Course project structural midship frame of a bulk carrier introduction. Structural midsection frame of a dry cargo ship Structural midsection frame of a dry cargo ship

Initial data:

L = 96.5m – design length;

B = 15.8m – width;

Н = 10.2 m – side height;

T = 7.1 m – draft;

R = 1.20m – cheekbone rounding radius;

Sfl = 9.0mm – flor thickness;

? No. 22b – strip-bulb frame;

? No. 18a – stripe-bulb beams;

Sdd = 9.0 mm – thickness of the double bottom flooring;

Sxh = 12×450mm – carling wall;

Sxb = 14×220mm – carling belt;

Sp = 11mm – thickness of the deck;

Sb = 12mm – thickness of the outer skin of the side;

Sdn = 14mm – bottom thickness.

1. Introduction

The hull of a moving ship can be subject to constant and random
loads.

Constant loads acting during the entire period of operation -
this is the weight of the hull, superstructures, ship machinery and accepted cargo, force
maintenance and resistance of water to the movement of the vessel. The forces of the ship's weight and
hydrostatic support forces are directed in opposite directions
and balance each other. These forces are distributed along the length of the vessel
unevenly. So in the holds located in the middle part of the ship, the cargo
more than in the end holds, especially in the first. Fully loaded
Forepeak and afterpeak general cargo vessels are often empty. Main
the engine occupies a small area in the engine room, but its mass
significant. However, the total mass of machinery in the engine room is usually
less than the mass of cargo in a fully loaded hold. Maintaining forces
are also unevenly distributed throughout the ship. Their intensity depends on
the magnitude of the displaced volumes, which gradually decrease from the middle
of the vessel to the extremities when the vessel is sailing in calm water and continuously
change under conditions of excitement.

Random loads act on the body for a period of time
period of time and occur when waves strike, a ship runs aground,
ship collision.

To simplify calculations, the operating loads are conventionally divided into two
categories: causing general bending of the body or local bending of individual
its elements.

In calm water, the nature of the general deformation of the hull usually remains unchanged
during the entire voyage, if the distribution of main cargo or ballast
permanent. Only the degree of curvature of the body in the DP changes as
fuel consumption and reserves. On excitement, general deformation of the hull
changes cyclically many times: the deflection of the body alternates with
inflection. Housing strength is ensured with repeatability in mind
loads The greatest bending moment acts in the area of the middle
vessel.

The ability of the body to withstand loads acting on its individual
overlaps and connections, determines local strength. Among local loads
release hydrostatic pressure during emergency flooding of compartments,
concentrated and distributed forces when receiving and removing loads in
area of lifting devices, reaction of keel blocks when placed in
dock, concentrated forces during mooring and towing, compression forces
hulls with ice during ice navigation of the vessel.

In fact, the stresses in the housing structures are calculated as
algebraic sum of stresses from general bending and local loads.

2. Selection of dialing system and body material.

On relatively small ships (up to 100 meters in length), the value
bending moment from the overall longitudinal bending of the body is relatively
small. The determining factors for such vessels are local loads:
load pressure, water pressure, wave impacts, ice impacts and others.

The dimensions of the main hull connections of such vessels are determined mainly from
conditions for ensuring local strength, but they are sufficient to ensure
overall strength of the vessel. Overall longitudinal strength of ships up to 100 in length
meters is provided with relatively small thicknesses of the outer
plating and decking of the upper deck.

Local strength of the hull is easily ensured with a transverse system
set of floors. With a transverse dialing system, the main connections
located across the ship. Bottom floor connections, with the exception of
longitudinal connections far apart from each other consist of continuous or
bracket floors on each practical frame; airborne communications
the floors consist of frames with a normal distance from each other;
The deck ties consist of beams.

The transverse dialing system is relatively simple and economical.

Based on the data presented, in this work we believe that the corpus is composed
according to the transverse dialing system.

For ships of short length (up to 120m), steel is usually used
carbon shipbuilding grade VSt3spII with yield strength ReH =
235 MPa. Since L = 96.5m, in this work we assume that for
In the construction of the vessel, steel of this particular size will be used.

3. Calculation of the main connections of the body

3.1 Vertical keel

The height of the vertical keel is determined by the empirical formula:

hвк = 0.0078L + 0.3 = 0.0078*96.5 + 0.3 = 1.053m,

where L is the design length of the vessel, m.

We accept hвк = 1m = 1000mm.

The thickness of the vertical keel is determined by the formula:

hvk 235 1000
235

Svk = ((*((= ((*((= 12.5mm,

80 ReH 80
235

where ReH is the yield strength of steel, which is accepted for construction
of this vessel, m.

According to sheets produced in industry, we accept the thickness
vertical keel Svk = 13.0 mm.

3.2 Spatzia

Spacing is determined by the formula:

a = 0.002L + 0.48 = 0.002*96.5 + 0.48 = 0.67m.

We accept spacing a = 700mm.

3.3 Bottom stringers

The number of bottom stringers is determined depending on the width of the vessel.

Based on the fact that the vessel is built using a transverse system and B = 15.8 m
(i.e. 8(B(16), we place one bottom stringer from each
sides.

The thickness of the bottom stringer Sst is equal to the thickness of the floor Sst = Sfl = 9.0 mm.

On flora with a height of more than 900 mm, stiffening ribs must be installed
with a thickness of at least 0.8 Sfl and a height of at least 10 rib thicknesses, but not
more than 90mm.

We accept Sрж =8mm.

With a transverse recruitment system, floor stiffeners are installed
so that the unsupported span of the flora does not exceed 1.5 m, therefore in
In this work, the bottom stringer is displaced. One of the stiffeners
located directly below the end of the zygomatic book.

To access the double-bottom space, it is necessary to make holes in the flora.
The minimum height of the manhole is 500mm, the minimum length is 500mm. Lazy
located in the middle of the height of the flora. Distance of the manhole edge from
vertical keel is 0.5 times the height of the vertical keel. Distance
the edges of the manhole from the bottom stringer and stiffening ribs, the flora is
0.25 flora height in this section.

