project 5 - notes
TRANSCRIPT
Universiti Teknologi MalaysiaUniversiti Teknologi Malaysia
Faculty of Mechanical EngineeringDepartment of Marine Technology
STRUCTURAL DESIGNAND STRENGTH ASSESSMENT
Prepared By
HJ. YAHYA BIN [email protected]
Department of Marine TechnologyFaculty of Mechanical Engineering
Universiti Teknologi Malaysia81310, UTM SkudaiJohor Bahru, JOHOR
July 2005
Structural Design and Strength Assessment Note - 1/16
SHIP STRUCTURES DESIGN
Department of Marine Technology, FKM, UTM, 2005
3.0 Introduction
Structural design is an important design task andone of the most difficult parts in ship design thatoften required deep understanding and vastexperience. It requires good knowledge on shipstructures and often involves a lot and tediouscalculation, initial estimation (guestimate) with littleinformation, judgement and critical decision making.Whilst strength is the most important aspect instructural design which is not to be compromised atany time, it is also important to consider the weightand function of the ship so that the ship can beoperated in cost effective manner. Therefore it isessential that the designer have a good exposure andhad gone through structural design exercise beforeembarking on serious design project.
4.0 Aim of the Note
This note is written to facilitate the participants witha brief guideline on how ship structures should bedesigned based on the Lloyds Register Rules andRegulations. The details can be referred to the rulesand the participant will be given a copy of theselected part of the rule during the hands on project.
1.0 Structural Design Process
The ship structure is design upon completion of linesplan and general arrangement design as indicated inFigure 1. Structural design is also an essential part ofproduction process as it provides important data formaterial ordering and costing. In general practice, themidship scantling of the ship is to be designed firstand the rests / detailing of the structures will bederived from it. Midship scantling is also important todetermine the overall strength of the ship, whichneed to be known at the early of design stage. Thedesign process may differ from one rule to another,but generally it involves determination of ruledimensions, material selection, framing systems,determination of plating thickness and stiffener /frames sizes, midship scantling drawing and strengthassessment.
2.0 Midship Scantling CalculationProcedures Using Lloyds Rules
The ship structures can be designed with threedifferent approach; From first principles (rationaldesign), using rules and regulation / standards, ormixed of both above. Design from first principles istedious and involves a large amount of man- hours. It
Structural Design and Strength Assessment Note - 2/16
often done for novel or military vessels. For Merchantships, the structural design is normally designedbased on rules and regulation developed byclassification societies. The conventional rules useformula that were based purely on empirical data ofprevious good designs and often are overly designed.The new approach, however, as in Lloyds Register,had incorporated first principles calculation in theformula especially in the strength assessment. Thiswill allow the designer to rationalize his/her design inorder to be more cost effective.
The midship scantling calculation procedures usingLloyds Register Rules is shown in Figure 2. Itbasically involves determination of rule dimensionsmeasured from lines plan drawing, selection ofmaterial properties, equipment number and designloading appropriate to the required location. Oncethese basic data have been determined (sameprocedure for all types of ships), the followingcalculation will be based on the specific type of shipbeing designed. As an example in Figure 2, thegeneral cargo is selected and the scantling designinvolves calculation of plating thickness for deck,shell envelope, scantling for deck and shell envelopestiffening members, bottom structures andbulkheads thickness and stiffeners sizes. Uponcompletion of midship scantling calculation, strength
assessment need to be carried out. In order to do thisaccurately, first the midship scantling need to bedrawn / sketched in scaled and all measurementmust be taken from this drawing. Then the overallsection modulus of the ship structures or hull girdercan be calculated using the standard procedures. TheHull bending strength and shear strength will bedetermined based on the hull girder section modulus.For local strength, the plate panel strengthassessment will be done using hull buckling strengthcriteria. The strength assessment procedure is shownin Figure 4.
Although the scantling formula used in Lloyds rulesmay differ form other rules, the basic concept andcalculation procedures in general, remain the same.Therefore it is expected that once the designer hasexperienced in one particular rule, he/she will beable to design in other rules without any difficulty.
5.0 Hands on Structural Design Project
The participants will be given a hands on structuraldesign task of a selected general cargo. The step bystep design procedure is given in Table 1. All thenecessary formula, calculation sheets, drawings anddiagrams will also be given during the hands onstructural design project.
Department of Marine Technology, FKM, UTM, 2005
SHIP STRUCTURES DESIGN
Structural Design and Strength Assessment Note - 3/16
FIGURE 1: Structural Design Process
DESIGNREQUIREMENTS
MAINDIMENSIONS
HULL FORMDESIGN
HYDROSTATICSCALCULATION
GENERALARRANGEMENT
PRELIMINARYWEIGHT ESTIMATION
Preliminary Design
RULE DIMENSION
MATERIAL PROPERTIES
LOADING CALCULATION
PLATING THICKNESS
STIFENERS SCANTLING
SELECTION OF FRAMING SYSTEM
OTHER STRUCTURES SCANTLING
STRUCTURES SCANTLING LIST
MIDSHIP SCANTLINGDRAWING
STRENGTH ASSESSMENT
Strutural Design Process
NESTING
MATERIALTAKE OFF
SHELLEXPANSION
STRUCTURALDETAILING
MATERIALCOST
Production Design
Department of Marine Technology, FKM, UTM, 2005
Structural Design and Strength Assessment Note - 4/16
FIGURE 2 : Midship Scantling Calculation Procedures – Lloyds Rules
Department of Marine Technology, FKM, UTM, 2005
RULE DIMENSIONS(Part 3, Chapter 1, Section 6.1- 6.8)
EQUIPMENT NUMBER(Part 3, Chapter 1, Section 7.1)
ALL SHIPS
MATERIAL PROPERTIES(Part 3, Chapter 2, Section 1.1- 2.1)
STRUCTURAL IDEALIZATION(Part 3, Chapter 3, Section 3.1- 3.3)
BULKHEAD REQUIREMENTS(Part 3, Chapter 3, Section 4.1- 4.4)
DESIGN LOADING(Part 3, Chapter 3, Section 5.1- 5.3)
GENERAL CARGO
SYMBOLS & DEFINITIONS(Part 4, Chapter 1, Section 1.5)
DECK PLATING(Part 4, Chapter 1, Section 4.2)
SHELL ENVELOPE PLATING(Part 4, Chapter 1, Section 5.1 – 5.4)
SHELL STIFFENING(Part 4, Chapter 1, Section 6.1 – 6.4)
DECK STIFFENING(Part 4, Chapter 1, Section 4.3 – 4.4)
BOTTOM STRUCTURES(Part 4, Chapter 1, Section 7.1 – 8.5)
BULKHEADS(Part 4, Chapter 1, Section 9.1 – 9.2)
STRENGTH
HULL BENDING STRENGTH(Part 3, Chapter 4, Section 5.1 –5.9
HULL SHEAR STRENGTH(Part 3, Chapter 4, Section 6.1 –6.7
HULL BUCKLING STRENGTH(Part 3, Chapter 4, Section 7.1 –7.5
MIDSHIPSCANTLING DRAWING
MIDSHIPSECTION MODULUS
Structural Design and Strength Assessment Note - 5/16
STEP TASKS
1 Preparing Data and Drawings (Lines Plan, GA, Hydrostatics, Capacity Plan etc). A sketch (scaled)on Midship Frame Section is required based on Lines Plan and GA Drawing.
