Materi 3. Riveted Joint 2015

Ahmad Suudi Elemen Mesin I 2015

Riveted JOINTS

sambungan paku keling


Riveted JOINTS

• Sambungan rivet/keling digunakan untukmembuat sambungan permanen antara platseperti pada tanki, boiler, dsb.

• Fungsi rivet pada sebuah joint adalah untukmembuat sambungan yang memiliki kekuatan(strength) dan kerapatan (tightness).

• Kekuatan diperlukan untuk mencegah kegagalansambungan. Kerapatan diperlukan agarsambungan makin kuat dan mencegahkebocoran.

• Sambungan rivet/keling digunakan untukmembuat sambungan permanen antara platseperti pada tanki, boiler, dsb.

• Fungsi rivet pada sebuah joint adalah untukmembuat sambungan yang memiliki kekuatan(strength) dan kerapatan (tightness).

• Kekuatan diperlukan untuk mencegah kegagalansambungan. Kerapatan diperlukan agarsambungan makin kuat dan mencegahkebocoran.


Advantages of riveted joints:

Cheaper fabrication cost Low maintenance cost Dissimilar metals can also be joined, even non-

metallic joints are possible with riveted joints. Ease of riveting process.

Cheaper fabrication cost Low maintenance cost Dissimilar metals can also be joined, even non-

metallic joints are possible with riveted joints. Ease of riveting process.

http://www.indiastudychannel.com/resources/146267-Rivet-types-riveted-joints.aspx


Disadvantages of riveted joints:

Skilled workers required Leakage may be a problem for this type of

joints, but this is overcome by specialtechniques.

Skilled workers required Leakage may be a problem for this type of

joints, but this is overcome by specialtechniques.



Proses riveting / HEAD FORMING :


You know that the riveted joint is created by passing the stem of a rivetthrough holes in two plates as is shown in Figure 3.1(a). The creation of headby process of upsetting is shown in Figure 3.1(b). The upsetting of thecylindrical portion of the rivet can be done cold or hot. When diameter ofrivet is 12 mm or less, cold upsetting can be done. For larger diameters therivet is first heated to light red and inserted. The head forming immediatelyfollows. The rivet completely fills the hole in hot process. Yet it must beunderstood that due to subsequent cooling the length reduces and diameterdecreases. The reduction of length pulls the heads of rivet against plates andmakes the joint slightly stronger. The reduction of diameter creates clearancebetween the inside of the hole and the rivet. Such decrease in length anddiameter does not occur in cold worked rivet.


Rivet Heading Process(Riveting):

Usually clearance is considered as perfollowing:If diameter of rivet, d = 12 to 24 mm,Clearance, C = 1.5 mmIf diameter of rivet, d = 24 to 48 mm,Clearance, C = 2 mm

Usually clearance is considered as perfollowing:If diameter of rivet, d = 12 to 24 mm,Clearance, C = 1.5 mmIf diameter of rivet, d = 24 to 48 mm,Clearance, C = 2 mm

http://www.indiastudychannel.com/resources/146267-Rivet-types-riveted-joints.aspx


TYPES OF RIVET

• Rivets with counter sunk head as in Figure 3.2(b) andoval counter sunk rivets shown in Figure 3.2(c) are notas strong as button head rivets. They are used onlywhen protruding rivet heads are objectionable. Rivetjenis ini banyak dipakai pada pembuatan kapal.

• Rivets with counter sunk head as in Figure 3.2(b) andoval counter sunk rivets shown in Figure 3.2(c) are notas strong as button head rivets. They are used onlywhen protruding rivet heads are objectionable. Rivetjenis ini banyak dipakai pada pembuatan kapal.


TYPES OF RIVETS

• Pan heads and conical heads, Figures 3.2(d)and (e) are less frequently used and aredifficult to form.


TYPES OF RIVETS

• Tubular rivets, Figures 3.2(f) and (g) arespecial deviation from solid rivet shank. Theserivets are used in aircrafts.


Tipe-tipe HEADHEAD

Kepala rivet untuk penggunaan umum (diameter dibawah 12 mm). IS : 2155 – 1962Ahmad Suudi Elemen Mesin I 2015

Tipe-tipe HEADHEAD

Kepala rivet untuk penggunaan umum (diameter mulai 12 mm - 48 mm). IS : 1929 – 1961Ahmad Suudi Elemen Mesin I 2015

Tipe-tipe HEADHEAD

Kepala rivet untuk boiler (diameter mulai 12 mm - 48 mm). IS : 1928 – 1961Ahmad Suudi Elemen Mesin I 2015

Bahan RIVETRIVET

Bahan rivet umumnya adalah daribaja (low carbon steel). Untukkeperluan lain biasanya terbuat darikuningan, aluminum atau tembaga.

Bahan rivet umumnya adalah daribaja (low carbon steel). Untukkeperluan lain biasanya terbuat darikuningan, aluminum atau tembaga.IS-2100-1962 gives the steel rivet specifications which are used in boilers.


