Tugas Besar Baja ARJ
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Transcript of Tugas Besar Baja ARJ
Tugas Besar Struktur Baja
Hadi Jatmoko 201210340311160
Arif Rachman Julianto 201210340311186
ANALISA DAN PERHITUNGAN
Direncanakan Bangunan Gedung Industri berbahan baja serta gambar kerjanya dengan data-
data sebagai berikut :
1. Bentang Kuda-kuda (L) : 12,5 m
2. Profil Kuda-kuda : WF (wide flange)
3. Jumlah Kuda-kuda (n) : 6
4. Jarak antar Kuda-kuda : 7 m
5. H1 : 5,5 m
6. Sudut α : 20º
7. Beban Angin : 35 kg/cm2
8. Jenis Atap : Zincalum
9. Dinding Samping : Tertutup (Zincalum)
10. Ikatan Angin Dinding : Portal baja
11. Mutu Baja : A36
12. Jenis Sambungan : Baut (A325)
13. Struktur Balok Crane dengan beban bergerak : 15 ton
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Tinggi Kuda-kuda
tan 20º = tinggi6,25
tinggi = tan 20º x 6,25 = 2,27 m
Dengan Kemiringan
√6,252+2,272 = 6,65 m
Jarak Antar Gording
6,655
= 1,33 m ≈ 1,40 m
Perhitungan Beban Pada Atap
1. Beban Mati
Jarak antar gording = 1,40 m
Berat penutup atap (Zincalum) = 4,10 kg/m
Berat gording diperkirakan = 6 kg/m
Berat atap (1,40 x 4,10) = 5,74 kg/m
Berat gording = 6 kg/m +
qD = 11,74 kg/m
qD = 11,74 kg/m => RD =
12
. qD . L =
12
.(11 , 74 ).(7 ) = 41,09 kg
RDx = (41,09).cos 20° = 38,61 kg
RDy = (41,09).sin 20° = 14,05 kg
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qD = 11,74 kg/m =>MD =
18
. qD . L2
=
18
.(11 , 74 ). (7 )2
= 71,91 kgm
MDx = (71,91).cos 20° = 67,57 kgm
MDy = (71,91).sin 20° = 24,59 kgm
2. Beban Hidup
Berat pekerja = 100 kg
PL = 100 kg => RL =
12
.PL=
12
.(100) = 50 kg
RLx = (50).cos 20° = 46,98 kg
RLy = (50).sin 20° = 17,10 kg
PL = 100 kg => ML =
14
. PL . L=
14
.(100) .(7 )= 175 kgm
MLx = (175).cos 20° = 164,45 kgm
MLy = (175).sin 20° = 59,85 kgm
3. Beban Angin
Angin tekan, q = {(0,02).α – (0,4)}. (Wangin) . (Jarak antar gording)
= {(0,02).(20) – (0,4)}.(35).(1,4)
= 0 kg/m
q = 0 kg/m => Rw =
12
.q .L=
12
.(0 ).(7 )= 0 kg
Mw =
18
. q . L2
=
18
.(0 ).(7 )2
= 0 kgm
Angin hisap, q = (- 0,4). (Wangin) . (Jarak antar gording)
= (- 0,4).(35).(1,4)
= - 19,6 kg/m
q = - 19,6 kg/m => Rw =
12
.q .L=
12
.(−19 ,6 ) .(7)= - 68,6 kg
Mw =
18
. q . L2
=
18
.(−19 , 6) .(7 )2
= - 120,05 kgm
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Kombinasi Pembebanan
A. Pembebanan Sementara 1
1. Arah Tegak Lurus Bidang Atap
RUx1 = (1,2).(RDx) + (0,5).(RLx) + (1,3).(Rw)
= (1,2).( 38,61) + (0,5).( 46,98) + (1,3).(0)
= 69,822 kg
RUx2 = (1,2).(RDx) + (0,5).(RLx) + (1,3).(Rw)
= (1,2).( 38,61) + (0,5).(46,98) + (1,3).( - 68,6)
= -19,358 kg
