STRUKTUR BAJA I rhituga Samuga Las
Samuga Las Samuga as ada dua macam, yaitu: - as tumpu - as sudut Tgaga: σ as σ 0, 6σ
a Las Tumpu: s s sa Utuk s s ---- ta as tumpu (a) s Utuk s s ----- ta as tumpu (a) s mi as a ---- pajag as to r a σ σ as
Cotoh Dua pat aka disamug dga as umr tuk tumpu, ukura pat ukura pat 0/60 Mrima gaya tarik sjajar sumu pat ssar 000 σ 400 / Kotro kkuata as s s 0 mm 60 mm 4
ysaia: as a r t a 0 mm 60 mm t r a 60 0 0 mm σ < as 000 x 000 / 400 / Jadi as cukup kuat maha gaya yag krja pada pat yag disamug ts 5
Cotoh Suah pat ta (s) 8 mm, 00 mm, disamugka pada tiag aja dari profi DIN dga as tumpu Samuga ts maha gaya 000 sjauh 50 mm dari as (spt gr disampig) s σ 400 / 0,6σ 840 / Kotro kkkuata as 6
ysaia Ta as (a) s 0,8 r t 00 mm 0 r a 0 (x0,8) 7,6 idahka gaya pada kduduka as timu mom M da gaya gsr M 000 x 5 5000 σ M W as 6 a 0 6 x0, 8x0 W as 7
σ 5000 0 5 / < 400 / x 4 x D S I dimaa: D ; S S x as a as ; I I x as s ( a) x S x 4 S x (5 x 0,8 ) x 7,5 90 I x h dimaa: a h 8
I x a I x 800 x 0, 8 x0 4 S a I x x 000 x 90 0,8 x 800 4 694,44 / < ok Jadi as cukup kuat maha gaya yag krja ts 9
Las Sudut: - Arah gaya // as idag rtak / s/t s a 4500 s a ta as a s si 45 o 0,707s s ta pat pajag kaki as Bidag rtak utk as sudut yag diai gaya dga arah // as, aka mmuat sudut 45 o dga kaki as 0
Las Las dipasag pada dua agia Gaya aka ditaha oh as atas da awah ssar da x x
gs gs 0,6σ gs gs r a a a 0,707 s 0,707 s dimaa: pajag as to r pajag as ruto a ta as ot: pajag as mi ( mi ) 40 mm pajag as mak ( mak ) 40 a 8,8 s
Cotoh 0/00 Dikt: Kost spt gamar Gaya 000 ; as dipasag pada dua muka σ 400 / ; 0,6σ Hitug pajag as 840 / ysaia: s 0 mm ; a 0,707s 0,707 00 mm 0 ; ½ 0 ½ 000 ; r
a 0, 707 gs gs gs 000 840 gs,9 0,707,9,68 r a,68 x 0,707,804 4 Jadi pajag as 40 mm 4
Cotoh 4 0/00 75750 - ysaia: x y d Dikt: Kost spt gr Gaya 500 ; as pada dua muka B y d x σ 400 / 0,6σ 840 / Hitug pajag as Dari ta profi, utk L 75750 didapat: 75 mm 7,5 ; d 0 mm, 5
d a 0,707d a 0,707x 0,707 7,5, 5,9 Σ M B 0 0 500 x, 7,5 77 Σ H 0 500 0 77 76 6
7 7 ami a a r r r gs gs gs 4 4,6 ) (x 0,707,4,4 0,707 0,877 0,707 0,877 0,707 0,877 840 77 840 mi ami <
,099 gs gs r,099 0,707 ami gs a 76 840,969 a,969 (x0,707) 5,09 ami 6 0,707 0,707 840,099 Rsum: ajag as atas 4 ajag as awah 6 8
Skt gamar samuga 0/00 40 mm 75750 0 mm y as sudut 5,9 mm, mm 00 mm x 60 mm as sudut y 9