2 Preparation of Calculation Sheets – see examples in Table 2(a) and 2 (b).
FOR ALL TYPES OF SHIPS
3Based on the GA and Lines Plan Drawing Determine the Rules Dimension, L, B, D, T, CB etc. Alsodetermine the weather /strength /freeboard deck as required by (Part 3, Chapter 1, Section 6.1-6.8). Also calculate the Equipment Number based on (Part 3, Chapter 1, Section 7.1).
4Select material to be used. For high Tensile steel or Aluminum, determine the Material PropertiesFactors as in (Part 3, Chapter 2, Section 1.1- 2.1). These factors will be used throughout thescantling calculation.
5If Bulkheads Number and Location need to be checked, used (Part 3, Chapter 3, Section 4.1-4.4) to determine the minimum number of bulkheads, position of collision bulkhead and aft end bkhdarrangement. Transverse bkhds location need to be adjusted to the nearest frame location.
6Loading Calculation – Based on (Part 3, Chapter 3, Section 5.1- 5.3), Determine the appropriatedesign Load, design head, stowage factors etc for decks, tanks and bkhds. The design load must becalculated based on the position (height) of the structures in consideration.
TABLE 1 : Structural Design Project – Hands On
Department. of Marine Technology, FKM, UTM, 2005
Structural Design and Strength Assessment Note - 6/16
STEP TASKS
FOR GENERAL CARGO
7 Determining the Basic Data for calculation as required in (Part 4, Chapter 1, Section 1.5).
8Selection of Framing Systems (Longitudinal or Transverse) and Frame Spacing. Stiffeners,Longitudinals, Stringers, etc spacing need also to be selected. No specific formula is given, thus itshould be determined based on shipyard standard practices.
9 Calculation of Deck Plating Thickness based on (Part 4, Chapter 1, Section 4.2).
10 Calculation of Shell Envelope Plating Thickness (Keel, Bottom & Bilge, and Side Shell)as requiredby (Part 4, Chapter 1, Section 5.1 – 5.4).
11Calculation of Deck Stiffening Section Modulus for Deck Longitudinals, Beams, and Girdersbased on (Part 4, Chapter 1, Section 4.3 – 4.4). The scantling of deck stiffening members should bedetermined based on Structural Idealization as specified in (Part 3, Chapter 3, Section 3.1- 3.3).
12
Calculation of Shell Envelope Stiffening Section Modulus for Logituidinals or Transverse, andPrimary Structures based on (Part 4, Chapter 1, Section 6.1 – 6.4). The scantling of shell envelopestiffening members should also be determined based on Structural Idealization as specified in(Part 3, Chapter 3, Section 3.1- 3.3).
Structural Design Project – Hands On
Department of Marine Technology, FKM, UTM, 2005
Structural Design and Strength Assessment Note - 7/16
STEP TASKS
13Calculation of Bottom (Single or Double Bottom) Structures Plating Thickness and Stiffeningmembers Section Modulus as required by (Part 4, Chapter 1, Section 7.1 – 8.5). The calculationincludes Girders, Floors, and Inner Bottom Plating and Longitudinals.
14 Calculation of Bulkheads Platting Thickness and Stiffeners Section Modulus for watertightdeep tank bulkheads and Shaft Tunnel based on (Part 4, Chapter 1, Section 9.1 – 9.2).
STRENGTH ASSESSEMNT
15Preparation of Scantling List, which should at least includes Name, numbers, sizes (thickness andstiffeners scantling). See example in Table 3. This list will be used for strength calculation andmaterials take off.
16Preparation of Midship Scantling Drawing / sketches based on lines plan, GA and scantling list.The scantling drawing should be drawn in scale. Clearly label the structures name and size. Seeexample Figure 3.
17Calculation of Moment of Inertia and Section Modulus of the Hull Girders. Hull girder shouldconsists of all continuous longitudinal structures as specified in (Part 3, Chapter 3, Section 3.4). UseCalculation Tables as shown in the example in Table 4 and the formula given Table 5 & 6.
Structural Design Project – Hands On
Department of Marine Technology, FKM, UTM, 2005
Structural Design and Strength Assessment Note - 8/16
18
Determine the Hull Bending Strength by Calculation of Design Vertical Wave BM, Design StillWater BM, Minimum section Modulus, Permissible Still Water BM, Permissible HullVertical Bending Stress, Factors of reduction, and Minimum Moment of Inertia as requiredby (Part 3, Chapter 4, Section 5.1 – 5.9). Strength is to be determine by comparing the requiredminimum or permissible to the actual or design value.
19
Determine the Hull Shear Strength by calculating Design Wave SF, Design Still Water SF,Design Shear Stress, Permissible Still Water SF, Permissible Shear Stress as required by(Part 3, Chapter 4, Section 6.1 – 6.7). Strength is to be determine by comparing the permissible tothe design value
20Determine the Hull Buckling Strength (Local Strength) by calculating or checking the ElasticCritical Buckling Stress, Design Stress and comparing with Scantling Criteria as given by(Part 3, Chapter 4, Section 7.1 – 7.5).
21
Based on the Strength Assessment, Modification of Structural Scantling may be required eitherto increase the strength (in case of inadequate strength) or reducing strength (in case of excessivestrength / overly design). The modification can be in the form of adding/removing structures,changing plating thickness or/and changing section modulus for stiffening members. It isrecommended that once modification has been carried out, the strength Assessment need to becarried out once again.