2. Arah Sejajar Bidang Atap
RUy = (1,2).(RDy) + (0,5).(RLy)
= (1,2).( 14,05) + (0,5).( 17,10)
= 25,410 kg
B. Pembebanan Tetap
1. Arah Tegak Lurus Bidang Atap
RUx = (1,2).(RDx) + (0,5).(RLx)
= (1,2).( 38,61) + (0,5).(46,98)
= 69,822 kg
2. Arah Sejajar Bidang Atap
RUy = (1,2).(RDy) + (0,5).(RLy)
= (1,2).(14,05) + (0,5).(17,10)
= 25,410 kg
C. Pembebanan Sementara 2
1. Arah Tegak Lurus Bidang Atap
RUx 1 = (1,2).(RDx) + (1,6).(RLx) + (0,8).(Rw)
= (1,2).( 38,61) + (1,6).(46,98) + (0,8).(0)
= 121,500 kg
RUx 2 = (1,2).(RDx) + (1,6).(RLx) + (0,8).(Rw)
= (1,2).( 38,61) + (1,6).(46,98) + (0,8).( - 68,6)
= 66,620 kg
2. Arah Sejajar Bidang Atap
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RUy = (1,2).(RDy) + (1,6).(RLy)
= (1,2).(14,05) + (1,6).(17,10)
= 44,220 kg
D. Pembebanan Sementara 3
1. Arah Tegak Lurus Bidang Atap
RUx = (0,9).(RDx) + (1,3).(Rw)
= (0,9).( 38,61) + (1,3).(0)
= 34,749 kg
RUx = (0,9).(RDx) + (1,3).(Rw)
= (0,9).( 38,61) + (1,3).( - 68,6)
= - 54,431 kg
2. Arah Sejajar Bidang Atap
RUy = (0,9).(RDy)
= (0,9).(14,05)
= 12,645 kg
Kombinasi Momen
A. Momen Akibat Beban Sementara 1
1. Arah Tegak Lurus Bidang Atap
MUx1 = (1,2).(MDx) + (0,5).(MLx) + (1,3).(Mw)
= (1,2).( 67,57) + (0,5).( 164,45) + (1,3).(0)
= 163,309 kgm
MUx2 = (1,2).(MDx) + (0,5).(MLx) + (1,3).(Mw)
= (1,2).( 67,57) + (0,5).( 164,45) + (1,3).(- 120,05)
= 7,244 kgm
2. Arah Sejajar Bidang Atap
MUy = (1,2).(MDy) + (0,5).(MLy)
= (1,2).( 24,59) + (0,5).( 59,85)
= 59,433 kgm
B. Momen Akibat Beban Tetap
1. Arah Tegak Lurus Bidang Atap
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MUx = (1,2).(MDx) + (0,5).(MLx)
= (1,2).( 67,57) + (0,5).( 164,45)
= 163,309 kgm
2. Arah Sejajar Bidang Atap
MUy = (1,2).(MDy) + (0,5).(MLy)
= (1,2).( 24,59) + (0,5).( 59,85)
= 59,433 kgm
C. Momen Akibat Beban Sementara 2
1. Arah Tegak Lurus Bidang Atap
MUx1 = (1,2).(MDx) + (1,6).(MLx) + (0,8).(Mw)
= (1,2).( 67,57) + (1,6).( 164,45) + (0,8).(0)
= 344,204 kgm
MUx2 = (1,2).(MDx) + (1,6).(MLx) + (0,8).(Mw)
= (1,2).( 67,57) + (1,6).( 164,45) + (0,8).(- 120,05)
= 248,164 kgm
2. Arah Sejajar Bidang Atap
MUy = (1,2).(MDy) + (1,6).(MLy)
= (1,2).( 24,59) + (1,6).( 59,85)
= 125,268 kgm
D. Momen Akibat Beban Sementara 3
1. Arah Tegak Lurus Bidang Atap
MUx1 = (0,9).(MDx) + (1,3).(Mw)
= (0,9).( 67,57) + (1,3).( 0)
= 60,813 kgm
MUx2 = (0,9).(MDx) + (1,3).(Mw)
= (0,9).( 67,57) + (1,3).( -120,05)
= - 95,252 kgm
2. Arah Sejajar Bidang Atap
MUy = (0,9).(MDy)
= (0,9).( 24,59)
= 22,131kgm
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Tugas Besar Struktur Baja
