OK =0

2. Beban Bergerak Angin KananWh2y Wt2y Wt2y Wt2x 10 9 Wh2y MWt2xWt2y Wh2xK 11 8 Wh2y J N Wt2xWt2y Wh2x 54 51 12 7 Wh2y 52 53 56 O Wt2xWt2y Wh2xI 55 50 13 6 49 Wh2y 57 58 P Wt2xWt2y Wh2x H 48 60 47 14 5 59 Wh2y 27 E" 28 F" 46 QWt2xWt2y Wh2xG 26 D" 29 45 61 62 15 4 Wh2y G" 30 44 25 C" R Wt2xWt2y Wh2xF 43 63 64 24 Z 42 H" 31 16 Wh2y E 3 41 S Wt2xWt2y Wh2x 23 Y 65 I" 32 66 40 17 Wt1y 2 Wh1y 22 X D J" 33 39 67 T Wt2x Wh2x 38 68 21 W K" 34 18 1 69 37 Wt1x Wh1x L" 35 20 V 36 19 A Wh2x Wh2y

L

C

RAV1.275 1.275 1.275 1.275 1.275 1.275 1.275 1.275 1.275 1.275 1.275 1.275 1.275 1.275 1.275

B

U

RBV1.13

1.13

1.275

Gambar 3.4 Sketsa Beban Angin Kanan Kuda-Kuda

26

Tabel 3.5 Beban Angin Kanan TITIK SIMPUL C D E F G H I J K L M N O P Q R S T U MA = 0 BEBAN ANGIN KANAN (Kg) Wh1x = -25,76 Wh2x = -51,52 Wh2x = -51,52 Wh2x = -51,52 Wh2x = -51,52 Wh2x = -51,52 Wh2x = -51,52 Wh2x = -51,52 Wh2x = -51,52 Wh2x + Wt2x = -77,28 Wt2x = -25,76 Wt2x = -25,76 Wt2x = -25,76 Wt2x = -25,76 Wt2x = -25,76 Wt2x = -25,76 Wt2x = -25,76 Wt2x = -25,76 Wt1x = -12,88 Wh1y = 44,62 Wh2y = 89,23 Wh2y = 89,23 Wh2y = 89,23 Wh2y = 89,23 Wh2y = 89,23 Wh2y = 89,23 Wh2y = 89,23 Wh2y = 89,23 Wh2y - Wt2y = 44,61 Wt2y = -44,62 Wt2y = -44,62 Wt2y = -44,62 Wt2y = -44,62 Wt2y = -44,62 Wt2y = -44,62 Wt2y = -44,62 Wt2y = -44,62 Wt1y = -22,31

-(RBV.20,4) + (Wt1y.21,53) + {Wt2y. (20,4+19,125+17,85+16,575+15,3+14,025+12,75+11,475)} {Wt2x.(0,652+1,388+2,124+2,86+3,596+4,332+5,068+5,804)} {(Wh2y-Wt2y) 10,2} {(Wt2x+Wh2x) 6,541} {Wh2y.(8,925+7,65+6,375+5,1+3,825+2,55+1,275)} {Wh2x.(0,652+1,388+2,124+2,86+3,596+4,332+5,068+5,804)} + (Wh1y.1,13) = 0

27

-(RBV.20,4) + (22,31.21,53) + {44,62. (20,4+19,125+17,85+16,575+15,3+14,025+12,75+11,475)} {25,76.(0,652+1,388+2,124+2,86+3,596+4,332+5,068+5,804)} {(44,61) 10,2} {(77,28) 6,541} {89,23.(8,925+7,65+6,375+5,1+3,825+2,55+1,275)} {51,52.(0,652+1,388+2,124+2,86+3,596+4,332+5,068+5,804)} + (44,62.1,13) -(RBV.20,4) + 77,724 RBV = 0 = 0 = 3,81

MB = 0

(RAV.20,4) + (Wh1y.21,53) + {Wh2y. (20,4+19,125+17,85+16,575+15,3+14,025+12,75+11,475)} {Wh2x.(0,652+1,388+2,124+2,86+3,596+4,332+5,068+5,804)} + {(Wh2y-Wt2y) 10,2} {(Wt2x+Wh2x) 6,541} {Wt2y.(8,925+7,65+6,375+5,1+3,825+2,55+1,275)} {Wt2x.(0,652+1,388+2,124+2,86+3,596+4,332+5,068+5,804)} + (Wt1y.1,13) (RAV.20,4) + (44,62.21,53) + {89,23. (20,4+19,125+17,85+16,575+15,3+14,025+12,75+11,475)} {51,52.(0,652+1,388+2,124+2,86+3,596+4,332+5,068+5,804)} + {(44,61) 10,2} {(77,28) 6,541} {44,62.(8,925+7,65+6,375+5,1+3,825+2,55+1,275)} = 0