The double-bottom space is used to receive ballast and technical
water. In addition, when docking the vessel, the tightness is checked
double bottom compartments filled with water. To remove air from the compartments
double bottom into the atmosphere there are air pipes going out to
upper deck In the upper part of the flora at the second bottom flooring for exit
air when filling the double bottom compartment with liquid are provided
semicircular cutouts with a diameter of 50mm. To be able to dry the compartment during
The floras have similar cutouts in the bottom trim.

3.5 Zygomatic arch

The zygomatic bracket serves to connect the frame with the floor.

Height of the zygoma:

hkn = 0.1lshp,

where lshp is the span of the frame, which is determined by the formula:

lshп = Н – hвк = 10.2 – 1.0 = 9.2 m.

Then we get the value of the height of the zygomatic book:

hkn = 0.1*9.2 = 0.92m = 920mm.

We accept hkn = 900mm.

Width of the zygomatic book:

bsk kn = hsk kn + hshp = 900 + 220 = 1120mm,

hshp is the height of the frame, determined by the frame number of the strip-bulb.

3.6 Double bottom sheet

On modern ships, the double-bottom sheet is used in the holds
horizontal.

Double bottom sheet width:

bml = bsk kn + 40 = 1120 + 40 = 1160mm.

The double-bottom sheet is subject to intense corrosion, so its thickness
accepted 1mm thicker than other sheets of second bottom flooring

Sml = Sdd + 1.0 = 9 + 1 = 10mm.

3.7 Beam book

The beam bracket has two identical legs C, the size of which can
be accepted:

C = 1.5hbeams = 1.5*180 = 270mm,

where hbeam is the height of the beam according to the profile number.

The thickness of the beam bracket is equal to the thickness of the beam wall Sкн = 8 mm.

Since the leg of the beam bracket is C (250mm, a flange is provided along the free
edge of the book to ensure its rigidity - bent free edge
at an angle of ~90 (width 10 thicknesses of the bracket, i.e. 80mm.

3.8 External cladding

Shearstrek is a reinforced side sheathing sheet.

Sheartrack width bsh (0.1N, m and can be taken in the range from 500 to
2000mm. We accept bsh = 1100mm.

The thickness of the shearstrake Ssh is assumed to be equal to the thickness of the outer skin of the side
or deck flooring, whichever is larger. We accept Ssh = 12mm.

The horizontal keel is a reinforced bottom plating sheet.

The width of the horizontal keel is determined depending on the length of the vessel.
For a vessel length L (80m, the width of the horizontal keel is determined by
formula:

bgk =0.004L + 0.9 = 0.004*96.5 + 0.9 = 1290mm.

We accept bgk = 1300mm.

The thickness of the horizontal keel (mm) must be greater than the thickness of the sheets
bottom plating in the middle part of the vessel by the amount

(S = 0.03L + 0.6 = 0.03*96.5 + 0.6 = 3.5mm,

but this value cannot exceed 3 mm, so we accept (S = 3 mm and
accordingly Sgk = 17 mm.

3.9 Deck flooring

Since the thickness of the side plating is greater than the thickness of the deck flooring, the outermost
the decking sheet adjacent to the side must be reinforced, i.e. necessary
determine the dimensions of the deck stringer.

The width of the deck stringer is equal to the width of the horizontal keel bps =
bgk = 1300mm.

The thickness of the deck stringer is assumed to be equal to the thickness of the side plating
Sps = Sb = 12mm.

Note: All necessary constructions have been completed, and all necessary
dimensions are indicated in the drawing attached to the calculation and explanatory
note.

Literature:

Fried E.G. Structure of the vessel - L.: Shipbuilding, 1969.

Smirnov N.G. Theory and structure of the vessel - M.: Transport, 1992.

R. Dopatka, A. Perepechko Book about ships - L.: Shipbuilding, 1981.

Midship frame of a bulk carrier using a transverse frame system

Midship frame is a section of the hull of a ship or other watercraft with a vertical transverse plane, located at half the length between the perpendiculars of the theoretical drawing of the ship. Included in the number of basic points, lines and planes of a theoretical drawing. May not coincide with the widest section of the housing. The actual frame is usually installed in this plane. TRANSVERSE SYSTEM A ship hull frame in which the main continuous connections are located in the transverse plane (frames, beams). The purpose of these connections is to provide lateral strength of the vessel and transfer local load to the rigid contour of the vessel (bottom, sides, deck, etc.). S.N.P. ships were used in wooden shipbuilding. In modern conditions, it has been preserved on small military vessels and on most civilian vessels, both sea and river, as well as at the ends of ships recruited according to the longitudinal recruitment system.

Midship frame of a bulk carrier using a mixed system of framing

The midship frame is a section of the hull of a ship or other watercraft with a vertical transverse plane, located at half the length between the perpendiculars of the theoretical drawing of the ship. Included in the number of basic points, lines and planes of a theoretical drawing. May not coincide with the widest section of the housing. The actual frame is usually installed in this plane.

MIXED SET-UP SYSTEM is a ship's hull set-up, in which the parts of the hull furthest from the neutral axis (bottom, upper deck) have a purely longitudinal set-up system, while other parts of the hull (sides, remaining decks) have a purely transverse set-up system. This framing system, which is the most advantageous in terms of hull weight, is widely used in military shipbuilding. The first military vessels built according to the longitudinal-transverse system were our Marat-class battleships.

The main dimensions of the vessel affect the technical and operational characteristics of the product. The construction of a boat always begins with measurements, determining dimensions and drawing up a theoretical drawing of the vessel. The listed characteristics give a more complete understanding of the contours and their characteristics.

Key Dimensions

The main dimensions of a vessel include 4 main dimensions: length, width, side height and draft level.