Structural Design Project – Hands On
Department of Marine Technology, FKM, UTM, 2005
Structural Design and Strength Assessment Note - 9/16
LLOYDS SCANTLING CALCULATION : LOADING
NO ITEM (unit) SYMBOL FORMULA INPUT CALCULATIONRESULT DESIGN REF
1 General Loading - - - - - Pt.3, Ch.3 - 5.2.1(Table 3.5.1)
2 Weather Deck (Standard Cargo)2(a) Frd. - 0.075L from FP
Design Load for Beam/Long(KN/m^2)
p 12.73
Design Load for Prime Structure(KN/m^2)
p 29.64 + 14.41E
E = (0.0914 + 0.003L)/(D-T)-0.15
Pt.3, Ch.3 - 5.2.1(Table 3.5.1)
but must 0.0 ≤ E ≤ 0.147
Equivalent Design Head -Beam/Long(m) h1 1.8
Equivalent Design Head - PrimeStructures(m) h1 4.2 + 2.04E Pt.3, Ch.3 - 5.2.1
(Table 3.5.1)
Standard Stowage (m^3/tonnes) C 1.39Permissible Cargo Loading(KN/m^2) 8.5
Equivalent Permissible Head (m) 1.2
TABLE 2(a) : Example of Scantling Calculation Sheet
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Structural Design and Strength Assessment Note - 10/16
LLOYDS SCANTLING CALCULATION : BKHD NUMBER AND COLLISION BKHD
NO ITEM (unit) SYMBOL FORMULA INPUT CALCULATIONRESULT DESIGN REF
1 No of Bulkheads See Table 3.4.1 Pt.3, Ch.3 - 4.1.1(Table 3.4.1)
2 : Ship Without Extending Part of Underwater Body more than LL (Other Than Passenger Ships)
2(a) Collsion Bulkhead Ship <= 200 mDistance From Fore End of LL(m)
Pt.3, Ch.3 - 4.2.1(Table 3.4.2)
Minimum 0.05LL LL from Pt.3,Ch.1 -6.1.8
Maximum 0.08LL
2(b) Collsion Bulkhead Ship > 200 mDistance From Fore End of LL(m)
Pt.3, Ch.3 - 4.2.1(Table 3.4.2)
Minimum 10
Maximum 0.08LLLL from Pt.3,Ch.1 -6.1.8
TABLE 2(b): Example of Scantling Calculation Sheet
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Structural Design and Strength Assessment Note - 11/16
Size ZSTRUCTUREDESCRIPTION Thickness (mm) Web (mm)
No.(m From Keel)
Bottom Plate 6 - 0Inner Bottom Plate 6 - 2.8Deck Plate 8 - 10Side Plating 7 - 6.15Centre Girder 7.5 1 1.4Side Girder 6 1 1.4Long BKHD 6 1 6.4bilge Plating 8 - 1.15Margin Plate 6 - 2.55Deck Longi L - 6x20x20 4 9.8Side Longi -1 T - 6x15x15 8.3Side Longi -2 T- 6x15x15 6.3Side Longi -3 T- 6x15x15
34.3
Inner Botton Longi Bulb - 5x20x10 5 2.5Bottom Longi Top Hat - 5x10x10 2 0Bilge Longi -1 I – 6x15x15 0.43Bilge Longi -2 I – 6x15x15
21.15
TABLE 3: Example of Scantling List
Department of Marine Technology, FKM, UTM, 2005
Structural Design and Strength Assessment Note - 12/16
4 m
SIDE GIRDERt = 6 mm
BOTTOM LONGL
A = 12 cm2
BILGE LONGL
A = 10 cm2
BOTTOM PLATEt = 10 mm
BILGE PLATEt = 10 mm
INNER BOTTOM LONGL
A = 12 cm2
INNER BOTTOM PLATEt = 6 mm
BILGE PLATEt = 6 mm
SIDE PLATEt = 7 mm
LONG BKHD PLATEt = 6 mm
DECK PLATEt = 8 mm
SIDE LONGL
A = 12 cm2
CENTREGIRDERt = 6 mm
DECK LONGL
A = 12 cm2
8 m
1.5 m 1.75 m 1.5 m 1.5 m
1.5m
2.0m
2.0m
2.0m
2.3m
1 m 2.5 m 1.25 m 1.25 m
0.5 m1 m 1 m1 m2 m
2.8 m
2.5m
FIGURE 3: Example of Midship Scantling Drawing
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Structural Design and Strength Assessment Note - 13/16
L t Z A 1st Mmt 2nd Mmt Io Angle hNO STRUCTURE
DESCRIPTION (m) (mm) (m From Keel) (m.mm) (m2.mm) (m3.mm) (m3.mm)Type
(deg) (m)1 Bottom Plate 4 6 0 24 0 0 0 HP
2 Inner Bottom Plate 5.5 6 2.8 33 92.4 258.72 0 HP
3 Deck Plate 4 8 10 32 320 3200 0 HP
Side Plating 7.7 7 6.15 53.9 331.485 2038.63275 266.311 VP
4 Centre Girder 2.8 7.5 1.4 21 29.4 41.16 13.72 VP
5 Side Girder 2.8 6 1.4 16.8 23.52 32.928 10.976 VP
6 Long BKHD 7.2 6 6.4 43.2 276.48 1769.472 186.624 VP
7 bilge Plating 4.61 8 1.15 36.88 42.41 48.77 16.33 IP 30 1.15
8 Margin Plate 2.54 6 2.55 15.24 38.84 99.01 0.31 IP 11.3 0.25
9Deck Longi x 4(4x10/10) 9.8 4 39.20 384.16 0 Sec
10Side Longi -1(1x12/10) 8.3 1.2 9.96 82.67 0 Sec
11 Side Longi -2 6.3 1.2 7.56 47.63 0 Sec
12 Side Longi -3 4.3 1.2 5.16 22.19 0 Sec
13 Inner Botton Longi x 5 2.5 4 10.00 25.00 0 Sec
14 Bottom Longi x 2 0 2.4 0.00 0.00 0 Sec
15 Bilge Longi -1 0.43 1 0.43 0.18 0 Sec
16 Bilge Longi -2 1.15 1 1.15 1.32 0 Sec
292.02 1228.00 8051.85 494.28
∑∑ A ∑∑1st Mmt ∑∑2nd. Mmt ∑∑ Io
TABLE 4: Example of Section ModulusCalculation
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Structural Design and Strength Assessment Note - 14/16
Actual Section Modulus
FORMULA ITEM VALUE UNIT VALUE UNIT
(a) ∑∑ A Total Area = 292.02 m.mm
(b) ∑∑1st Mmt Total 1st. Moment = 1228.00 m2.mm
( c) (b)/(a) Dist of NA from Keel = 4.21 m
(d) ∑∑2nd. Mmt Total 2nd. Moment = 8051.85 m3.mm 80518.49 m2.cm2
(e) ∑∑ Io Total Io = 494.28 m3.mm 4942.78 m2.cm2
(f) (d) + (e) Total I about Keel = 85461.27 m2.cm2
(g) (f) – (a)*(c)2 Total I about NA = 80297.28 m2.cm2
(h) Measure Height of Deck = 10.00 m
(i) (h) – ( c) or (c )whichever greater
Max y (ydeck or Ykeel) = 5.79 or 4.21 5.79 m
(j) (g) / (i) Section Modulus (Half) = 13856.78 m2.cm2
(k) (j) x 2 Section Modulus (Full) = 27713.5562 m2.cm2
Required Section Modulus (Lloyds Rules)