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Tabel Hasil Perhitungan Kombinasi Momen dan Reaksi
Keterangan Beban TetapBeban Sementara 1 Beban Sementara 2 Beban Sementara 3
Angin Tekan Angin Hisap Angin Tekan Angin Hisap Angin Tekan Angin HisapMomen
Mx 163,309 kgm 163,309 kgm 7,244 kgm 344,204 kgm 248,164 kgm 60,813 kgm (-) 95,252 kgmMy 59,433 kgm 59,433 kgm 125,268 kgm 22,131 kgm
Reaksi Rx 69,822 kg 69,822 kg (-) 19,358 kg 121,50 kg 66,620 kg 34,749 kgm (-) 54,431 kgRy 25,410 kg 25,410 kg 44,220 kg 12,645 kg
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Perencanaan Gording Atap
Diambil profil C-Channel 150x65x20 dengan tebal 2,50 mm
q = 5,96 kg/m
t = 2,50 mm Cy = 2,12 cm
A = 7,59 cm2 Xo = 5,15 cm
Ix = 267 cm4 J = 1581 cm4
Iy = 44 cm4 Cw = 2148 cm6
Zx = 35,6 cm3
Zy = 10,0 cm3
rx = 5,93 cm
ry = 2,41 cm
Mutu Baja = A36 = 36 x 1ksi = 36 x 6,875 = 247,5 MPa = 2475 kg/cm2
Momen Nominal Penampang C-Channel
𝑍𝑥 = 14
ℎ𝑡 𝑡2 + 𝑎 𝑡 (ℎ𝑡 – 𝑎) + 𝑡(𝑏 − 2𝑡) (ℎ𝑡 − 𝑡)
= 14
. 150 . 2,52 + 20 x 2,5 (150 - 20) + 2,5 (65 – 2 . 2,5) (150 – 2,5)
= 28,9 cm3
𝑍𝑦 = ℎ𝑡 𝑡 (𝑐 – 12
𝑡) + 2𝑎𝑡 (𝑏 − 𝑐 – 12
𝑡) + 𝑡(𝑐 − 𝑡)2 + 𝑡(𝑏 − 𝑡 − 𝑐)2
= 150 . 2,5 (21,2 - 12
2,5) + 2 . 20 . 2,5 (65 – 21,2 - 12
2,5) + 2,5(21,2 – 2,5)2 + 2,5(65
–
2,5 – 21,2) 2
= 16,9 cm3
Mnx = Zx fy = 28,9 x 2475 kg/cm2 = 71527,5 kgcm
Mny = Zyfy = 16,9 x 2475 kg/cm2 = 41827,5 kgcm
Persyaratan Momen Biaxial
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MuxØ x Mnx
+ MuyØ x Mny < 1,0
344 , 204 x 1000,9 x71527,5
+125 , 268 x1000,9x 41827 , 5 = 0,87 < 1,0
Lendutan Pada Profil C - Channel
∆max =
L240
=
700240
= 2,92 cm
qD = 11,74 kg/m => qDx = (11,74).cos 20° = 11,032 kg/m
qDy = (11,74).sin 20° = 4,015 kg/m
PD = 100 kg => PDx = (100).cos 20° = 93,97 kg
PDy = (100).sin 20° = 34,20 kg
Lendutan terhadap sumbu x :
qx = (1,2).qDx = (1,2).(11,032) = 13,2384 kg/m
Px = (1,2).PDx = (1,2).(93,97) = 112,764 kg
∆x =
5384
.qx .L4
E . I x +
148
.Px . L3
E . I x
=
5384
.(0 , 132384 ).(7004 )(2000000 ).(267 )
+ 148
.(112 ,764 ) .(7003 )(2000000) .(267 )
= 0,775 + 1,509
= 2,284 cm = 22,84 mm
Lendutan terhadap sumbu y :
qy = (1,2).qDy = (1,2).(4,015) = 4,818 kg/m
Py = (1,2).PDy = (1,2).(34,20) = 41,04 kg
∆y =
5384
.q y . L4
E . I y +
148
.Py . L3
E . I y
=
5384
.(0 , 04818 ).(3504 )(2000000) .(44 )
+ 148
.(41 , 04 ).(3503 )(2000000 ) .(44 )
= 0,107 + 0,417
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= 0,524 cm = 5,24 mm
∆ = √( Δ x)2+( Δ y )
2
= √(2 , 284 )2+(0 ,524 )2
= 2,343 cm < ∆max = 2,92 cm
Jadi gording dengan profil C 150x65x20, dengan tebal 2,5 mm dapat digunakan karena
telah memenuhi persyaratan.