Once these values have been reliably determined, the owner or designer can make decisions regarding a variety of operational tasks: the method of mooring at the pier, the ability to move in shallow waters, the level of lifting capacity. Today, several values of the listed quantities are distinguished:

The largest length dimensions in design documents are designated Lnb. Defined as the distance between the outermost points of the structure when measured along the body;

The main dimensions of the vessel affect the technical and operational characteristics of the product

length in relation to the design waterline of the vessel (DWL). First, let's look at what a ship's waterline is - this is the line of contact between the water and the hull of the boat. Novice designers and many owners have a question, what is KVL? KVL is the distance between the farthest points of the hull, which uses the water surface for measurements at the maximum load on the vessel (the amount of weight and the percentage of the maximum load capacity may differ);
the greatest width is marked using Vnb; it is measured in the area of the maximum width of the vessel. Measurements are taken along the outer edges;
the width along the waterline is defined as the distance between the end points along the width along the waterline;
height at midsection. First you need to define what is midsection? The midship of a ship is a plane located across the boat and has a vertical direction that runs in the center of the length of the boat. Mostly in the drawings, the midsection is the symbol H. To measure it, a measurement is used from the keel part (lowest point) to the top of the side;
the height of the part of the side above the water (F). Measured from the waterline to the top of the side. Mostly the freeboard is determined at the midsection, but the information is supplemented with values at the bow and stern;
average draft values (T) are defined as the depth of the boat into the water with increasing pressure. Most often, the midship from the vertical line to the lower keel mark is used for this.

Main dimensions

In addition to the key values, the theoretical drawing of the ship's hull often contains designations of dimensions:

length of the vessel, including protruding elements of the stems;
overall draft is the measurement from the vertical line to the lower part of the vessel (to the PM spur or other elements);

Main body sections

width in dimensions, determined by the protrusions of the sides or by the fenders;
overall height is the measurement from the very bottom to the top of the vessel.

There are values given in exact numbers, but the body is often characterized by additional dimensions that appear as a ratio of values. Frequent values are relationships:

length and width along the immersion line of the boat (L/B), allows you to determine the propulsion of the structure, since with an increase in L/B the vessel becomes faster, provided that it is of a displacement type. It also determines stability; accordingly, with a decrease in L/B and the same length, the vessel becomes more stable;
width along the design waterline to draft (W/D). The indicator provides data on propulsion, seaworthiness and structural stability. As the ratio increases, the vessel becomes more stable, but the ability to maintain the same speed when waves appear on the water decreases. Narrow, deeply submerged hulls withstand waves more easily;
maximum length and side height of the vessel in the midsection area (Lnb/H). The rigidity of the bottom and its strength are described. The lower this indicator, the greater the strength of the body;
absolute depth of side to draft capacity (H/T). Shows the boat's buoyancy reserve. As this indicator increases, the reserve becomes larger; accordingly, the vessel is able to withstand a greater load without the risk of waves entering the cockpit.

Vessel hull geometry

What is a theoretical drawing?

A theoretical drawing is a drawing on a sheet of paper that describes the complex structure of the body along the surface. To fully understand the structure, 3 projections are used at perpendicular intersection. The drawing shows the joints of the sheathing on the outside with intersecting planes; there are special rules in this regard. To build a ship, 3 planes are required: the main one, the midship frame, and the diametrical one. Main sections of the ship's hull:

center plane (DP) of the vessel. The ship's DP is a plane that runs vertically and divides the entire hull into 2 equal parts along the length;
the main plane (BP) of the ship is a view of the ship from below, the coordinate plane is strictly horizontal;
midsection plane. The last important plane of the midship frame runs vertically across the length. Many people do not know that this structure of the drawing allows you to see the type of sides, the type of frames and the structure of the cockpit.

To obtain all three types of theoretical drawing, it is necessary to present a section of the vessel along the listed trajectories, parallel to the three planes. The side view projection shows traces of the body being cut in one plane exactly in the center along its entire length. Such marks are called buttocks. The second section is made with equidistant horizontal planes below the waterline (half-latitude). Traces from the bottom cut provide information about the hull.

All lines of the drawing on one projection have a curved shape, and on the rest they are presented smoothly. Frames, when viewed from the side or half-latitude, will be presented only in the form of lines, but in fact they are always made in a curvilinear manner. The waterline has a straight view from the side and on the “hull” section, and the buttocks are on the hull and half-breadth.
Theoretical drawing of the vessel

The drawings are made from the point of view of the symmetry of the port side; accordingly, the waterline of the port side is displayed at half latitude. On the right side the hull is outlined with the contours of the bow frames, and on the left - the stern, so as not to clutter up each drawing.

What are completeness factors?

The total displacement coefficient is the most important parameter of the drawing, since it reflects the volume of water that the hull will displace when submerged to the waterline. Displacement has a volumetric characteristic and allows you to determine the dimensions of the vessel, the capacity of the structure and seaworthiness.

Displacement is not a static quantity, because it depends on the level of load on the vessel; accordingly, some varieties are distinguished:

complete. It is assumed that there is a full tank of fuel, the required amount of water for drinking, crew and provisions on board;
empty - this is the ability to push out water with an engine and supplies installed on board, but in the absence of fuel, personal belongings, provisions and people;
measurements. There are sails and supplies on board, but no crew, fuel or other things. Used only for sailing boats.

The displacement value in the drawings is described by the letter V and measured in m3. Used to determine the characteristics of the vessel's fullness coefficients. There is some difference from weight displacement, since the latter indicator describes the ship's cargo and is calculated in tons, and the ship's fullness coefficients take into account the density of water. Calculations are carried out using the formula D = p*V, where p is the reference density of water.