SM required = 10422.272 m2.cm2 Calculated based on emphirical Formula
SF = SM actual / SM required = 2.66 Acceptable but overly designed
TABLE 5 : Example of Section Modulus Calculation
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Structural Design and Strength Assessment Note - 15/16
TYPE 1 : Vertical PlateData Required and Calculation Diagram
L = Length (m)t = Thickness (mm)Z = Distance of Centroid from keel (m)A = Area = L x t (m.mm)1st. Moment = A x Z (m2.mm)2nd. Moment = A x Z2 or 1st Moment x Z (m3.mm)Io = Inertia Moment = L3 x t (m3.mm)
TYPE 2 : Horizontal PlateData Required and Calculation Diagram
L = Length (m)t = Thickness (mm)Z = Distance of Centroid from keel (m)A = Area = L x t (m.mm)1st. Moment = A x Z (m2.mm)2nd. Moment = A x Z2 or 1st Moment x Z(m3.mm)Io = Inertia Moment = 0 (Negligible)
TYPE 3 : Inclined PlateData Required and Calculation Diagram
L = Length (m)t = Thickness (mm)h = Distance of Centroid to base = L/2 x Sin(θθ )Z = Distance of Centroid from keel (m)A = Area = L x t (m.mm)1st. Moment = A x Z (m2.mm)2nd. Moment = A x Z2 or 1st Moment x Z(m3.mm)Io = [A x (2xh)2 ] / 12 (m3.mm)
TYPE 4 : SectionsData Required and Calculation Diagram
A = Area (m.mm) = Area (cm2/100) = Area (mm2/1000)Z = Distance of Centroid from keel (m)1st. Moment = A x Z (m2.mm)2nd. Moment = A x Z2 or 1st Moment x Z(m3.mm)Io = 0 (Negligable)Sections can be grouped together provided theyhave the same centroid position (Z)
L
t
Z From Keel
L
t
Z From Keel
L
t
Z From Keel
hθθ
Z From Keel
TABLE 6: Formula for Midship Section Modulus
Department of Marine Technology, FKM, UTM, 2005
Structural Design and Strength Assessment Note - 16/16
FIGURE 4: Strength Assessment Procedure
HULL BUCKLING STRENGTH
Scantling
MIDSHIP SCANTLINGDRAWING / SKETCHES
MIDSHIPSECTION MODULUS & INERTIA
DETERMINATION OFRULE DIMENSION
ASSUMING INITIAL DESIGNVALUES & FACTORS
CALCULATION OF PLATES ANDSTIFFENERS SCANTLING
Overall Strength
HULL BENDING STRENGTH
Calculation of;f) Design Wave Bending Momentg) Design Still Water Bending Momenth) Minimum Hull Section Modulusi) Permissible Still Water BMj) Permissible Vertical BMk) Local Scantling Reduction Factors
ComparisonBetween Design and
Permissible
CHANGING INITIAL DESIGNVALUES & FACTORS
NO
ComparisonBetween Design
and Criteria
Local Strength
Calculation of;a) Critical Buckling For Plateb) Critical Buckling For Longic) Design Stressd) Scantling Criteria
HULL SHEAR STRENGTH
Calculation of;a) Design Wave Shear Forceb) Design Still Water Shear
Forcec) Design Shear Stressd) Permissible Still Water SF
NO
STOP
YES
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YES
YES
Department of Marine Technology, FKM, UTM. 2005
STRUCTURAL SCANTLING CALCULATION SHEETS(Based on LLOYDS Rules and Regulation 1997)
Important Note
The calculation sheets used in this short course were designed for the purpose ofdemonstrating the calculation procedures and examples of selected structures andfor a specific type of ship. Under no circumstances do they represent the completecalculation process provided in the rules. All formula shown in the calculationsheets should be checked with the formula given in rules.
Calculation Sheet – Rule Dimensions - 1
STRUCTURAL DESIGN CALCULATION SHEET – RULE DIMENSIONS & EQUIPMENT NUMBER
NO ITEM (unit) SYMBOL FORMULA INPUTCALCULATION
RESULT DESIGN REF
1 Length (m) L Pt.3,Ch.1 - 6.1.1
2 Breadth (m) B Pt.3,Ch.1 - 6.1.3
3 Depth (m) D Pt.3,Ch.1 - 6.1.4
4 Draught (m) T Pt.3,Ch.1 - 6.1.5
5 Block Coef Cb Pt.3,Ch.1 - 6.1.6
6 Length Bet PP (m) Lpp Pt.3,Ch.1 - 6.1.7
7 Length Load Line (m) LL Pt.3,Ch.1 - 6.1.8
8 Block Coef at LL Cbl Pt.3,Ch.1 - 6.1.9
9 Equipment Number EqNEqN = Disp^2/3 +2BH+A/10
Displacement (Tonnes) Disp
Freeboard Height (m) H
Area in Profile View(m2) A
A = L x (H + Hss)Hss = Height ofSuperStrctures
Pt.3,Ch.1 - 7.1.1
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Calculation Sheet – Material Properties - 1
STRUCTURAL DESIGN CALCULATION SHEET – MATERIAL PROPERTIES
NO ITEM (unit) SYMBOL FORMULA INPUTCALCULATION
RESULT DESIGN REF
A : For Steel (Mild and High Tensile Steel)
1 Material Types - - Pt.3,Ch.2 - 1.1
2High Tensile SteelFactor For Hull GirderSM
KL
3 Specific Min Yield Stress SigmaO
Pt.3,Ch.2 - 1.2.2(Table 2.1.1)
4High Tensile SteelFactor For LocalStrength
Kk = 235/SigmaOor = 0.66 whiheverhigher
Pt.3,Ch.2 - 1.2.3
B : Aluminum Alloy
1 Aluminum Alloy Types - -
2 Yield Stress (N/mm^2) SigmaAPt.3,Ch.2 - 1.3(Table 2.1.2)
3 Thickness Equi Factor TeF (ka)^0.5*c
ka = 245/sigmaA
Factor c = 0.95 or 1.0
4 SM equi Factor SMeF ka*c
Pt.3,Ch.2 - 1.3.2
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Calculation Sheet – Loading - 1
STRUCTURAL DESIGN CALCULATION SHEET – LOADING
NO ITEM (unit) SYMBOL FORMULA INPUTCALCULATION
RESULT DESIGN REF
1 General LoadingPt.3, Ch.3 - 5.2.1(Table 3.5.1)