7 msagrod
gording
1.4 m
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Perencanaan Sagrod
Cek kelangsingan sagrod
λ =
lkimin
< 300
i =
lk300 =
140300 = 0,47
i =
14 ×d
d = 4 × i
= 4 × 0,47
= 1,88 ≈ 1,9 cm = 19 mm
A =
14 × π × d2 I =
164 × π× d4 i min= √ I
A
=
14 ×π ×1,92 =
164 × π ×1,94 i min= √ 0 ,64
2,84
= 2,84 cm2 = 0,64 cm4 i min= 0,48 cm
λ =
lkimin
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=
1400 ,48 = 291,67 < 300
Gaya yang bekerja pada sagrod :
Pu = 2 × Ruy
= 2 × 44,220
= 88,440 kg
f =
Pu
Ag
=
88 , 440
0,9×14×π×1,92
= 34,68 kg/cm2 < 2475 kg/cm2
88,440
kg
Ø 19 mm
88,440 kg
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Perhitungan Beban Pada Dinding
1. Beban Mati
Jarak antar gording = 2,75 m → 5,5 m : 2 = 2,75 m
Berat penutup atap (Zincalum) = 4,10 kg/m
Berat gording diperkirakan = 6 kg/m
Berat dinding = 4,10 kg/m
Berat gording = 6 kg/m +
qD = 10,10 kg/m
qD = 10,10 kg/m => RDx = 0
RDy =
12
. qD . L =
12
.(10 ,10 ) .(5,5) = 27,78 kg
qD = 10,10 kg/m => MDx = 0
MDy =
18
. qD .L2
=
18
.(10 ,10) .(5,5 )2= 38,19 kgm
2. Beban Angin
Angin tekan, q = (0,9).p
= 0,9 x 35
= 31,50 kg/m
q = 31,50 kg/m => My = 0 kgm
Mx =
18
. qD . L2
=
18
.(31 ,50x 2 ,75 ). (5,52)= 327,55 kgm
Angin hisap, q = (-0,4).p
= (-0,4) x 35
= - 14 kg/m
q = - 14 kg/m => My = 0 kgm
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Mx =
18
. qD . L2
=
18
.(−14 x2 , 75 ).(5,52 )= - 145,58 kgm
A. Momen Akibat Beban Tetap
1. Arah Tegak Lurus Bidang Dinding
MUy = (0,8).(My) MUx = (1,2).(MDx)
= (0,8).( 38,19) = (1,2).( 327,55)
= 30,55 kgm = 393,06 kgm
Perencanaan Gording Dinding
Diambil profil C-Channel 150x65x20 dengan tebal 2,50 mm
q = 5,96 kg/m
t = 2,50 mm Cy = 2,12 cm
A = 7,59 cm2 Xo = 5,15 cm
Ix = 267 cm4 J = 1581 cm4
Iy = 44 cm4 Cw = 2148 cm6
Zx = 35,6 cm3
Zy = 10,0 cm3
rx = 5,93 cm
ry = 2,41 cm
Mutu Baja = A36 = 36 x 1ksi = 36 x 6,875 = 247,5 MPa = 2475 kg/cm2
Momen Nominal Penampang C-Channel
𝑍𝑥 = 14
ℎ𝑡 𝑡2 + 𝑎 𝑡 (ℎ𝑡 – 𝑎) + 𝑡(𝑏 − 2𝑡) (ℎ𝑡 − 𝑡)
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= 14
. 150 . 2,52 + 20 x 2,5 (150 - 20) + 2,5 (65 – 2 . 2,5) (150 – 2,5)
= 28,9 cm3