1. Selecting a slab set system, grade and category of steel, spacing.

2.Drawing the contours of the midship frame

3. Design loads on the hull from the sea and under load

3.1 Static loads.

3.2 Wave loads.

4. General strength standard

4.1. Moment of resistance of the ship's hull

4.2. Cross-sectional moment of inertia

5. Set of the ship's hull according to the Rules

5.1 Design of the outer hull cladding.

5.1.1 Design of the outer bottom plating.

5.1.2 Design of the outer skin of the side.

5.1.3 Design of the upper deck deck

5.1.4 Design of the lining of the inclined wall of the below-deck tank.

5.1.5 Design of the lining of the inclined wall of a zygomatic tank

5.2 Design of bottom beams, second bottom and second bottom flooring.

5.2.1 Design of the second bottom flooring.

5.2.2 Set of bottom slab.

5.2.2.1 Design of continuous floras.

5.2.2.2 Design of a vertical keel.

5.2.2.3 Design of the bottom stringer.

5.2.2.4 Design of bottom longitudinal beams.

5.2.3 Design of longitudinal beams of the second bottom

5.3 Design of on-board kit.

5.4 Design of zygomatic tank structures

5.5 Design of below-deck tank structures

5.5.1 Design of the inclined wall of a below-deck tank

5.5.2 Design of longitudinal beams of VP in an under-deck tank.

5.5.3 Design of frame beams.

5.5.4 Design of the frame beam of the inclined wall of the tank.

5.6 Design of coaming-carlings.

6. Checking the overall longitudinal strength

7. List of references

Course project Structural midship frame of a bulk carrier Introduction

Calculation of the main dimensions of the vessel.

Vessel displacement Δ, t
Deadweight, t
Vessel length, m
Vessel width, m
Side height, m
Draft, m

Control:

The vessel complies with the requirements of the Rules.

Dry-cargo bulk vessel with a stern MKO arrangement and a living superstructure, forecastle, poop, inclined stem with a bulbous bow, transom stern. The vessel is single-deck with cargo hatches, double bottom, single side with side under-deck and bilge tanks.. Divided into watertight compartments by transverse bulkheads in accordance with the requirements of the Rules. A vessel with excess freeboard. Bulk cargo transported: grain, ore, sand, building materials.

1. Selecting a slab set system, grade and category of steel, spacing.

The part of the deck flooring located between the transverse coamings of adjacent cargo hatches is reinforced with transverse stiffeners, which are additionally installed on each frame between the longitudinal deck beams. The double bottom of a bulk carrier in the area of the cargo compartments is carried out using a longitudinal system of framing. The single side between the below-deck and bilge tanks is made with a transverse framing system. Side bilge tanks are made using a transverse mounting system, side below-deck tanks are made using a longitudinal mounting system.

L=189.3 m steel grade is accepted 10ХСНД s R eH=390 MPa and coefficient of utilization of mechanical properties η =0,68;

The standard yield strength is 345.6 MPa.

The normal spacing in the middle part of the vessel is determined by the formula m,

a 0 = 0.002*189.3+0.48=0.8586 where L is the length of the vessel between perpendiculars, m.

We accept a = 0.85 m .

The rules allow deviations of the taken spacing from normal within ± 25%. The calculated spacing value must be rounded: take it equal to the standard spacing value according to OST 5.1099-78. A range of standard spacing: 600, 700, 750, 800, 850, 900, 950, 1000 mm. The rules recommend not using spacing of more than 1000 mm, and using spacing of 600 mm in the forepeak and afterpeak. In addition, in the first compartment behind the forepeak bulkhead, for a distance of 0.2 L aft from the bow perpendicular, the spacing should be 700 mm. On bulk carriers, taking into account the characteristics of the cargo, solid floors should be located two spacings from the forepeak to the afterpeak bulkhead, therefore The length of the compartments is taken as a multiple of the spacing and two spacings.

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Course project

Structural midship frame of a dry cargo ship

Introduction

Calculation of the main dimensions of the vessel

Control

The vessel complies with the requirements of the Rules.

A dry cargo vessel with a stern arrangement of the MKO and a living superstructure, a forecastle, a poop, an inclined stem without a bulb, and a transom stern. The vessel is double-deck with cargo hatches, double bottom, single side. Divided into watertight compartments by transverse bulkheads in accordance with the requirements of the Rules. A vessel with excess freeboard. Cargo transported in pieces: containers, boxes, cargo on pallets (pallets).

1. Choosing a slab set system,grades and categories of steel, embossing

Because L>100h120 m - bottom and upper deck - longitudinal mounting system;

The side and lower deck - according to the transverse system of framing;

L=141 m steel grade is accepted 09G2S with R eH=315 MPa and coefficient of utilization of mechanical properties h=0,78;

Standard yield strength

2. Drawing the contours of the midship frame

Second bottom height

Normal spacing:

We take 0.75 m.

The radius of the cheekbone is equal to the height of the double bottom = 1.12 m.

Lengths of afterpeak, forepeak and MO:

mm; mm; mm.

Bilge length:

Length of the first bow hold:

Length of remaining cargo part:

dividing by the length of one spacing 750 mm we get 125 spacing. Those. the remaining cargo part will have 5 holds of 25 spaces each.

Overall length check:

Height of hold and tween deck.

We accept N TR=5200 mm; N TWIN=4480 mm.

3. Design loads on the hull from the sea and under the gratzom

Design loads on the ship's hull from the sea side are indicated by static Pst and dynamic Pw water pressure.

Static loads

Static loads acting on the ship's hull from the sea are determined by the formula:

where is the distance from the water line to the design point;

For the bottom kPa;

For the second bottom kPa;

For lower deck kPa;

For KVL and VP kPa.

Wave loads.

For force application points located below the overhead line:

where is the wave pressure at the overhead line level; ;

Parameter taking into account the speed of the vessel = 16 knots.

where for transverse cuts into the nose from amidships;

Distance of the cross section under consideration from the nearest perpendicular, m.

The result of the multiplication will be no less than 0.6.

For the bottom:

For the 2nd year bottom:

For lower deck:

For KVL:

Pressure above pressure level:

For the bottom kPa;

For the 2nd year kPa;

For lower deck kPa;

For KVL kPa;

For VP kPa.

Loada, caused by the cargo being transported

The design pressure on the second bottom from the containers is determined by the formula:

where is the estimated weight of the cargo, take 1 t/m3;

Gravity acceleration, 9.81 m/s 2 ;

The height of the cargo is 5.20 m for the second bottom, 4.48 m for the lower deck;

Estimated acceleration in the vertical direction, m/s 2:

where are the acceleration components from vertical, pitching and roll motions:

where is the pitching period

trim angle

distance from the vessel's center of gravity to the calculated point m.

where is the rolling period

Where With = 0.8; IN- vessel width equal to 19.1 m; h- initial metacentric height equal to m.

roll angle rad;

distance from the DP to the side m;

midship frame cargo ship

4. General strength standard

Determination of the necessary characteristics: moment of inertia, moment of resistance of the ship’s hull.