2 : Weather Deck (Standard Cargo)Aft of 0.12L from FP (KN/m^2)
Design Load for Beam/Long p 8.5+ 14.41E
Design Load for PrimeStructure p 8.5+ 14.41E
E = (0.0914 +0.003L)/(D-T)-0.15but must0.0 <= E <= 0.147
Pt.3, Ch.3 - 5.2.1(Table 3.5.1)L, D & T refer toPt.3,Ch.1 - 6.1.5
Equi Design Head -Beam/Long(m) h1 1.2 + 2.04E
Equi Design Head - PrimeStruct(m) h1 1.2 + 2.04E
Pt.3, Ch.3 - 5.2.1(Table 3.5.1)
Standard Stowage(m^3/tonnes) C 1.39
Permissible Cargo Loading(KN/m^2)
8.5
2(c)
Equivalent Permissible Head(m) 1.2
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Calculation Sheet – Loading - 2
NO ITEM (unit) SYMBOL FORMULA INPUTCALCULATION
RESULT DESIGN REF
4 : Cargo Deck
Standard Cargo LoadPt.3, Ch.3 - 5.2.1(Table 3.5.1)
Design Load for All Structures(KN/m^2) p
7.07HtdHtd (m) = CargoHead in Twee Deck
Pt.3, Ch.3 - 5.2.1(Figure 3.5.1)
Equi Design Head (m) - AllStructures h1 Htd
Standard Stowage (m^3/tonnes) C 1.39Permissible Cargo Loading(KN/m^2) 7.07Htd
4(a)
Equivalent Permissible Head (m) Htd
Mach Space, W/Syop and StoresPt.3, Ch.3 - 5.2.1(Table 3.5.1)
Design Load for All Structures(KN/m^2)
p 18.37
Equi Design Head (m) - AllStructures h1 2.6
4(c)
Standard Stowage (m^3/tonnes) C 1.39
Ship StoresPt.3, Ch.3 - 5.2.1(Table 3.5.1)
Design Load for All Structures(KN/m^2) p 14.14
Equi Design Head (m) - AllStructures h1 2
4(d)
Standard Stowage (m^3/tonnes) C 1.39
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Calculation Sheet – Loading - 3
NO ITEM (unit) SYMBOL FORMULA INPUTCALCULATION
RESULT DESIGN REF
5: Accommodation Deck
Accommodation DeckPt.3, Ch.3 - 5.2.1(Table 3.5.1)
Design Load for All Structures(KN/m^2) p 8.5
Equi Design Head (m) - AllStructures
h1h3 or 1.2 which ever
greaterPt.3, Ch.3 - 5.2.1(Figure 3.5.1)
5(a)
Standard Stowage (m^3/tonnes) C 1.39
6 : Superstructure DeckPt.3, Ch.3 - 5.2.1(Table 3.5.1)
6(a)For F'castle deck Frd of 0.12 Lfrom FP See Weather Deck (2)
6(b) Equi Design Head (m) - S/s Deck h1 h3Pt.3, Ch.3 - 5.2.1(Figure 3.5.1)
6( c)Equi Design Head (m) - 1st TierBeams & Longl h1
0.9 (+ 0.24E ifexposed)
6(d)Equi Design Head (m) - 2nd TierBeams & Longl h1
0.6 (+ 0.24E ifexposed)
6(d)Equi Design Head (m) - 3rd TierBeams & Longl h1
0.45 (+ 0.24E ifexposed)
Department of Marine Technology, FKM, UTM. 2005
Calculation Sheet – Loading - 4
NO ITEM (unit) SYMBOL FORMULA INPUTCALCULATION
RESULTDESIGN REF
8 : Inner BottomPt.3, Ch.3 - 5.2.1(Table 3.5.1)
Ship Without Heavy Cargo Notation
Design Loading (KN/m^2) - Plate& Stiffeners p
Equi Design Head (m) - - Plate &Stiffeners
h1
Standard Stowage (m^3/tonnes) C 1.39
Permissible Cargo Loading(KN/m^2) 9.82T
T refer toPt.3,Ch.1 - 6.1.5
8(a)
Equivalent Permissible Head (m) 1.39T
Watertight Bulkhead
Design Loading (KN/m^2) - Plate& Stiffeners p 10.07h4
Pt.3, Ch.3 - 5.2.1(Figure 3.5.2)
Equi Design Head (m) - - Plate &Stiffeners
h1h4 = Appropriate
Design Head
8(c)
Standard Stowage (m^3/tonnes) C 0.975
Department of Marine Technology, FKM, UTM. 2005
Calculation Sheet – Bkhd No & Collision Bkhd - 1
STRUCTURAL DESIGN CALCULATION SHEET – BKHD NO & POSITION OF COLLISON BKHD
NO ITEM (unit) SYMBOL FORMULA INPUT CALCULATIONRESULT
DESIGN REF
1 No of Bulkheads See Table 3.4.1Pt.3, Ch.3 - 4.1.1(Table 3.4.1)
2 : Ship Without Extending Part of Underwater Body more than LL (Other Than Passenger Ship)
2(a) Collision Bulkhead Ship <= 200 m
Distance From Fore Endof LL (m)
Pt.3, Ch.3 - 4.2.1(Table 3.4.2)
Minimum 0.05LL
Maximum 0.08LL
LL from Pt.3,Ch.1 -6.1.8
2(b) Collision Bulkhead Ship > 200 m
Distance From Fore Endof LL (m)
Pt.3, Ch.3 - 4.2.1(Table 3.4.2)
Minimum 10
Maximum 0.08LL
LL from Pt.3,Ch.1 -6.1.8
Department of Marine Technology, FKM, UTM. 2005
Calculation Sheet – Deck Plating - 1
STRUCTURAL DESIGN CALCULATION SHEET – DECK PLATING
ITEM (unit) SYMBOL FORMULA INPUT CALCULATIONRESULT
DESIGN REF
1 : Basic Input Data
1Higher Tensile StrengthFactor - For Hull Girder kL
Higher Tensile StrengthFactor - For LocalStrength
k
Pt.3,Ch.2 - 1.2.2(Table 2.1.1)
Spacing for SecondaryStiffeners (mm)
s
Spacing for PrimaryMembers (m) S
Wave Head (m) CW 7.71x10^-2 x Lx e^(-0.0044L)
Relative Density Rho not to lee than 1.025
Pt.4, Ch.1 - 1.5
Department of Marine Technology, FKM, UTM. 2005
Calculation Sheet – Deck Plating - 2
NO ITEM (unit) SYMBOL FORMULA INPUT CALCULATIONRESULT
DESIGN REF
2 : Strength / Weather Deck Plating (Longitudinal Framing)
2(a) Outside Line of Opening
Thickness (mm) tt = 0.001 x s1 x(0.059L1+7) xSQRT(FD/KL) OR
Pt.4, Ch.1 - 4.2.1(Table 1.4.1)
t = 0.00083 x s1 xsqrt(LK)+2.5Which ever GreaterFD = Scant ReductionFactor Pt.3, Ch.4 - 5.7.2
s1 = s but bot to lessthan 470+L/0.6 or700 whichever LowerL1 = L but<=190
2(b) Inside Line of Opening
Thickness (mm) tt = 0.00083 x s1 xsqrt(LK)+2.5
But not less than 6.5s1 = s but bot to lessthan
470+L/0.6 or