𝑍𝑦 = ℎ𝑡 𝑡 (𝑐 – 12
𝑡) + 2𝑎𝑡 (𝑏 − 𝑐 – 12
𝑡) + 𝑡(𝑐 − 𝑡)2 + 𝑡(𝑏 − 𝑡 − 𝑐)2
= 150 . 2,5 (21,2 - 12
2,5) + 2 . 20 . 2,5 (65 – 21,2 - 12
2,5) + 2,5(21,2 – 2,5)2 + 2,5(65
–
2,5 – 21,2) 2
= 16,9 cm3
Mnx = Zx fy = 28,9 x 2475 kg/cm2 = 71527,5 kgcm
Mny = Zyfy = 16,9 x 2475 kg/cm2 = 41827,5 kgcm
Persyaratan Momen Biaxial
MuxØ x Mnx
+ MuyØ x Mny < 1,0
393 , 06 x1000,9 x71527,5
+30 ,55 x 1000,9 x 41827 , 5 = 0,69 < 1,0
Cek Kelangsingan Gording
λ =
lkimin
< 300
=
5502 ,41 < 300
= 228,22 < 300
Jadi gording dengan profil C 150x65x20, dengan tebal 2,5 mm dapat digunakan karena
telah memenuhi persyaratan.
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Perhitungan Ikatan Angin (Bracing)
1. Pada Atap
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Beban angin samping (bagian atap)
Luas bidang A = 1/2 x 12,5 x 2,27
= 14,188 m2
Tekanan angin P = 35 kg/m2
W = 0,9 x 14,188 x 35
= 446,922 kg
Tiap titik simpul, Wa= 1/8 x 446,922
= 55,865 kg
Beban angin samping (bagian atap)
55,865 kg
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55,865 kg
55,865 kg
55,865 kg
11 kg11 kg
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Tan α = 1,33
7
α = 18º
R x 7 = 55,865 x 1,33
R = 10,61 kg = 11 kg
ƩH = 0
55,865 – S cos 18o = 0
55,865 – S (0,951057) = 0
-S (0,951057) = - 55,865
S = 58,740 kg
Digunakan Profil L Siku Sama Sisi 120 x 120 x 8
55,865 kg
11 kgS
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q = 14,70 kg/m
A = 18,76 cm2
Cx = Cy = 3,20 cm
Ix = Iy = 258 cm4
I min = 106 cm4
I max = 410 cm4
Zx = Zy = 29,50 cm3
ix = iy = 3,710 cm
i min = 2,38 cm
i max = 4,67 cm
Cek Kelangsingan Bracing
Panjang bracing atap , lk = √72+1,332 = 7,125 m
λ = lkimin
< 300
712,52,38
< 300
299,4 < 300
Cek Kekuatan Penampang
Nu = (1,3) x (58,740)
= 76,362 kg
Nu = 76,362 kg ≤ ØNn = 0,9 x 18,76 x 2475
Nu = 76,362 kg ≤ ØNn = 41787,9 kg
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2. Pada dinding
Beban angin samping (bagian dinding)
Dipakai portal baja
Luas bidang A = 12,5 x 5,5
= 68,75 m2
Tekanan angin P = 35 kg/m2
W = 0,9 x 68,75 x 35
= 2165,63 kg
Tiap titik simpul Wa= 1/4 x 2165,63
= 541,41 kg
ΣMA = 0
