ship structural elements (guverte i uygulama sunumu)

8/12/2019 Ship Structural Elements (Guverte I Uygulama Sunumu)

1/38

Ship Structural Elements

Burak Acar


2/38

Ships Structures are unique for a variety ofreasons. For example:

Ships are BIG!

Ships see a variety of dynamic and random

loads

The shape is optimized for reasons otherthan loading.

What are they optimized for?

Ships operate in a wide variety of

environments.


3/38

Ship Structural Loads

Up until now we have used Resultant(single point) Forces through G (s) and B (FB)

Stern Bow


4/38

LOAD APPLIED

LOAD APPLIED

Recall M=F x D!


5/38

If the beam sags, the top fibers are incompression and the bottom fibers are in

tension.

Tension

Compression


6/38

Buoyant force is greater at wave crests.

If the wave crest is at the bow and stern, the

vessel is said to be sagging. The net effect isthat the middle has less support.

Sagging

Trough Amidships


7/38

If sagging loads get too large...


8/38

Hogging - Buoyancy Support in the Middle


9/38

Sagging - buoyancy support at the ends


10/38

Titanic

The ship in still water. The water supports the ship's weightevenly along the length. Notice that discontinuities cause stress risers

even in still water -- for example, around the aft expansion joint

(look at the area of lighter blue).


11/38

Titanic

The ship would have been at when the first three compartments

flooded. This imbalance between the weight and buoyancy causes

the bow to droop downward . Stresses in the bow are generally higher

than they were in the still condition. Notice that the increase in

stresses around the forward expansion joint causes a light blue peak.


12/38

Titanic

The condition of the ship just before sinking.

The first six compartments are flooded, and the stern has risen

out of the water. This huge imbalance causes severe bending of

the hull in the midship region.


13/38

Titanic

This huge imbalance causes severe bending of the

hull in the midship region. This large red area surrounds

the aft expansion joint, while a smaller red area occurs

around the forward expansion joint. During the sinking,

the forward expansion joint opened up sufficiently tobreak the two stack stays which crossed it. The hull

broke into three pieces. The middle piece was a 60-foot

long section centered about the aft expansion joint. This

matches the location of the large red area in the image.


14/38

Titanic

Along with the remaining windows and glass, the large gap

in the center of the photo is one of Titanic's two expansion joints.

These joints were a structural addition to accommodate for

mechanical stresses on the ship.


15/38

A ship structure usually consists of a network of

frames and plates.

Frames consist of large members running both

longitudinally and transversely. Think picture frame.

Plating is attached to the frame providingtransverse and longitudinal strength. Think

dinner plate.


16/38


17/38

Keel: Longitudinal center plane girder along

ship bottom Backbone .

Plating: Thin skin which resists the hydrostatic

pressure.

Frame: Transverse member from keel to deck.

Floor: Deep frames from keel to turn of the

bilge.


18/38

Longitudinals: Parallel to keel on ship

bottom, provide longitudinal strength.

Stringers: Parallel to keel on sides of

ship, also provide longitudinal strength


19/38


20/38

frameplate


21/38

Longitudinal Framing

Consists of closely spaced longitudinals and

widely spaced web frames.

Longitudinal framing resists longitudinal

bending stresses.

Side plating is thin, primarily designed to

keep the water out.


22/38


23/38


24/38

Double Bottoms

Double bottoms are two watertight bottomswith a void (air) space in between.

They are strong and can withstand the

upward pressure of the sea in addition tothe bending stresses.

Provide a space for storing fuel oil, fresh

water (not potable), and salt water ballast.

Withstand U/W damage better, but rust

easier.


25/38

Double Bottom

Menhole


26/38

OTHER PARTS OF SHIPS...


27/38

Locations and Directions Aboard Ship


28/38

Bulkheads and Decks


29/38

External Parts of the Hull


30/38


31/38


32/38

Boru Devreleri


33/38

Tanklar


34/38

Ambarlar


35/38

Ambarlar ve Ambar Kapaklar


36/38

Makine Dairesi


37/38

Makine Dairesi


38/38

ship structural elements (guverte i uygulama sunumu)

Documents