700 whichever Lower
Pt.4, Ch.1 - 4.2.1(Table 1.4.1)
Department of Marine Technology, FKM, UTM. 2005
Calculation Sheet – Shell Plating - 1
STRUCTURAL DESIGN CALCULATION SHEET – SHELL ENVELOPE PLATING
NO ITEM (unit) SYMBOL FORMULA INPUT CALCULATIONRESULT
DESIGN REF
1 : Basic Input Data and Preliminary Calculation
Basic Input Data
Higher Tensile StrengthFactor - For Hull Girder
kLPt.3,Ch.2 - 1.2.2(Table 2.1.1)
Higher Tensile StrengthFactor - For LocalStrength
k
Spacing for SecondaryStiffeners (mm) s Pt.4, Ch.1 - 1.5
Spacing for PrimaryMembers (m) S
Wave Head CW7.71x10^-2xLxe^(-0.0044L)
Scantling ReductionFactor above Neutral Axis
FD Pt.3, Ch.4 - 5.7.2
1(a)
Scantling ReductionFactor below Neutral Axis FB
Department of Marine Technology, FKM, UTM. 2005
Calculation Sheet – Shell Plating - 2
NO ITEM (unit) SYMBOL FORMULA INPUT CALCULATIONRESULT
DESIGN REF
f1f1 =1/(1+(s/1000S)^2)
hT2 hT2 = (T+0.5CW)
But hT2 <= 1.2T
s1s1 = s but not lessthan
470+L/0.6 or
700mm Whicheverless
L1 L1 = L but <= 190
RB Bilge Radius (mm)
Pt.4, Ch.1 - 5.3.1(Table 1.5.2)
hT1 hT1 = (T+CW)
But hT1 <= 3.6T
1(b) Preliminary Calculation
FMFM the greater betFD and FB
Pt.4, Ch.1 - 5.4.1(Table 1.5.3)
Calculation Sheet – Deck Stiffening - 1
STRUCTURAL DESIGN CALCULATION SHEET – DECK STIFFENING
NO ITEM (unit) SYMBOL FORMULA INPUTCALCULATION
RESULT DESIGN REF
Basic Input DataMaterial Factor - For HullGirder kL
Material Factor - ForLocal Strength
k
Pt.3,Ch.2 - 1.2.2(Table 2.1.1)
Spacing for SecondaryStiffeners (mm) s
1
Relative Density(Tonnes/m^3) Rho not to lee than 1.025
Pt.4, Ch.1 - 1.5
2 : Strength / Weather Deck LongitudinalsOutside Line of Opening
Section Modulus (cm^3) ZZ=0.043xsxkxhT1xle^2xF1
Pt.4, Ch.1 - 4.3.1(Table 1.4.3)
hT1 = L1/56 fo B-60ShiphT1 = L1/70 for B Shipor 1.2 whicever greaterL1 = L but <= 190le = span length >= 1.5 Pt.3, Ch.3 - 3F1 = 0.25C1C1 = 60/(225-165FD)
2(a)
FD = Scant ReductionFactor Pt.3, Ch.4 - 5.7.2
Department of Marine Technology, FKM, UTM. 2005
Calculation Sheet – Deck Stiffening - 2
NO ITEM (unit) SYMBOL FORMULA INPUTCALCULATION
RESULT DESIGN REF
4 : Deck Beams for Strength/weather, Cargo and Accomodation DeckStrength / Weather Decks
Section Modulus (cm^3) ZZ =(K1K2TD+K3B1sh1le^2)k/10^4 or
Pt.4, Ch.1 - 4.3.5(Table 1.4.5)
Z = 2K3B1skh1le^2/10^4K1 = Factor based onDeck No1 Deck = 202 Decks = 13.33 Decks = 10.54 decks or more = 9.3K2 = Factor based onLocationBridge & Poop = 133Elsewhere = 530K3 = Factor based onBeamAdjacent to Ship Side =3.6Elsewhere = 3.3B1 = B but <= 21.5
h1 = Weather HeadPt.3, Ch.3 - 5.2.1(Figure 3.5.2)
4(a)
le = span length >= 1.8 Pt.3, Ch.3 - 3
Department of Marine Technology, FKM, UTM. 2005
Calculation Sheet - Stiffener Section Modulus - 1
Department of Marine Technology, FKM, UTM. 2005
FACEPLATE
WEB PLATE
BASE (ATTACHED) PLATE
bf
tf
twdw
tp
b
SECTION IDEALIZATION FOR CALCULATION OF SECTION MODULUS
Calculation Sheet - Stiffener Section Modulus - 2
STRUCTURAL DESIGN CALCULATION SHEET – LONG/FRAME/STIFFENER SECTION MODULUS
NO ITEM (unit) SYMBOL FORMULA INPUTCALCULATION
RESULT DESIGN REF
1 Face Plate Area (cm^2) a bf*tf/100
bf (mm) = Flange Width
tf (mm) = Flange Thickness
2 Web Depth (mm) dw
3 Web Thickness (mm) tw
See Figure Above
4 Base Plate Area (cm^2) A 10*f*b*tpPt.3, Ch.3- 3.2.7
f = 0.3*(l/b)^(2/3) But <= 1.0Pt.3, Ch.3- 3.2.1 (Table3.3.1)
l (m) = (Dist of Primarysupport) Pt.3, Ch.3 - 3.2.1
b (m) = (Stiff Spacing)Pt.3, Ch.3- 3.2.1 (Fig3.3.2)
(l/b) = Ratio
tp (mm) = Base PlateThickness
Pt.3, Ch.3 - 3.2.1
5Section Modulus BuiltSection (cm^3) Z
a*dw/10 + tw*dw^2/6000 +(1+(200*(A-a)) /(200*A+tw*dw))
Pt.3, Ch.3 - 3.2.6
6Moment of Inertia aboutBase With AttachedPlating (cm^4)
Ia[bf*tf*(tf/2+dw+tp)^2 +(tw*dw^3)/12 + tw*dw*(dw/2+tp)^2] /10^4
Required in Pt.3,Ch.4 - 7.3 (Table3.3.1)
Department of Marine Technology, FKM, UTM. 2005
Calculation Sheet – Hull Girder Section Modulus - 1
STRUCTURAL DESIGN CALCULATION SHEET – HULL GIRDER SECTION MODULUS
L t Z A 1st Mmt 2nd Mmt Io Angle hNO STRUCTURE
DESCRIPTION (m) (mm) (m From Keel) (m.mm) (m2.mm) (m3.mm) (m3.mm)Type
(deg) (m)
∑∑ A ∑∑1st Mmt ∑∑2nd. Mmt ∑∑ Io
Department of Marine Technology, FKM, UTM. 2005
Calculation Sheet – Hull Girder Section Modulus - 2
Actual/Design Section Modulus
FORMULA ITEM VALUE UNIT VALUE UNIT
(a) ∑∑ A Total Area = m.mm
(b) ∑∑1st Mmt Total 1st. Moment = m2.mm
( c) (b)/(a) Dist of NA from Keel = m
(d) ∑∑2nd. Mmt Total 2nd. Moment = m3.mm m2.cm2
(e) ∑∑Io Total Io = m3.mm m2.cm2
(f) (d) + (e) Total I about Keel = m3.mm
(g) (f) – (a)*(c)2 Total I about NA = m3.mm
(h) Measure Height of Deck = m
(i) (h) – ( c) or (c )whichever greater
Max y (ydeck or Ykeel) = or m
(j) (g) / (i) Section Modulus (Half) = m2.mm
(k) (j) x 2 Section Modulus (Full) = m2.mm
Required Section Modulus (Lloyds Rules)
SM required = m2.mm
SF = SM actual / SM required =