MomentwithPresistance to the ship's hull

where is the coefficient of utilization of mechanical properties, equal to 0.78 for steel grade 09G2S;

Total bending moment

Design bending moment:

Wave bending moment causing bending of the ship's hull:

Wave bending moment causing the vessel to sag:

where is the wave coefficient, and is the coefficient of overall completeness.

We take its maximum value as the total bending moment.

The moment of resistance of the cross-section of the hull in the middle part of the vessel must be no less than:

For the moment of resistance of the body we take its larger value 3. 8 m 3.

Moment of inertia of the cross section of the body in the middle part must be at least:

Obtained values W And I are used for comparison with the geometric characteristics of an equivalent beam, which are calculated for the midsection of the ship's hull.

5. Set of the ship's hull according to the Rules

The width of the horizontal keel is no more than 2000 mm. Its thickness should be 2 mm greater than the thickness of the outer lining of the bottom. The width of the zygomatic girdle is determined by the position of the upper and lower edges. The lower edge corresponds to the point of connection between the flat part of the bottom skin and the curved one. The upper edge in the calculations must be at least 200 mm higher than the second bottom. The thickness of the zygomatic sheet is selected from the largest of the adjacent belts.

Designer lining of the outer casing

Exterior designno bottom trim

Design diagram of the outer bottom skin plate:

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Thickness of the outer bottom skin relative to strength conditions:

Where m

a- spacing, equal to 0.75 m;

We take it equal to 1;

Thus,

10.47 mm, accept 1 1 mm.

Thickness of the outer bottom plating based on stability conditions:

Compressive stresses in the bottom due to general longitudinal bending

D- side height, 10.8 m;

We take m 4.

Critical stresses of 183.7 MPa are determined from the stability conditions of the outer skin plates, while k

13.97 mm, accept 1 4 mm,

Where b

mm, we take 2 mm, since mm.

· Thickness of the outer plating of the bottom relative to the conditions of minimum construction thickness:

Direct check of the stability of the assigned thickness of the bottom plating. To ensure stability, we take the thickness of the outer skin S=1 6 mm;

stability is ensured.

· Selecting the thickness of the horizontal keel:

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Design of the outer skin of the side.

Design diagram of the outer side skin plate:

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· Thickness of the outer skin of the side relative to strength conditions:

Where m- bending moment coefficient is 15.8;

a- spacing, equal to 0.75 m;

1.13, we take it equal to 1;

For a transverse system, the side set is 0.6;

Allowance for wear and corrosion, mm;

T- the average service life of the vessel is 24 years;

U- side corrosion rate is 0.17 mm/year;

Thus,

we accept 10 mm.

· Thickness of the outer skin of the side based on stability conditions:

k=1.0 - stability safety factor for plates.

Compressive stresses in the side due to general longitudinal bending

Distance of the neutral axis from the OP m;

The critical stress of 138.7 MPa is determined from the stability conditions of the outer skin plates.

The thickness of the outer skin plate, which meets the resistance conditions:

Where b=H TR=5.2 m - the side of the plate that receives normal compressive stresses (distance from the 2nd bottom to the lower deck);

n- coefficient taking into account the set-up system and the distribution of compressive loads along the height of the plate:

1.1 for a plate that is supported by beams of a strip-bulb profile;

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To find it, it is necessary to find the compressive stress in the lower deck using the ratio of the triangles and take it as the ratio of the smaller stresses to the larger ones (for bottom 2 and the lower deck).

138.7 MPa, because

for a single side in a dry hold.

17.5 mm, accept 18 mm to ensure stability.

· Thickness of the outer skin of the side relative to the conditions of minimum construction thickness:

The minimum building thickness must be no less than:

Selecting the thickness of the outer skin of the side S BOR=1 8 mm;

We accept the thickness of the zygomatic sheet S SCHOOL=S DN=1 8 mm.

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Upper deck deck design.

Design diagram of the upper deck plate:

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· Thickness of the upper deck deck relative to strength conditions:

Where m- bending moment coefficient is 15.8;

a- spacing, equal to 0.75 m;

We take it equal to 1;

For a longitudinal system, the set is 0.6;

Standard yield strength, 301 MPa;

Allowance for wear and corrosion, mm;

T- the average service life of the vessel is 24 years;

U- the corrosion rate of the side is 0.1 mm/year;

Thus,

4.69 mm, take 5 mm.

· Thickness of the upper deck flooring based on stability conditions:

Compressive stresses in the deck due to general longitudinal bending during deflection

Moment of inertia of the transverse section of the body

Moment of resistance of the deck in the middle part of the ship, 3.8 m 3;

D- side height, 10.8 m;

Distance of the neutral axis from the OP

Critical stresses of 201.4 MPa are determined from the stability conditions of the upper deck flooring plates, while k=1.0 - stability safety factor for plates.

Since, the calculation formula for Euler stresses will have the form:

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The thickness of the outer skin plate, which meets the resistance conditions:

12.87 mm, accept 1 4 mm,

Where b- the side of the plate receiving normal compressive stresses is 0.75 m;

n- the coefficient taking into account the mounting system and the distribution of compressive loads along the height of the plate is equal to 4;

for the upper deck.

· Thickness of the upper deck deck relative to the minimum construction thickness conditions:

The minimum building thickness must be no less than:

· Direct check of the stability of the assigned deck thickness:

We accept the thickness of the flooring mm and.

201.4 MPa, at 201.4 MPa.

With the ratio, the calculation formula for critical stresses will be:

The condition is met.

Lower deck deck design.

The lower deck is checked only by the minimum construction thickness:

We accept S NP=8 mm for deliberately ensuring strength.