(541,41).(5,5) = RB.(7)
RB = 425,39 kg
RA = -425,39 kg
Tan θ =
5,57
ΣV = 0
S.sin (38) = 425,39 kg
S = 690,95 kg
PU = (1,3).( 690,95)
= 898,235 kg
θ = 38o
541,41 kg
541,41 kg
RA RB
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Dicoba profil WF (125x125x6,5x9)
H = 125 mm
B = 125 mm
t1 = 6,5 mm
t2 = 9 mm
r = 10 mm
A = 30,31 cm2
ix = 5,29 cm
iy = 3,11 cm
Cek kelangsingan
Panjang batang, L = √5,52+72 = 8,90 m
λ =
Limin < 300
=
8903 ,11 < 300
= 286,17 < 300
Cek kekuatan penampang
Nu = (1,3) x (690,95)
= 898,235 kg
Nu = 898,235 kg ≤ ØNn = 0,9 x Ag x 2475
Nu = 898,235 kg ≤ ØNn = 0,9 x 30,31 x 2475
Nu = 898,235 kg ≤ ØNn = 67515,525 kg
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Spesifikasi KCI – Hoist Crane
Model : 15D.T11
Hoist type : 15D
Trolley type : 15DT
Capacity : 15 ton
Dimension :
L : 8000 mm
H : 785 mm
K : 730 mm
R : 1000 mm
F : 700 mm
E : 740 mm
Weight: 2150 kg
Pcrane : 2150 kg
Pcropcrane : 15000 kg
Pfootwalk : 100 kg +
17250 kg
Perhitungan Pembebanan
λ = 1,04 m’ (Lihat Tabel Hoist Crane)
λ < 0,586 L
λ < 0,586 . 11
λ < 6,446 m’
Mmax = P/2L (L – a/2)2
λ = 104 cm = 1,04
m
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M max=(17,25 ) x1 /2
2(11)×(11−1,04
2)
2
= 43,06 tm’ x 1,15 (ambil impact factor = 15 %)
= 49,52 tm’
V = P ׿)
= 8,625 ×(2−1,0411
)
= 16,43 ton
Pra-Desain penampang
Lh
< 2511h
< 25 ; h = 45 cm
Lb
< 6511b
< 65 ; b = 18 cm
Di ambil ;
h = 90 cm Lh
= 110,9
= 12,22 < 25 OK
b = 80 cm Lb
= 110,8
= 13,75 < 65 OK
Perencanaan Penampang Balok
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Cek Stabilitas
Tekuk lokal pada sayap (flens)
λ = Btf
= 36,51,5
= 24,33
λp = 1,40 √ Efy
= 1,40 √ 200000247,5
= 39,80( λ ≤ λp )
Tekuk lokal pada badan (web)
λ = Ht
= 862,5
= 34,40
λp = 1,49 √ Efy
= 1,49 √ 200000247,5
= 42,36 ( λ ≤ λp )
(Penampang Balok Girder Crane Melintang Kompak) → OK
* Luas Profil FI = 60 x 1,5 = 90 cm2
FII = 2,5 x 86 = 215 cm2
FIII = 2,5 x 86 = 215 cm2
FIV = 80 x 2,5 = 200 cm2
* Luas Penampang
A = A1 + A2 + A3 + A4
= 90 + 215 + 215 + 200
= 720 cm2
* Garis Berat Penampang
Y = F 1∙ y 1+F 2∙ y 2+F 3 ∙ y3+F 4 ∙ y 4
∑ F
= (90×0,75 )+ (215× 44,50 )+(215× 44,50 )+(200×88,75)