Department of Marine Technology, FKM, UTM. 2005
Calculation Sheet – Hull Bending Strength - 1
STRUCTURAL DESIGN CALCULATION SHEET – HULL BENDING STRENGTH
NO ITEM (unit) SYMBOL FORMULA INPUT CALCULATIONRESULT DESIGN REF
1 Basic Input Data Pt.3,Ch.4 - 5.1.1Higher Tensile Strength Factor -For Hull Girder kL
Pt.3,Ch.2 - 1.2.2(Table 2.1.1)
Higher Tensile Strength Factor -For Local Strength k
Ship Service Factor f1 f1 >= 0.5
f1 =1.0 forUnrestricted Sea-going
Wave Bending Moment Factor f2f2 = -1.1 for saging (-ve) Moment
f2 = 1.9Cb/(Cb+0.7)for Hogging
Pt.3,Ch.4 - 5.1.1
2 : Design Value
2(a) Design of Vertical Wave BM
Mw for restricted (KN-m)Mw(sagging)
Mw = f1f2Mwo Pt.3,Ch.4 - 5.2.1
Mw(Hogging)
Mw = f1f2Mwo
Mwo (Kn-m)
Mwo =0.1C1C2L^2B(Cb+0.7)
Yahya Samian, Dept. of Marine Technology, FKM, UTM. 2005
Calculation Sheet – Hull Bending Strength - 2
C1 for L <90 C1 = 0.0412L +4
C1 for L90-300
C1 = 10.75-((300-L)/100)^1.5
C1 for300<L<=350
C1 = 10.75
C1 for350<L<=500
C1 = 10.75-((L-350)/150)^1.5
Pt.3,Ch.4 - 5.2.1(Table 4.5.1)
C2 forMidship C2 = 1.0 Pt.3,Ch.4 - 5.2.2
Mw for Sheltered Water (KN-m)Mw(sagging) Mw = 0.5f2Mwo
Mw(hogging) Mw = 0.5f2Mwo
Mw for short Voyage (KN-m)Mw(sagging)
Mw = 0.8f2Mwo
Mw(hogging) Mw = 0.8f2Mwo
Pt.3,Ch.4 - 5.2.2 -5.2.4
Yahya Samian, Dept. of Marine Technology, FKM, UTM. 2005
Calculation Sheet – Hull Bending Strength - 3
NO ITEM (unit) SYMBOL FORMULA INPUT CALCULATIONRESULT DESIGN REF
2(b) Design Still Water BM
Accurate (KN-m) MsCalculate Directly fromLoading
Still Water BMCalculation
Approximate (KN-m) MsMs = Cs L^2.5B(Cb +0.5)*9.81
Ship Design Book- Tanker
Cs =[0.618+(110 –L)/462]/100
for 61 <= L <=110 m
2( c) Design Section Modulus
SM at Deck (m^3) ZDDirectly CalculatedFrom Midship
SM at Base (m^3) ZBDirectly CalculatedFrom Midship
For Definition ofLong ContinuousSee Pt.3,Ch.3 -3.4
Yahya Samian, Dept. of Marine Technology, FKM, UTM. 2005
Calculation Sheet – Hull Bending Strength - 4
NO ITEM (unit) SYMBOL FORMULA INPUT CALCULATIONRESULT DESIGN REF
3 : Minimum or Permissible Value
3(a) Min Hull Section Modulus
Min Hull SM (m^3) ZminZmin =f1kLC1L^2B(Cb+0.7)/10^6
3(b) Permissible Still Water Bending Moment
Still Water BM (KN-m)Ms Bar(Sagging)
Ms Bar =FDxSigmaxZDx10^3 - MwMs Bar =FBxSigmaxZBx10^3 - MwWhicever Less
Ms Bar(Hogging)
Ms Bar =FDxSigmaxZDx10^3 - MwMs Bar =FBxSigmaxZBx10^3 – MwWhicever Less
FD (Start)
FB (Start)
Sigma(N/mm^2) Sigma = 175/kL
Pt.3,Ch.4 - 5.5 -5.6
Yahya Samian, Dept. of Marine Technology, FKM, UTM. 2005
Calculation Sheet – Hull Bending Strength - 5
NO ITEM (unit) SYMBOL FORMULA INPUT CALCULATIONRESULT DESIGN REF
Local Scantling ReductionVertical Bending Stress atDeck SigmaD
SigmaD =(Msbar +Mw)/ZD x 10^-3 Pt.3,Ch.4 - 5.7
Vertical Bending Stress atBase SigmaB
SigmaB =(Msbar +Mw)/ZB x 10^-4
Reduction Factor at Deck FD FD = SigmaD/sigma
3( c)
Reduction Factor at Base FB FB = SigmaB/sigma4 : Strength Assessment
Section Modulus Criteria COMPLIANCESection Modulud SafetyFactor
SF1 SF1 = ZD/Zmin or Acceptable4(a)
SF1 = ZB/Zmin whichever Less
Still Water BM criteria
Still Water BM Safety Factor SF2SF2 = Msbar/Ms(hogging) OR Acceptable
4(b)SF2 = Msbar/Ms(Sagging) ORWhichever Less
Reduction Factor CriteriaReduction Factor SF3 for plating SF3 = FD/0.67 or Aceptable
SF3 = FB/0.67whichever Less
SF3 forLongitudinals SF3 = FD/0.75 or Not Acceptable
4( c)
SF3 = FB/0.75Whichever Less
Use FB = 0.75 forLongitudinals
Yahya Samian, Dept. of Marine Technology, FKM, UTM. 2005
Calculation Sheet – Hull Buckling Strength - 1
STRUCTURAL DESIGN CALCULATION SHEET – HULL BUCKLING STRENGTH
NO ITEM (unit) SYMBOL FORMULA INPUTCALCULATION
RESULT DESIGN REF
Basic Input Data
Spacing for SecondaryStiffeners (mm) s
Spacing for PrimaryMembers (m)
SPt.4, Ch.1 - 1.5
Modulud of Elasticity(N/mm^2) E E = 206000 For Steel
Specified Min Yield Stress(N/mm^2) SigmaO SigmaO = 235
Specific Sheer Stress lamOlamO =sigmaO/sqrt(3)
Pt.3,Ch.4 - 7.2.1
Higher Tensile StrengthFactor - For Hull Girder kL
Pt.3,Ch.2 - 1.2.2(Table 2.1.1)
1
Higher Tensile StrengthFactor - For LocalStrength
k
Department of Marine Technology, FKM, UTM. 2005
Calculation Sheet – Hull Buckling Strength - 2
NO ITEM (unit) SYMBOL FORMULA INPUTCALCULATION
RESULT DESIGN REF
2 : Elastic Critical Buckling Stress For PlatingPlating With Longitudinal StiffenersOriginal Plate thickness(mm) t
Selected Plating /Stiffeners Pt.3,Ch.4 - 7.2.1
Standard Deduction forCorrosion (mm) dt
One side exposed -Vertical Plate (mm)
dt = 0.05t (Range 0.5 -1 mm)
One Side Exposed -Horizontal Plate (mm)
dt = 0.1t (Range 2 -3mm)
Two side exposed -Vertical Plate (mm)
dt = 0.1t (Range 2 -3mm)
Two Side Exposed -Horizontal Plate (mm)
dt = 0.15t (Range 2 - 4mm)
Pt.3,Ch.4 - 7.2.1(Table 4.7.1)
2(a)
Plate Thickness afterDeduction tp t - dt Pt.3,Ch.4 - 7.2.1