TYPES OF RIVETED JOINTSTYPES OF RIVETED JOINTS

The classification of riveted joints is based onfollowing :

(a)According to purpose,(b)According to position of plates connected,

and(c)According to arrangement of rivets.

The classification of riveted joints is based onfollowing :

(a)According to purpose,(b)According to position of plates connected,

and(c)According to arrangement of rivets.


Jenis sambungan RIVET

Ada dua jenis sambungan rivet (berdasar padabagaimana cara plat dihubungkan) :1. Lap Joint2. Butt Joint

Ada dua jenis sambungan rivet (berdasar padabagaimana cara plat dihubungkan) :1. Lap Joint2. Butt Joint


LapLap Joint : kedua plat ditumpuk dan kemudian di rivet


Single Riveted Lap joint


Ex. Double riveted lap joint

http://onlineeducations.net/rivets-and-riveted-joints/Ahmad Suudi Elemen Mesin I 2015

Double Riveted Lap Joint with Chain and Zig-ZagRiveting


ButtButt Joint : plat utama (main plate) diletakkan saling bersentuhandan plat cover (strap) diletakkan pada salah satu sisi atau kedua sisi dari platutama, baru kemudian di rivet bersama


Double Riveting With Double Cover and ChainRiveting

Double Riveted With Double Cover Plates andZig-Zag Joint


Lap joints are used for circumferential seams,and the stronger joint (butt joint) forlongitudinal joints.For high pressures in marine boilers, tripleriveting is frequently used.

Lap joints are used for circumferential seams,and the stronger joint (butt joint) forlongitudinal joints.For high pressures in marine boilers, tripleriveting is frequently used.


Caulking & Fullering

Caulking Tool Fullering Tool


Difference Between Caulking and Fullering

• Caulking: It is used to obtain

leak proof joints. This operation is carried

out by using narrow blunttool called caulking tool.

The thickness of tool isabout 5mm.

Surface finish obtained isless compared to fullering.

More risk of damaging theplates.

• Caulking: It is used to obtain

leak proof joints. This operation is carried

out by using narrow blunttool called caulking tool.

The thickness of tool isabout 5mm.

Surface finish obtained isless compared to fullering.

More risk of damaging theplates.

Caulking Tool


Difference Between Caulking and Fullering

• Fullering: It is used to obtain leak

proof joints. It is carried out by using

fullering tools.The thickness of tool is

equal to the thickness ofthe plate. It is gives clean surface

finish. Less risk of damaging the

plates.

• Fullering: It is used to obtain leak

proof joints. It is carried out by using

fullering tools.The thickness of tool is

equal to the thickness ofthe plate. It is gives clean surface

finish. Less risk of damaging the

plates.Fullering Tool

http://mechanizer.info/blog/2014/03/13/difference-between-caulking-and-fullering/


Istilah teknisteknis• Pitch : jarak antara pusat satu rivet ke pusat rivet

lain yang terdekat.

• Biasanya dinotasikan dengan : p


Istilah teknisteknis• Diagonal pitch : jarak antara pusat-pusat rivet

yang saling berdekatan secara zig-zag.• Biasanya dinotasikan dengan pd

• Diagonal pitch : jarak antara pusat-pusat rivetyang saling berdekatan secara zig-zag.

• Biasanya dinotasikan dengan pd


Istilah teknisteknis• Back pitch : jarak antar kolom pada

sambungan rivet.• Biasanya dinotasikan dengan pb

• Back pitch : jarak antar kolom padasambungan rivet.

• Biasanya dinotasikan dengan pb


Istilah teknisteknis

• Margin : jarak antara pusat lubang rivet ke sisiterdekat dari plat.

• Biasanya dinotasikan dengan m



Remember

Tenggelamnya Kapal Titanic ?Apa penyebabnya ?


Iron vs Steel Rivets — Why the Titanic Sank

• The article In Weak Rivets, a Possible Key toTianic’s Doom, lays out the accumulatingevidence that it was the use of cheaper,weaker, iron rivets, over stronger steel rivetsthat allowed the ice burg to to rip suchgigantic gashes in the hull of the great ship.

• The article In Weak Rivets, a Possible Key toTianic’s Doom, lays out the accumulatingevidence that it was the use of cheaper,weaker, iron rivets, over stronger steel rivetsthat allowed the ice burg to to rip suchgigantic gashes in the hull of the great ship.


Samples of four different types of rivets recovered from the Titanic. While some shipsof the time were built entirely with steel rivets, the Titanic used a mix of steel and ironrivets. In the bow, where the Titanic hit the iceberg, weaker iron rivets were used.


To test the theory of weak rivets on the Titanic, Chris Topp, a blacksmith in Yorkshire,England, recreated one of the Titanic’s double-riveted hull joints.


Stresses similar to what the Titanic experienced in its collision with the iceberg wereapplied to the joint, and the top of one of the rivets popped off, at a load only 60percent of what a good quality rivet should have withstood.