720
= 51,32 cm
X = 40 cm
* Momen Inersia
Ix = Ix1 + Ix2 + Ix3 + Ix4
Ix1 = 1
12∙ b∙ h3+F ∙a2
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= 1
12∙60 ∙ 1,53+90 ∙(51,32−0,75)2
= 1
12∙60 ∙ 3,38+90 ∙(2557,32)
= 230175,70 cm4
Ix2 = Ix3 = 1
12∙2,5 ∙ 863+215 ∙(51,32−( 1
2∙86+1,5))
2
= 1
12∙2,5 ∙ 863+215 ∙(6,82)2
= 142511,83 cm4
Ix4 = 1
12∙80∙ 2,53+200 ∙(38,68−1,25)2
= 1
12∙80∙ 15,63+200 ∙ 1401
= 280304,20 cm4
Ixtotal = Ix1 + Ix2 + Ix3 + Ix4
= 230175,70 + 142511,83 + 142511,83 + 280304,20
= 795503,56 cm4
Momen inersia arah-y (sumbu lemah penampang)
Iy = 1
12∙603∙ 1,5+ 1
12∙803 ∙ 2,5+{ 1
12∙ 86 ∙ 1,53}2+ {(86 ∙1,5 ) (19,32) }2
= 229817,46 cm4
Tegangan tarik pada web sebesar :
ft = P
7 tw
<σ y
= (17250 )1 /2
7×2,5<σ y
=492,86 kg/cm2<σ y=2475 kg /cm2
→ asumsikan tf = 2,5 cm = 25 mm
fb = 0,75P
t f 2
<σ y
= 0,75 ∙(17250)
2,52 < σ y
= 2070 < σ y=2475 kg /cm2
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A = 720 cm2 = 0,0720 m2
Q bs (profil) = A ∙ σbaja=0,0720 m2×7,850t
m3
= 0,5652 t/m’
Q footwalk = 0,1 t/m’+
Qtotal = 0,6652 t/m’
M max=Qtot ∙ l
2
8+¿ 49,52
¿ 0,6652× 112
8+¿ 49,52
= 59,58 tm’
= 59,58 x 105 kgcm
V = 12
×0,6652 ×11+16,43
= 20,09 ton
Wx = I x
y=795503,56
51,32 = 15500,85 cm3
σ x=Mw x
=59,58 ×105 kgcm15500,85 cm3
= 384,37 kg/cm2 < σ s=σ y
FK =
24751,5
= 1.650 kg/cm2
Tegangan pada profil
My = M x 1,10 x 0,1
= 59,58 x 1,10 x 0,1
= 6,5538 tm’
Wy = I y
x=229817,46
40 = 5745,44 cm3
σ y=M y
w y
=6,5538 ×105 kg cm5754,44 cm3
= 113,89 kg/cm2
σ=√σ x2+σ y
2+¿σ x σ y¿
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= √384,372+113,892+¿384,37 x 113,89¿
= 452,20 kg/cm2 < σ s=σ y
FK =
24751,5
= 1.650kg/cm2 OK
Profil Balok Crane yang dipakai aman untuk digunakan.
Cek lendutan pada profil
Δijin = L
600 =
11000600
= 18,33 mm = 1,833 cm
Lendutan akibat beban merata
Δ = 5 w L4
384 EI = 5 x 6,65 x11004
384 x2000000 x795503,56 = 0,08 cm
Lendutan akibat beban terpusat
Δ = pxa
24 E Ix [3xl2-4a2]=
17250 x10424 x2000000 x795503,56
[3 x 11002 – 4x1042]= 0,17
cm
Δtotal = 0,08 + 0,17
= 0,25 cm
= 0,25 cm < 1100600
= 1,83 cm → Profil Balok Crane aman digunakan.