Design of bottom beams, W orgo bottom and second bottom flooring

AboutDesign of the second bottom flooring

Design diagram of the second bottom plating plate:

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· Thickness of the second bottom flooring relative to strength conditions:

Where m- bending moment coefficient is 15.8;

a- spacing, equal to 0.75 m;

We take it equal to 1;

Highest design pressure, kPa;

The coefficient of the longitudinal recruitment system is 0.8;

Standard yield strength, 301 MPa;

Allowance for wear and corrosion, mm;

T- the average service life of the vessel is 24 years;

U- side corrosion rate is 0.15 mm/year;

o R 1 the calculated pressure from a single load to the second bottom (clause 3.4) is equal to 62.1 kPa;

o test pressure

o emergency flood pressure

o design pressure on the second bottom structure, if the double-bottom space is filled with ballast (- height of the air tube):

We select kPa for further calculations.

9.89 mm, accept 10 mm.

· The second bottom is not checked for stability

· Thickness of the second bottom flooring relative to the minimum construction thickness conditions:

Rounding up S VD=10 mm to obviously ensure stability, but since there will be no wooden flooring in the hold, we will increase the thickness of the flooring under the cargo hatches by 2 mm and finally accept S VD=1 2 mm.

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Bottom cover kit

The double bottom kit is located between the second bottom decking and the outer skin.

The supporting contour of the bottom floor is two sides and two adjacent transverse bulkheads.

The main set consists of longitudinal beams of the bottom and second bottom, located on each groove. Solid floras are arranged in 3 spaces. Watertight floras are located under the transverse bulkheads.

There is a vertical keel in the center plane. The distance between the vertical keel and the bottom stringer is 4.5 meters.

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Aboutectedno continuous floras

The continuous flor in the center plane has the same height as the vertical keel h=1.12 m.

· Thickness of solid floor relative to strength conditions:

Where ;

a- spacing, equal to 0.75 m;

0.78 coefficient of use of the mechanical characteristics of the material;

Allowance for wear and corrosion, mm;

T- the average service life of the vessel is 24 years;

We accept 10 mm.

· Thickness of the solid floor relative to the minimum construction thickness:

The sheet of solid flooring is reinforced by vertical stiffeners, which are located in the plane of the longitudinal beams of the bottom and second bottom.

The thickness of the stiffener is defined as:

Width of stiffener

We accept RJ continuous flora 8 H 80 mm.

Aboutequotation invertical keel

· Thickness of the vertical keel from the strength condition:

Where ; we accept ;

h F- the actual height of the vertical keel is 1.12 m;

0.78, coefficient of utilization of the mechanical characteristics of the material;

Allowance for wear and corrosion, mm;

T- the average service life of the vessel is 24 years;

U- side corrosion rate is 0.2 mm/year;

13.52 mm, accept 14 mm.

· VK thickness based on impermeability conditions:

Where m- bending moment coefficient is 15.8;

a = h f/2 - the smaller side of the VK panel is 0.56 m;

b- the larger side of the VK panel is 0.75 m

The permissible stress factor is 0.6;

Standard yield strength, 301 MPa;

Allowance for wear and corrosion, mm;

T- the average service life of the vessel is 24 years;

U- side corrosion rate is 0.2 mm/year;

Maximum design pressure, kPa;

Let's find the highest calculated pressure.

Air tube height, 1.5 m;

Distance from the middle height of the vertical keel panel to the upper deck in DP, m;

Valve pressure, 15 kPa;

We choose 124.5 kPa for further calculations.

The thickness of the vertical keel should be 1 mm greater than the thickness of the solid floor, but not less than:

The accepted thickness of the vertical keel 14 mm.

In the middle of the height of the vertical keel, to ensure the stability of the wall, we place a stiffener, which we take with the P20a profile.

Aboutechecking the bottom stringer

The thickness of the bottom stringer must be no less than the thickness of the solid floor. We accept S DS=12 mm.

AbouteCTlining the longitudinal beams of the bottom

· Moment of resistance of the longitudinal beams of the bottom relative to the strength condition:

Where m

a- spacing, equal to 0.75 m;

Standard yield strength, 301 MPa;

R- design pressure for bottom beams, 91.4 kPa;

l- beam span, 2.25 m;

Correction for wear and corrosion 1.26;

Based on the moment of resistance from Table 1, we accept R18b (h walls=180 mm; S=11 mm; b bulb = 44 mm; f=25.8 cm 2; W=218 cm 3).

· Checking a worn bulb strip at half its service life:

183.7 MPa - compressive stresses in the bottom due to general longitudinal bending;

Where i

f- cross-sectional area of the worn beam, cm 2;

l- beam run, 2.25 m;

Where h- height of the wall of the worn beam, cm;

F- wall area of the worn beam, cm 2;

F 1 - area of the free flange of the worn beam, cm 2;

F 2 - area of the attached flange of the worn beam, cm 2.

To determine the moment of inertia of a worn strip bulb, we replace it with a brand:

Where f- cross-sectional area of the bulb without attached girdle, 25.8 cm2;

h- profile height, 18 cm;

S C- thickness of the wall of the stripe bulb, 1.1 cm;

b- bulb width, 4.4 cm;

Thus, the thickness of the free belt is 1.82 cm;

The height of the tee wall will be:

cm, accept cm;

Worn cross-sectional area

Settlement brand

	b PP	S PP	h ST	S ST	b JV	S JV

f, cm 2
f", cm 2

h= 16.2 cm; F= 14.6 cm 2; F 1 =8.4 cm 2; F 2 =105 cm 2.

Aboutectedno longitudinal beams of the second bottom

· Moment of resistance of the longitudinal beams of the second bottom relative to strength conditions:

Where m- bending moment coefficient is 12;

a- spacing, equal to 0.75 m;

The permissible stress factor is 0.6 for bottom beams;

Standard yield strength, 301 MPa;

R- the highest calculated pressure on the second bottom, 112.3 kPa;

l- beam run, 2.25 m;

Correction for wear and corrosion

· Minimum construction beam wall thickness:

By moment of resistance Р20а (h walls=200 mm; S=10 mm; b bulb = 44 mm; f=27.4 cm 2; W=268 cm 3).

On-board kit design

In the area of the cargo compartment, the outer skin of the side is reinforced by the beams of the main set - frames. There are no frame frames and side stringers in both the hold and tween-deck spaces.