28

{25,76.(0,652+1,388+2,124+2,86+3,596+4,332+5,068+5,804)} + (22,31.1,13) (RAV.20,4) + 8723,6247 RAV = 0 = 0 = -427,61

V=0

-RAV + RBV + Wh1y + Wh2y.8 + (Wh2y-Wt2y) Wt2y.8 - Wt1y = 0 -427,61 + 3,81 + 44,62 +( 89,23 . 8) + 44,61 (44,62 . 8) - 22,31 423,80 0 =0 = 423,80 =0

H=0 =0 =0 = 734,16

RAH Wh1x 8. Wh2x (Wh2x + Wt2x) 8. Wt2x Wt1x RAH 25,76 8. 51,52 77,28 8. 25,76 12,88 RAH

29

Angin KananWt2y Wh2y

Wh2y Wh2x 10 Wt2y MWh2xWh2y Wt2x K 11 8 Wh2y W t2y N Wh2x Wt2xJ 54 51 12 7 Wh2y Wt2y 52 53 56 O Wh2x Wt2xI 55 50 13 6 49 Wh2y Wt2y 57 58 P Wh2x Wt2x H 48 47 14 5 59 60 Wh2y Wt2y 27 E" 28 F" 46 QWh2x Wt2x G 26 D" 29 45 61 62 15 4 Wh2y Wt2y G" 30 44 25 C" R Wh2x Wt2x F 43 63 64 24 Z 42 H" 31 16 Wh2y W t2y E 3 41 S Wh2x Wt2x 23 Y 65 I" 32 66 40 17 2 Wh1y Wt1y 22 X D J" 33 39 67 T Wh2x Wt2x 38 68 21 W K" 34 18 1 37 69 Wh1x Wt1x L" 35 20 V 36 19 A Wt2x 9

Wt2y

L

C

RAV1.275 1.275 1.275 1.275 1.275 1.275 1.275 1.275 1.275 1.275 1.275 1.275 1.275 1.275 1.275

B

U

RBV1.13

1.13

1.275

Gambar 3.5 Sketsa Beban Angin Kiri Kuda-Kuda Tabel 3.6 Beban Angin KiriTITIK SIMPUL C D E F G H I J K L M N O P Q R S T U BEBAN ANGIN KIRI (Kg) Wt1x = 12,88 Wt1y = -22,31 Wt2x = 25,76 Wt2y = -44,62 Wt2x = 25,76 Wt2y = -44,62 Wt2x = 25,76 Wt2y = -44,62 Wt2x = 25,76 Wt2y = -44,62 Wt2x = 25,76 Wt2y = -44,62 Wt2x = 25,76 Wt2y = -44,62 Wt2x = 25,76 Wt2y = -44,62 Wt2x = 25,76 Wt2y = -44,62 Wt2x + Wh2x = 77,28 Wh2y - Wt2y = 44,61 Wh2x = 51,52 Wh2y = 89,23 Wh2x = 51,52 Wh2y = 89,23 Wh2x = 51,52 Wh2y = 89,23 Wh2x = 51,52 Wh2y = 89,23 Wh2x = 51,52 Wh2y = 89,23 Wh2x = 51,52 Wh2y = 89,23 Wh2x = 51,52 Wh2y = 89,23 Wh2x = 51,52 Wh2y = 89,23 Wh1x = 25,76 Wh1y = 44,62