0 0 Las dipasag pada tiga agia Las dipasag pada tiga agia B A a a a r 0 0 ) ( 0 M B Σ 0 0 ) ( 0 M A Σ
Cotoh 5 ysaia: 0/00 s 0 mm ; a 0,707s 0,707 00 mm 0 ; ½ 5 Dikt: Kost spt gr Gaya 0000 ; as pada tiga muka σ 400 / 0,6σ 840 / Hitug pajag as
Las ujug dipasag spajag r 0 r -a 0 - x 0,707 7,879 gs a 7,879 x 0,707 x 840 4680 Σ H 0 0 (0 000 4 680 ) 660
,67 gs gs r r,67 0,707 gs a 6,6 ami a 660 840 0,707 0,707 4,479 7 4,479 Rsum: ajag as 7 ajag as 0 840 > mi,67 4 (x0,707) ok
Cotoh 6 0/00 / / B ysaia: 75750 - Dikt: Kost spt gr Gaya 7500 ; as pada tiga muka σ 400 / 0,6σ 840 / Hitug pajag as Dari ta profi, utk L 75750 didapat: 75 mm 7,5 ; d 0 mm, 4
d a 0,707d a 0,707x 0,707 7,5, 5,9 ajag as r diami r 7,5 r -a 7,5 - x 0,707 5,79 ami a 5,79 x 0,707 x 840 95 840 5
6 6 M B 6,5 7,5 98,5 5 575 7,5 x 7,5 x 95 x, 7500 0 0 Σ H,5 69,5 6 95 7500 0 0 Σ
7 7 ami a a r r r gs gs gs 4 4,5 ) (x 0,707,0,0 0,707 0,79 0,707 0,79 0,707 0,79 840 6,5 840 mi ami <
8 8 a a r r gs gs gs 9 8,9 ) (x 0,707 6,8 6,8 0,707 4,96 0,707 4,96 0,707 4,96 840 69,5 840 ami
Skt gamar samuga 0/00 40 mm 75750 0 mm as sudut 75 mm 5,9 mm, mm 00 mm 90 mm as sudut Rsum: ajag as 4 9 7,5 9
- Arah gaya as idag rtak / s s 6750 Bidag rtak utk as sudut yag diai gaya dga arah as, aka mmtuk sudut 67½ o dga kaki as Utuk mmprmudah daam prhituga, diami sudut 45 o 0
as atas a as awah s a 4500 D / s N Gaya as, aka ditaha oh as sudut atas da awah ssar da Utuk s s, maka ½ Gaya / kja pada titik rat idag rtak ½ // Gaya gsr D ½ si 45 o Gaya orma N ½ si 45 o D N
σ σ i D gs N tr σ σ σ 0,6σ gs uas idag gsr uas idag rtak gs a Dimaa: a ta as s si 45 o 0,707s s ta pat yag disamug pajag as to r a r pajag as ruto tr uas idag tarik uas idag rtak
Utuk s Utuk s s (ta pat tidak sama) (ta pat tidak sama) s s s gs 0,707 s a a a r gs gs 0,707 s a a a r gs
4 4 σ σ tr a tr σ σ tr a tr σ σ σ σ i i
Cotoh 7 8/00 s 0/00 Dikt: Kost spt gr Gaya 5000 ; Las sudut sar pat ysaia: σ 400 / 0,6σ 840 / Kotro kkuata as Ta pat tidak sama s 8 mm 0,8 a 0,707 x 0,8 0,566 s 0 mm a 0,707 x 0,707 00 mm 0 r r 0 r - a 0 x 0,566 8,0 r - a 0 x 0,707 7,879 5
6 6 H s s s 778 5000 0 x 5000 0,8 0,8 Σ 47 47 8,0x0,566 tr gs σ Las atas Las atas σ σ σ < 946 (47) 47 i
Las awah σ gs tr 778 7,879x0,707 499 499 σ σ 499 (499) 998 < σ i Jadi as cukup kuat 7