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Etcdesign of bilge frames

· Moment of resistance of the bilge frame from strength conditions:

Where m- bending moment coefficient is 18;

a- spacing, equal to 0.75 m;

Standard yield strength, 301 MPa;

3.58 m - distance from the water line to the design point;

l- height of the bilge part, 5.2 m;

Correction for wear and corrosion;

2 468 (h walls=240 mm; S=8.5 mm; b bulb = 71 mm; f=33.17 cm 2 ; W=442 cm 3).

No verification required.

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Pressure at the level of the mid-span of the bilge frame:

Pressure at the level of the middle span of the tween-deck frame (the middle of the span of the tween-deck frame is 1.26 m above the draft level, so there will be no static water pressure on the frame):

Projecttuning of twin-deck frames

Moment of resistance of the bilge frame from strength conditions

Where m

The permissible stress factor is 0.65;

Standard yield strength, 301 MPa;

R- design pressure in the middle of the beam span, 31.5 kPa;

l- tweendeck height, 4.48 m;

Correction for wear and corrosion;

From Table 1 we select an asymmetrical profile R2 0a (h walls=200 mm; S=10 mm; b bulb = 44 mm; f=27.4 cm 2; W=268 cm 3).

Design of zygomatic brackets

· The size of the leg of the knuckles is determined by the formula:

Where W- Design moment of resistance of the reinforced beam, 425 cm 3;

S- thickness of the reinforced beam, 8.5 mm.

S=8.5 mm, if the length of the free edge of the bracket is more than cm, then the free edge must have a flange or a belt

All books 200<C<400 должны иметь фланец b=50 mm.

We accept the book: .

Deck slab set

Main floor beams - longitudinal under-deck beams are supported on frame beams and on transverse bulkheads

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Frame beams have supports on coamings and sides. The coaming-carlings rest on frame beams.

Designedno longitudinal underdeck beams

· Moment of resistance of longitudinal under-deck beams relative to strength conditions:

Where m- bending moment coefficient is 12;

a- spacing, equal to 0.75 m;

The permissible stress factor is 0.45;

Standard yield strength, 301 MPa;

R- design pressure in the middle of the beam span, kPa;

l= 2.25 m;

36.6 cm 3< 200 см 3 ;

Correction for wear and corrosion;

From Table 1 we select an asymmetrical profile P12 (h walls=120 mm; S=6.5 mm; b bulb = 30 mm; f=11.2 cm 2 ; W=68 cm 3).

Stability check:

; stability safety factor.

201.4 MPa - compressive stresses in the upper deck (5.1.3);

Where i- moment of inertia of the cross section of the worn beam;

f- cross-sectional area of the worn beam with the attached belt, cm 2;

l- beam span, 2.25 m;

Wear for the upper deck of the dry compartment for stability is 0, so we take the moment of inertia P12 from Table 1: i=767 cm 4.

MPa - stability is ensured.

Pdesign of frame half-beams

· Moment of resistance of the frame half-beam from the strength conditions:

Where m- bending moment coefficient equal to 10;

a- 2.25 m;

The permissible stress factor is 0.65;

Standard yield strength, 301 MPa;

l- beam span, 5.05 m;

From Table 5 we accept T25a (; f prof=29.4 cm 2; I=13000 cm 4 ; f P O I'm with=100 cm 2 ; W=470 cm 3).

Where h- the height of the beam wall is 25 cm;

- allowance for wear and corrosion, 0.14 cm;

The width of the free girdle of the beam is 12 cm;

Width of attached belt, cm;

The height of the frame half-beam should be 2 times the height of the longitudinal under-deck beam.

From Table 5 we accept T28 A (; f prof=34 cm 2; I=13600 cm 4 ; f P O I'm with=100 cm 2 ; W=560 cm 3).

· Moment of inertia of the frame half-beam:

Where l- the run of the frame beam between the supports is 4.5 m;

With- distance between frame beams, 2.25 m;

Distance between longitudinal deck beams, 0.75 m;

The actual moment of inertia of the longitudinal below-deck beam with an attached belt, 767 cm 4 (for R12 );

That's why:

Actual moment of inertia of the beam I=13000 cm 4 > the required cm 4, which means rigidity is ensured.

· Wall area of the frame half-beam:

where 89.1 kN;

Wall height of the frame beam, 28 cm;

- allowance for wear and corrosion, 1.44 cm;

Allowance for wear and corrosion, mm;

T- the average service life of the vessel is 24 years;

U- side corrosion rate is 0.12 mm/year;

cm 2 - wall area is provided.

Design of beam brackets for the upper deck.

The thickness of the bracket is equal to the wall thickness of the smaller beam S=11 mm, and the legs are equal to the height of the smaller beam WITH=220 mm (P22a - twin-deck frame).

We accept book 11Х220Х220.

Design of the upper deck coaming-carlings.

Where m- bending moment coefficient equal to 10;

The permissible stress factor is 0.35;

Standard yield strength, 301 MPa;

R- design pressure at the VP, kPa;

cm 3 > 23355 cm 3.

The determination of the actual moment of resistance of the longitudinal coaming carlings is determined by calculating the geometric characteristics of this frame connection:

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Dimensions, mm	F, cm 2	FZ, cm 3	FZ 2 , cm 4	I, cm 4

Distance of the neutral axis from the reference axis:

Main central moment of inertia of the cross section:

3395095 cm 4;

Minimum moment of resistance of coaming carlings:

cm 3, which means strength is ensured.

Design of lower deck half beams.

· Moment of resistance of the lower deck half-beams relative to strength conditions:

Where m- bending moment coefficient equal to 10;

a- spacing, equal to 0.75 m;

The permissible stress factor is 0.65;

Standard yield strength, 301 MPa;

l- distance from the coaming-carlings to the side, 5.05 m;

523 cm 3 > 200 cm 3;

Correction for wear and corrosion;

Based on the moment of resistance from Table 2, we select a symmetrical profile 2 7812 (h walls=270 mm; S=12 mm; b bulb = 82 mm; f=48.33 cm 2 ; W=660 cm 3).