30

MA = 0

(RBV.20,4) + (Wh1y.21,53) + {Wh2y. (20,4+19,125+17,85+16,575+15,3+14,025+12,75+11,475)} {Wh2x.(0,652+1,388+2,124+2,86+3,596+4,332+5,068+5,804)} + {(Wh2y-Wt2y) 10,2} {(Wt2x+Wh2x) 6,541} {Wt2y.(8,925+7,65+6,375+5,1+3,825+2,55+1,275)} {Wt2x.(0,652+1,388+2,124+2,86+3,596+4,332+5,068+5,804)} + (Wt1y.1,13) (RBV.20,4) + (44,62.21,53) + {89,23. (20,4+19,125+17,85+16,575+15,3+14,025+12,75+11,475)} {51,52.(0,652+1,388+2,124+2,86+3,596+4,332+5,068+5,804)} + {(44,61) 10,2} {(77,28) 6,541} {44,62.(8,925+7,65+6,375+5,1+3,825+2,55+1,275)} {25,76.(0,652+1,388+2,124+2,86+3,596+4,332+5,068+5,804)} + (22,31.1,13) (RBV.20,4) + 8723,6247 RBV = 0 = 0 = -427,61 = 0

MB = 0

-(RAV.20,4) + (Wt1y.21,53) + {Wt2y. (20,4+19,125+17,85+16,575+15,3+14,025+12,75+11,475)} {Wt2x.(0,652+1,388+2,124+2,86+3,596+4,332+5,068+5,804)} {(Wh2y-Wt2y) 10,2} {(Wt2x+Wh2x) 6,541}

31

{Wh2y.(8,925+7,65+6,375+5,1+3,825+2,55+1,275)} {Wh2x.(0,652+1,388+2,124+2,86+3,596+4,332+5,068+5,804)} + (Wh1y.1,13) -(RAV.20,4) + (22,31.21,53) + {44,62. (20,4+19,125+17,85+16,575+15,3+14,025+12,75+11,475)} {25,76.(0,652+1,388+2,124+2,86+3,596+4,332+5,068+5,804)} {(44,61) 10,2} {(77,28) 6,541} {89,23.(8,925+7,65+6,375+5,1+3,825+2,55+1,275)} {51,52.(0,652+1,388+2,124+2,86+3,596+4,332+5,068+5,804)} + (44,62.1,13) -(RAV.20,4) + 77,724 RAV = 0 = 0 = 3,81 = 0

V=0 =0 =0 =-423,80 0 =0

RAV RBV + Wh1y + Wh2y.8 + (Wh2y-Wt2y) Wt2y.8 - Wt1y 3,81 427,61 + 44,62 + (89,23 . 8) + 44,61 (44,62 . 8) - 22,31 -423,80

H=0 =0 =0 =-734,16

RAH + Wh1x + 8. Wh2x + (Wh2x + Wt2x) + 8. Wt2x + Wt1x RAH + 25,76 + 8. 51,52 + 77,28 + 8. 25,76 + 12,88 RAH

32

3.1.7 Perhitungan Dimensi Batang 1. Batang Atas (118)

70.70.7

Panjang Beban Tekan Max ( P max ) Baja ST. 37 tk Digunakan Profil 2 L 70.70 .7 A e = 9,4 cm2 = 1,97 cm

= 147,2 cm = 11528,01 kg = 1600 kg/cm2

Ix = Iy = 42,4 cm4 Kontrol Tekuk Arah Terhadap Sumbu X Ix = 2.Ix = 2 x 42,4 ix =Ix = A84 ,8 2 x9,4

= 84,8 cm 4 = 2,12 cm dimana = 1,144 = 701,492 kg/cm2 ijin=1600kg/cm2

x= =

8 ,8 4 Ix = 2,1 2 ix

= 40

xA

=

1,1 4 x11 2 ,0 4 58 1 2 x9,4

Kontrol Tekuk Arah Terhadap Sumbu Y Iy = 2 . Iy + (2 . A (e + x )2 ) = 2 . 42,4 + (2 . 9,4 (1,97 + 0,5)2)

33

= 199,50 cm4 iy =Iy = A199 ,5 0 2 x9,4

= 3,26 cm dimana = 1,038

y= =

2.Iy 8 ,8 4 = 3,2 iy 6

= 26,00

xA

=

1,038 x11528,01 2 x9,4

= 836,493 kg/cm2 ijin = 1600

kg/cm2 Terhadap Plat Kopel L = =8 ,8 4 2L i min

= 42,4 cm = 2,1 2m 2 x 2 + 2 40 24 ,4 2

= 20 < ijin = 50

( OK )

y=

y 2 +

=

( 26 2 )

(

2

)dimana = 1,212

= 47,70 =

xA

=

1,212 x11528,01 2 x9,4

= 743,189 kg/cm2 ijin =1600kg/cm2 (OK)

Kontrol A ijin = 0,8 xP

= 0,8 x1600

11528,01

= 9,01 cm2

A > A ijin

= 2 . 9,4 cm2 > 9,01 cm2 = 18,8 cm2 > 9,01 cm2 (OK)

34

2.