The small “button” on the inside of the rivet head was similar in shape to broken rivetsrecovered from the Titanic wreckage.



Kegagalan sambungan RIVET

• Robek pada salah satu sisi plat (tearing of theplate at an edge)

• Robek pada plat melintasi baris rivet (tearingof the plate across a row of rivets)

• Bergesernya rivet (shearing of the rivets)• Hancurnya/rusak rivet (crushing of the rivets)

• Robek pada salah satu sisi plat (tearing of theplate at an edge)

• Robek pada plat melintasi baris rivet (tearingof the plate across a row of rivets)

• Bergesernya rivet (shearing of the rivets)• Hancurnya/rusak rivet (crushing of the rivets)


Tearing of the plate at an edge

• Dapat dihindari dengancara membuat margin,m = 1,5 d.

• d = diameter rivet

• Dapat dihindari dengancara membuat margin,m = 1,5 d.

• d = diameter rivet


Tearing of the plate across a row ofrivets• Akibat gaya tarik yang

bekerja pada mainplate, maka cover plateatau main plate dapatmengalami robekan.

• Akibat gaya tarik yangbekerja pada mainplate, maka cover plateatau main plate dapatmengalami robekan.


Tearing Resistance of the plate

Luas area robekan per panjang pitch :At = (p – d)t

Tearing Resistance Plat: Pt = σijin.At = σijin (p – d)t

p : pitch rivetd : diameter rivett : tebal platσijin : tegangan tarik ijin bahan plat

Luas area robekan per panjang pitch :At = (p – d)t

Tearing Resistance Plat: Pt = σijin.At = σijin (p – d)t

p : pitch rivetd : diameter rivett : tebal platσijin : tegangan tarik ijin bahan plat


Shearing of the rivets


Shearing of the rivets

Single shear Double shear


Jika d = diameter rivet, τijin = tegangan geser ijinbahan rivet, n = jumlah rivet per panjang pitch, maka

Luas area geseran :

)(4

875,1

)(4

2

)(4

2

2

2

IBRsesuaigandageserandxA

gandageseranuntukteoritisdxA

tunggalgeseranuntukdA

s

s

s

)(4

875,1

)(4

2

)(4

2

2

2

IBRsesuaigandageserandxA

gandageseranuntukteoritisdxA

tunggalgeseranuntukdA

s

s

s


Shearing Resistance Rivet:

nxdxP

nxdxP

nxdP

ijins

ijins

ijins

2

2

2

4875,1

42

4

Single shear

Shearing Resistance Rivet

nxdxP

nxdxP

nxdP

ijins

ijins

ijins

2

2

2

4875,1

42

4

Double shearteoritis

Double shearIBR


Crushing of the rivets


Jika d = diameter rivet, t = tebal plat, fc = tegangancrush ijin bahan rivet, n = jumlah rivet per panjangpitch, maka

Luas area crushing per rivet :Ac = d.tSehingga total crushing area = n.d.t

Crushing Resistance :Pc = n.d.t.fc

Luas area crushing per rivet :Ac = d.tSehingga total crushing area = n.d.t

Crushing Resistance :Pc = n.d.t.fc


Kekuatan Sambungan RIVET

Kekuatan suatu sambungan dapat didefinisikansebagai gaya maksimum yang dapatditransmisikan tanpa terjadi kegagalansambungan.

Pt, Ps dan Pc adalah tarikan yang dibutuhkanuntuk merobek plat, menggeser rivet danmenekuk rivet.

Kekuatan suatu sambungan dapat didefinisikansebagai gaya maksimum yang dapatditransmisikan tanpa terjadi kegagalansambungan.

Pt, Ps dan Pc adalah tarikan yang dibutuhkanuntuk merobek plat, menggeser rivet danmenekuk rivet.


Efisiensi Sambungan RIVET

Efisiensi Sambungan RIVET adalah rasiokekuatan sambungan terhadap kekuatan plattanpa rivet (plat utuh).

Kekuatan sambuangan rivet diambil nilai terkecildari Pt, Ps dan Pc.

Kekuatan plat tanpa rivet : P = p x t x ft

Efisiensi Sambungan RIVET adalah rasiokekuatan sambungan terhadap kekuatan plattanpa rivet (plat utuh).

Kekuatan sambuangan rivet diambil nilai terkecildari Pt, Ps dan Pc.

Kekuatan plat tanpa rivet : P = p x t x ft

t

cst

ftp

PPPofleastefisiensi

..

,,


Tabel efisiensi sambungan rivet untukboiler menurut Indian Boiler Regulations

Lap joint Efisiensi (%) Butt joint (doublestrap)

Efisiensi (%)

Single riveted 45 - 60 Single riveted 55 – 60

Double riveted 63 - 70 Double riveted 70 – 83

Triple riveted 72 - 80 Triple riveted (5 rivetsper pitch)

80 – 90Triple riveted 72 - 80 Triple riveted (5 rivetsper pitch)

80 – 90

Quadruple riveted 85 – 94


Documents

Materi 3. Riveted Joint 2015