Designedlower deck beam brackets

· The size of the leg of the knuckle is determined by the formula:

Where W- Design moment of resistance of the bilge frame, 425 cm 3;

S- thickness of the reinforced beam, 10.5 mm.

· the thickness of the bracket must be equal to the thickness of the reinforced beam S=10.5 mm, if the length of the free edge of the bracket is more than cm, then the free edge must have a flange or a belt cm.

All books 200<C<400 должны иметь фланец b=50 mm.

We accept the book: .

DesignCarlings-coaming of the lower deck

· Moment of resistance of the lower deck Carling coaming relative to strength conditions:

Where m- bending moment coefficient equal to 10;

a- deck width, supported by coaming-carlins, 7.025 m;

The permissible stress factor is 0.65;

Standard yield strength for steel 10ХСНД, 346 MPa;

R- design pressure on the lower deck from the cargo, 53.5 kPa;

l- span of the carlings between the pillars, 14.25 m;

cm 3 > 34662 cm 3.

· Optimal height of the Carling coaming wall:

Where W- The moment of resistance of the Carling coaming is equal to 34662 cm 3;

S=S st.kk, 30 mm;

We accept h=1200 mm.

; , cm 2; TO=4.5;

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237.5 cm 2 - area of the attached belt to the cargo hatch of the NP (we assume the thickness of the NP is 20 mm);

Kominsk-Carlins shelf area: 225 cm2.

cm; Accepted Floor = 65 cm.

The actual area of the free belt is cm 2.

I accept Comins-Carlings.

cm 3 - strength is ensured.

Project formation of pillars and bulwarks

AboutDesign of twin deck peelers

Pillers ensure the transfer of forces from the deck structures to the hull structures located below. Most often they are made from metal pipes, but pillars can also be made from channels, I-sections, and box-shaped.

In the design of the deck set, the pillars are located at the intersection of the carlings and the frame beam, on the second bottom at the intersection of the solid floor and the bottom stringer.

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Where l m- length of the deck supported by the pillars, along the carlings between the middles of their purlins, 8.25 m;

b m- deck width supported by pillars, 7.025 m;

P VP- design pressure on the upper deck from the cargo, 22.4 kPa;

From Table 6.7 I take pillars 12Ch377 (6 m long, P = 1367 kN).

Design of bilge peelers

Where P NP- design pressure on the lower deck from the cargo, 53.5 kPa;

Since the resulting load is greater than the tabulated one, it is necessary to determine the cross-sectional area of the pillar ( TO=2 safety factor):

We estimate 292 cm 2 ;

We accept mm.

46.5 cm; We accept 52 cm.

l- pillar span, 6 m;

The actual area of the piller cm2 is greater than the required cm2.

We take pills 20CH520.

Designonlaying sheets

I accept backing sheet 16Х640.

Bulwark design

On dry cargo ships, the bulwarks do not take part in the overall longitudinal bending of the ship's hull. The height of the bulwarks must be at least 1 m from the upper deck.

The bulwark sheathing in the middle part of the vessel is not welded to the shearstrake, but is secured with risers, which must be located at a distance l?1.8 m one from one. The connection between the riser and the sheathing must be at least half the height of the bulwark.

I take the distance between the posts to be 1.5 m (2a).

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Bulwark sheathing thickness:

mm, I accept mm;

· thickness of the bulwark post:

Along the free edge of the rack there should be a bent flange, the width of which is:

6. Checking the overall longitudinal strength

After determining the dimensions of the connections of the structural midship frame of a dry cargo ship, a design diagram of the equivalent beam is drawn, which includes all the longitudinal connections of the hull, which take part in the overall longitudinal bending. The obtained geometric characteristics are compared with the minimum ones, previously calculated in point 4.

Calculation of equivalent timber

Name and size of connection	Connection size, mm	Connection area Fi, cm 2	Ordinate from the comparison axis Zi, m	Stat moment of inertia Fi×Zi, cm 2 Chm	Moment of inertia
					Portable FiçZi 2, cm 2 Chm 2	Own I, cm 2 Chm 2
Horizontal keel
Bottom lining
Zygomatic sheets

Bottom stringer



Outer sheet of VD
Middle sheet VD
HP flooring under the hatch cutout
VD flooring

Shearstreck
NP flooring

Shelf KK NP
Pal stringer
VP flooring

Wall KK VP
Regiment KK VP
					207352.7
					C=214229.3

ABOUT distance of the neutral axis from the comparison axis.

Where A- sum of static moments of bond areas, cm 2 m;

IN- sum of cross-sectional areas of bonds, cm 2.

Principal central moment of inertia of the cross section of the court on a relatively neutral axis

Where WITH- the sum of the portable and natural moments of inertia of the cross sections of the links, cm 2 m 2;

Moments of resistance changes in the cross sections of the body

· Moment of resistance of the VP cross section:

Where D- height of the vessel, 10.8 m;

m 3 - since the condition is not met - it is necessary to increase.

· Moment of resistance of the bottom cross section:

Since, we increase some of the connections of the upper flange of the equivalent beam.

m 4 - the rigidity of the body is ensured!

m 3 - the strength of the VP is ensured!

m 3 - the strength of the bottom is ensured!

Conclusion: Overall longitudinal strength is guaranteed!

List of used literature

1. Design of the structural midship frame of dry-hull vessels: Methodical introduction / V.G. Matveev, A.I. Kuznetsov, B.M. Martinets, B.M. Mikhailov, O.M. Uzlov, M.O. Tsibenko, G.V. Sharun. - Nikolaev: UDMTU, 2002. - 76 p.

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Course project structural midship frame of a bulk carrier introduction. Structural midsection frame of a dry cargo ship Structural midsection frame of a dry cargo ship

Midship frame of a bulk carrier using a transverse frame system

Midship frame of a bulk carrier using a mixed system of framing

Key Dimensions

Main dimensions

What is a theoretical drawing?

What are completeness factors?

Course project Structural midship frame of a bulk carrier Introduction

1. Selecting a slab set system, grade and category of steel, spacing.

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