Batang Bawah (19-36)

60.60.6

10

Panjang Beban Tarik Max ( P max ) Baja ST. 37 tk Digunakan Profil 2 L 60.60.6 A e = 6,91 cm2 = 1,69 cm

= 135,7 cm = 11320,08 kg = 1600 kg/cm2

Ix = Iy = 22,8 cm4 Kontrol Tekuk Arah Terhadap Sumbu X Ix = 2.Ix = 2 x 22,8 ix =Ix = A45,6 2 x 6,91

= 45,6 cm 4 = 1,82 cm dimana = 1,031

x= =

45,6 Ix = 1,82 ix

= 25,05

xA

=

1,031 x11320,08 2 x 6,91

= 844,501 kg/cm2 ijin =1600kg/cm2

Kontrol Tekuk Arah Terhadap Sumbu Y Iy = 2 . Iy + (2 . A ( x + e )2) = 2 . 22,8 + (2 . 6,91 ( 0,5 + 1,69 )2) = 111,88 cm4

35

iy

=

Iy = A

111,88 2 x 6,91

= 2,84 cm dimana = 1,00

y= =

45,6 2.Iy = 2,84 iy

= 16,06

xA

=

1,00 x11320,08 2 x6,91

= 819,11 kg/cm2 ijin =1600 kg/cm2

Terhadap Plat Kopel L = =4 ,6 5 2

= 22,8 cm = 1,8 2m 2 x 2 + 2 25,05 22 ,8 2

L i min

= 12,53 < ijin = 50 ( OK )

y=

y 2 +

=

(16,06 2 )

(

2

)dimana = 1,066 = 873,170 kg/cm2 ijin =1600kg/cm2 (OK)

= 29,76 =

x 1,066 x11320,08 = 2 x6,91A

Kontrol A ijin = 0,8 xP

= 0,8 x1600

113 20,08

= 8,84 cm2

A > A ijin

= 2 . 6,91 cm2 > 8,84 cm2 = 13,82 cm2 > 12,65 cm2 (OK)

3.

Batang Tegak (37,39,41,43,45,47,49,51,53,55,57,59,61,63,65,67,69)

36

45.45.5

10

Panjang Beban Tekan Max ( P max ) Baja ST. 37 tk Digunakan Profil 2 L 45.45.5 A = 4,3 cm2

= 329,30 cm = 3353,24 kg = 1600 kg/cm2

Ix = Iy = 7,83 cm4 e = 1,28 cm

Kontrol Tekuk Arah Terhadap Sumbu X Ix = 2.Ix = 2 x 7,83 ix =Ix = A15 ,66 2 x 4,3

= 15,66 cm 4 = 1,35 cm dimana = 1,00

x= =

1 ,6 5 6 Ix = 1,3 5 ix

= 11,66

xA

=

1,00 x3353,24 2 x 4,3

= 389,91 kg/cm2 ijin =1600kg/cm2

Kontrol Tekuk Arah Terhadap Sumbu Y Iy = 2 . Iy + (2 . A (e + x )2 ) = 2 . 7,83 + (2 . 4,3 (1,28 + 0,5)2) = 42,91 cm4 iy =Iy = A42 ,91 2 x 4,3

= 2,23 cm

37

y= =

2.Iy 15,66 = 2,23 iy

= 7,02

dimana = 1,00

xA

=

1,00 x3353,24 2 x 4,3

= 389,91 kg/cm2 ijin = 1600

kg/cm2 Terhadap Plat Kopel L = =1 ,6 5 6 2

= 7,83 cm = 1,35m 2 x 2 + 2 (11,66 22

L i min

7,8 3

= 5,8 < ijin = 50

( OK )

y=

y 2 +

=

( 7,02 2 )

)dimana = 1,00

= 13,61 =

xA

=

1,00 x3353,24 2 x 4,3

= 389,91 kg/cm2 ijin = 1600

kg/cm2 Kontrol A ijin = 0,8 xP

= 0,8 x1600

3353,24

= 2,62 cm2

A > A ijin

= 2 . 4,3 cm2 > 2,62 cm2 = 8,6 cm2 > 2,62 cm2 (OK)

4.