Direncanakan kaki balok girder crane → panjang 1,5 m dengan tebal 3 cm
Cek Tahanan Geser
Vn = 0,6 . fy . Aw
Vn = 0,6 . 247,5 . (560x25)
Vn = 207,9 ton
Vu ≤ Ø Vn
20,09 ton ≤ 0,9 x 207,9 ton
20,09 ton ≤ 187,11 ton → OK
Perencanaan Dimensi Balok Crane Memanjang
Lh
< 25 7h
< 25 ; h = 35 cm
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Lb
< 65 7b
< 65 ; b = 35 cm
Di ambil ;
h = 40 cm Lh
= 7
0,4 = 17,5 < 25 OK
b = 40 cm Lb
= 7
0,4 = 17,5 < 65 OK
λ < 0,586 L
λ < 0,586 . 7
λ < 4,102 m’
Reaksi Perletakan
R = ½ x q x L2 + V
= ½ x 0,6652 x 72 + 16,43
= 32,73 ton
Dicoba dengan profil WF 400 x 400 x 13 x 21
λ = 1,50 m
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t2
r
t1
t2
B
H
r
t1 : 13 mm
t2 : 21 mm
r : 22 mm
A : 218,7 cm2
q : 172 kg/m
Ix : 66600 cm4
Iy : 22400 cm4
ix : 17,5 cm
iy : 10,1 cm
zx : 3330 cm3
zy : 1120 cm3
Cek Stabilitas
Tekuk lokal pada sayap (flens)
λ = 12
x Bf
2 x tf =
12
x 400
2x 21 = 4,76
λp = 0,38 √ Efy
= 0,38 √ 200000247,5
= 10,80( λ ≤ λp )
Tekuk lokal pada badan (web)
λ = Ht
= 40010
= 40,0
λp = 3,76 √ Efy
= 3,76 √ 200000247,5
= 106,88 ( λ ≤ λp )
(Penampang Balok Crane Memanjang Kompak) → OK
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Mmax = q total x L2
8 +
P x L4
= (0,172+0,6652) x72
8 +
32,73 x 74
= 62,41 tm
= 62,41 x 1,15
= 71,77 tm
Vmax = ½ x q x L + P
= ½ x(0,172+0,6652) x 7 + 32,73
= 35,66 ton
Cek kelangsingan kolom dan tegangan yang bekerja
λ = lk
imin =
70010,1
= 69,31 < 200
λc = λπ √ fy
E =
69,313,14
√ 247,5200000
= 0,78 ≤ 1,20
ω = 1,43
1,6−0,67 λ c =
1,431,6−0,67 (0 , 78) = 1,33
σ = ω x N
Ø x A +
MØ x zx
= 1,33 x 0
0,85 x218,7 +
717700,9 x3330
= 23,95 kg/cm2 < 2475 kg/cm2
Penampang balok WF cukup aman menerima gaya kombinasi dan tidak terjadi tekuk lentur
Kontrol terhadap lendutan
Δijin = L
600 =
7000600
= 11,67 mm
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Δ = 5w L4
384 EI = 5 x8,37 x 7004
384 x2000000 x 66600 = 0,15 cm
Lendutan akibat beban terpusat
Δ = pxa2
x3 xl 2−4 a2
24 E Ix=32730 x150
2 x 3 x7002 – 4 x1502
24 x2000000 x 66600 =0,94 cm
Δtotal = 0,15 + 0,94
= 1,09 cm
= 1,09 cm < 7000600
= 1,167 cm → Profil Balok Crane aman digunakan.
Mn = Mp
Zx = bf x tf x (d-tf) + ¼ x tw x (d-2tf)2
= 40 x 2,1 x (40-2,1) + ¼ x 1,3 x (40 – 2 x 2,1)2
= 3600,133 cm3
Mp = Zx x fy
= 3600,133 x 2475
= 8910329,175 kg/cm = 89,10 tm
Mu ≤ Ø Mn
39,63 tm ≤ 0,9 x 89,10 tm
71,77 tm ≤ 80,19 tm OK
Cek Tahanan Geser
Vn = 0,6 . fy . Aw
Vn = 0,6 . 247,5 . (358x21)
Vn = 111,64 ton
Vu ≤ Ø Vn
35,66 ton ≤ 0,9 x 111,64 ton
35,66 ton ≤ 100,48 ton → OK