(i) Critical Buckling Stress(N/mm^2)
SigmaE SigmaE = 3.6E(tp/s)^2
(ii) Critical Shear Stress(N/mm^2) LamE
LamE = 3.6[1.335+(s/1000S)^2] x E(tp/s)^2
Pt.3,Ch.4 - 7.3.1(Table 4.7.2)
(iii) 50 % of SigmaO 1/2sigmaO (ii) exceed (iii)Correction Required(ia) Critical Buckling Stress SigmaCR sigmaCR = SigmaO x
(1 - sigmaO/4sigmaE)
(iia) Critical Shear Stress LamCRLamCR = LamO x(1 -LamO/4LamE)
Pt.3,Ch.4 - 7.3.1(Table 4.7.2)
Department of Marine Technology, FKM, UTM. 2005
Calculation Sheet – Hull Buckling Strength - 3
NO ITEM (unit) SYMBOL FORMULA INPUTCALCULATION
RESULT DESIGN REF
3 : Elastic Critical Buckling Stress For Longitudinals
3(a) Section / Longitudinal Properties
Face Plate Area (cm^2) a a = bf*tf/100 See Figure Above Flange Width (mm) bfFlange Thickness afterDeduction (mm)
tf
Web Depth (mm) dwWeb Thickness (mm) twBase Plate Area (cm^2) A 10*f*b*tp Pt.3, Ch.3 - 3.2.7
FactorD ff = 0.3*(l/b)^(2/3) But<= 1.0
Pt.3, Ch.3 -3.2.1(Table 3.3.1)
Distance of PrimarySupport (m) l Pt.3, Ch.3 - 3.2.1
Stiffener Spacing (m) bPt.3, Ch.3 - 3.2.1(Fig 3.3.2)
Ratio (I/b) (l/b)Base Plate Thickness AfterDeduction (mm) tp Pt.3, Ch.3 - 3.2.1
Total Area (cm^2) At A + a + (tw*dw)/100
Section Modulus BuiltSection (cm^3)
Z
a*dw/10 +tw*dw^2/6000 +(1+(200*(A-a)) /(200*A+tw*dw))
Pt.3, Ch.3 - 3.2.6
Department of Marine Technology, FKM, UTM. 2005
Calculation Sheet – Hull Buckling Strength - 4
Inertia Mmt includingBace Plate (cm^4) Ia
bftf(dw+tp)^2 +twdw^3/12 + twdw(dw/2 + tp) +b/4x(tp)^3
St Venant's Inertia Mmtfor Flat Bars (cm^4) It It = dwtw^3/3 x 10^-3
St Venant's Inertia Mmtfor Section (cm^4)
It = 1/3[dwtw^3+bftf^3 x (1 - 0.63tf /bf)] /10^4
Polar Inertia Mmt for FlatBar (cm^4) Ip Ip = dw^3tw/3 x 10^-4
Polar Inertia Mmt forSection (cm^4)
Ip =( dw^3tw/3 +dw^2bftf) /10^4
Sectorial Inertia Mmt FlatBar (cm^4) Iw
Iw = dw^3tw^3 /(36x10^6)
Sectorial Inertia Mmt TeeSection (cm^4)
Iw = tfbf^3dw^2 /(12x10^6)
Sectorial Inertia Mmt forOther (cm^4)
Iw = p x (q+r)/10^6
p = bf^3dw^2 /(12x(bf+dw)^2)q = tf (bf^2 +2bfdw+4dw^2)
r = 3twbfdw
Pt.3, Ch.4 - 7.3(Table 4.7.3)
Department of Marine Technology, FKM, UTM. 2005
Calculation Sheet – Hull Buckling Strength - 5
NO ITEM (unit) SYMBOL FORMULA INPUTCALCULATION
RESULT DESIGN REF
3(b) Elastic Critical Buckling Stress
(i)Column Buckling Stress(N/mm^2) SigmaE
SigmaE = 0.001ExIa /(AtxS^2)
(ii)Torsional Buckling Stress(N/mm^2)
SigmaEsigmaE =0.001EIw(m^2+k/m^2)/(ipS^2) + 0.385EIt/Ip
(iii)Web Buckling Stress(N/mm^2)
SigmaESigmaE = 3.8E(tw/dw)^2
kk = 1.03CS^4 x 10^4 /EIw
Spring Stiffeness CC = kpEtp^3 / [3s(1+1.33kpdwtp^3)/ stw^3]
kp kp = 1-ypyp yp = sigmaA / SigmaEP
SigmaEPas critical buckling stressof plate
Pt.3, Ch.4 - 7.3(Table 4.7.3)
mto be selected fromTable 4.7.3
(iv) 50 % of SigmaO 1/2sigmaO(i), (ii) and (iii)exceeds (iv)
Department of Marine Technology, FKM, UTM. 2005
Calculation Sheet – Hull Buckling Strength - 6
Correction Required
(ia)Critical Column BucklingStress (N/mm^2) SigmaCR
sigmaCR = SigmaO x(1 - sigmaO/4sigmaE)
(iia)CriticalTorsional BucklingStress (N/mm^2)
SigmaCRsigmaCR = SigmaO x(1 - sigmaO/4sigmaE)
(iiia)Critical Web BucklingStress (N/mm^2) SigmaCR
sigmaCR = SigmaO x(1 - sigmaO/4sigmaE)
NO ITEM (unit) SYMBOL FORMULA INPUTCALCULATION
RESULT DESIGN REF
4 : Design Stress
Longitudial CompressiveStress (N/mm^2)Minimum CompressiveStress
SigmaA SigmaA = 30/kL
Minimum CompressiveStress above NA SigmaA sigmaA = sigmaDxZ/ZD
Minimum CompressiveStress Below NA SigmaA sigmaA = sigmaBxZ/ZB
4(a)
Vertical Distance from NAto structure Z Measure from dwg
Shear StressInitial estimation DesignShear Stress LamA LamA = 110/kL
4(b)Accurate Design ShearStress LamA Based on Part 3, Ch 4, 6
Pt.3, Ch.4 - 7.4
Department of Marine Technology, FKM, UTM. 2005
Calculation Sheet – Hull Buckling Strength - 7
NO ITEM (unit) SYMBOL FORMULA INPUTCALCULATION
RESULT DESIGN REF
5 : Strength Assessment
5(a) Scantling criteria for platePlate Buckling Factor Beta Beta = 1 Pt.3, Ch.4 - 7.5Design Buckling Stress SigmaR Beta x sigmaA COMPLIANCECritical Buckling Stress SigmaCR as in 2(a) - (ia)Safety Factor SF SigmaCR/sigmaRDesign Shear Stress LamA as in 4(b)Critical Buckling ShearStress LamCR as in 2(a) - (iia)
Safety Factor SF SF = LamCR/LamA
5(b)Scantling criteria forLongitudinal Pt.3, Ch.4 - 7.5
Longitudinal BucklingFactor Beta Beta = 1.1
Design Buckling Stress SigmaR Beta x sigmaACritical Column BucklingStress SigmaCR as in 3(b) - (ia)
Safety Factor SF SigmaCR/sigmaRCriticalTorsional BucklingStress SigmaCR as in 3(b) - (iia)
Safety Factor SF SigmaCR/sigmaRCritical Web BucklingStress
SigmaCR as in 3(b) - (iiia)
Safety Factor SF SigmaCR/sigmaR
Department of Marine Technology, FKM, UTM. 2005
NO ITEM (unit) SYMBOL FORMULA INPUT CALCULATION DESIGN REF
Department of Marine Technology, FKM, UTM. 2005
SHEET NO : OF :CALCULATED BY : DATE :