Batang Diagonal (38,40,42,44,46,48,50,52,54,56,58,60,62,64,66,68) 38

45.45.5

10

Panjang Beban Tarik Max ( P max ) Baja ST. 37 tk Digunakan Profil 2 L 45.45.5 A = 4,3 cm2

= 353,31 cm = 3519,95 kg = 1600 kg/cm2

Ix = Iy = 7,83 cm4 e = 1,28 cm

Kontrol Tekuk Arah Terhadap Sumbu X Ix = 2.Ix = 2 x 7,83 ix =Ix = A15 ,66 2 x 4,3

= 15,66 cm 4 = 1,35 cm dimana = 1,00 kg/cm2 ijin

x= =

1 ,6 5 6 Ix = 1,3 5 ix

= 11,66 = 409,296

xA

=

1,0 x351 ,95 0 9 2 x 4,3

=1600kg/cm2 Kontrol Tekuk Arah Terhadap Sumbu Y Iy = 2 . Iy + (2 . A (e + x )2 ) = 2 . 7,83 + (2 . 4,3 (1,28 + 0,5)2) = 42,91 cm4

39

iy

=

Iy = A

42 ,91 2 x 4,3

= 2,23 cm dimana = 1,00

y= =

15,66 2.Iy = 2,23 iy

= 7,02

xA

=

1,0 x351 ,95 0 9 2 x 4,3

= 409,296 kg/cm2 ijin = 1600

kg/cm2 Terhadap Plat Kopel L = =1 ,6 5 6 2L i min

= 7,83 cm = 1,35m 2 x 2 + 2 11,66 27,8 3

= 5,8 < ijin = 50

( OK )

y=

y 2 +

=

( 7,02 2 )

(

2

)dimana = 1,00

= 13,61 =

xA

=

1,0 x351 ,95 0 9 2 x 4,3

= 409,296 kg/cm2 ijin = 1600

kg/cm2 Kontrol A ijin = 0,8 xP

= 0,8 x1600

3519,95

= 2,75 cm2

A > A ijin

= 2 . 4,3 cm2 > 2,75 cm2 = 8,6 cm2 > 2,75 cm2 (OK)

40

3.1.8 Analisa Sambungan A. Data Perencanaan - Profil yang digunakan 2 L 70.70.7, 2 L 60.60.6 dan 2 L 45.45.5 - Alat sambung dengan baut 19 mm, 16 mm dan 13 mm - Tebal plat simpul - Mutu baja ST . 37 = 10 mm

ijin ijin

= 1600 kg/cm2 = 2400 kg/cm2

- Kekuatan baut ST . 52

B. Kekuatan satu buah baut 19 mm Terhadap Geser F = m . n . . d2 = 2 . 1 . . . 1,92 . 0,6 . 2400 = 13602,48 kg Terhadap Tumpu F = n . d . t . . tu = 1 . 1,9 . 1,0 . 1,2 . 1600 = 3648 kg Diambil F yang terendah, yaitu 3648 kg

C. Kekuatan 1 Buah Baut 16 mm Terhadap Geser F = m . n . . d 2 = 2 . 1 . . . 1,62 . 0,6 . 2400 41

= 5790,584 kg Terhadap Tumpu F = n . d . t . . tu = 1 .1,6 . 1,0 . 1,2 .1600 = 3072 kg Diambil F yang terendah, yaitu 3072 kg

D. Kekuatan 1 Buah Baut 13 mm Terhadap Geser F = m . n . . d 2 = 2 . 1 . . . 1,32 . 0,6 . 2400 = 3820,75 kg Terhadap Tumpu F = n . d . t . . tu = 1 .1,3 . 1,0 . 1,2 .1600 = 2496 kg Diambil F yang terendah, yaitu 2496 kg

Rumus jumlah baut (n) = N s g Jarak antar baut (s) = 2,5d 7d Jarak antar tepi plat (s1) = 1,5d 3d

P

42

Tabel 3.7 Jumlah BautNO BT G 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 GAYA BTG (KG) 90,72 1585,42 6483,4 9528,34 10992,08 11505,11 11425,55 11528,01 6627,57 6747,19 11034,08 10731,79 10636,26 10223,3 8909,1 6087,33 1460,96 127,3 179,16 5164,31 8893,97 10646,61 11320,08 11351,7 11120,58 2L 70.70.7 2L 70.70.7 2L 70.70.7 2L 70.70.7 2L 70.70.7 2L 70.70.7 2L 70.70.7 2L 70.70.7 2L 70.70.7 2L 70.70.7 2L 70.70.7 2L 70.70.7 2L 70.70.7 2L 70.70.7 2L 70.70.7 2L 70.70.7 2L 70.70.7 2L 70.70.7 2L 60.60.6 2L 60.60.6 2L 60.60.6 2L 60.60.6 2L 60.60.6 2L 60.60.6 2L 60.60.6 BAUT (mm) 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 16 16 16 16 16 16 16 JUMLAH BAUT (n) 0,024868 4 0,434599 8 1,777247 8 2,611935 3 3,013179 8 3,153813 3,132003 8 3,160090 5 1,816768 1 1,849558 7 3,024693 2,941828 4 2,915641 4 2,802439 7 2,442187 5 1,668676 0,400482 5 0,034895 8 0,058320 3 1,681090 5 2,895172 5 3,465693 4 3,684921 9 3,695214 8 3,619980 5 2 2 2 3 4 4 4 4 2 2 4 4 4 3 3 2 2 2 2 2 3 4 4 4 4 JARAK S1 (mm) 35 35 35 35 35 35 35 35 35 35 35 35 35 35 35 35 35 35 30 30 30 30 30 30 30 JARAK S (mm) 50 50 50 50 50 50 50 50 50 50 50 50 50 50 50 50 50 50 50 50 50 50 50 50 50

PROFIL

43

26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55

9495,26 8613,66 8598,08 9253,03 10404,08 10365,91 10110,49 9299,21 7622,01 4157,92 184,5 1951,16 5217,15 3353,24 3745,72 955,53 2095,2 464,42 1016,85 55,79 323,58 501,94 402,8 1608,36 2775,61 3170,61 810,02 736,07 864,63 3599,6

2L 60.60.6 2L 60.60.6 2L 60.60.6 2L 60.60.6 2L 60.60.6 2L 60.60.6 2L 60.60.6 2L 60.60.6 2L 60.60.6 2L 60.60.6 2L 60.60.6 2L 45.45.5 2L 45.45.5 2L 45.45.5 2L 45.45.5 2L 45.45.5 2L 45.45.5 2L 45.45.5 2L 45.45.5 2L 45.45.5 2L 45.45.5 2L 45.45.5 2L 45.45.5 2L 45.45.5 2L 45.45.5 2L 45.45.5 2L 45.45.5 2L 45.45.5 2L 45.45.5 2L

16 16 16 16 16 16 16 16 16 16 16 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13

3,090904 9 2,803925 8 2,798854 2 3,012054 3,386744 8 3,374319 7 3,291175 1 3,027086 6 2,481123 1,353489 6 0,060058 6 0,781714 7 2,090204 3 1,343445 5 1,500689 1 0,382824 5 0,839423 1 0,186065 7 0,407391 8 0,022351 8 0,129639 4 0,201097 8 0,161378 2 0,644375 1,112023 2 1,270276 4 0,324527 2 0,294899 8 0,346406 3 1,442147

4 3 3 4 4 4 4 4 3 2 2 2 3 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

30 30 30 30 30 30 30 30 30 30 30 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20

50 50 50 50 50 50 50 50 50 50 50 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40

44

56 57 58 59 60 61 62 63 64 65 66 67 68 69

2676,91 1587,06 513,81 557,96 431,76 229,85 1151,66 610,05 2126,15 1015,75 3519,95 3258,02 4982,28 1870,61

45.45.5 2L 45.45.5 2L 45.45.5 2L 45.45.5 2L 45.45.5 2L 45.45.5 2L 45.45.5 2L 45.45.5 2L 45.45.5 2L 45.45.5 2L 45.45.5 2L 45.45.5 2L 45.45.5 2L 45.45.5 2L 45.45.5

4 13 13 13 13 13 13 13 13 13 13 13 13 13 13 1,07248 0,635841 3 0,205853 4 0,223541 7 0,172980 8 0,092087 3 0,461402 2 0,244411 1 0,851822 9 0,406951 1 1,410236 4 1,305296 5 1,996105 8 0,749443 1 2 2 2 2 2 2 2 2 2 2 2 2 2 2 20 20 20 20 20 20 20 20 20 20 20 20 20 20 40 40 40 40 40 40 40 40 40 40 40 40 40 40

45