1、 GUIDE FOR SAFEHULL-DYNAMIC LOADING APPROACH FOR VESSELS DECEMBER 2006 Guide to Color Coding Used in Online Version of the Guide The following summarizes the colors corresponding to Rule Changes, Corrigenda items and editorial changes in the Guide files which are available for download. Rule Changes
2、: NOTICE NO. 1 August 2013 (effective 1 August 2013) NOTICE NO. 2 October 2015 (effective 1 October 2015) Corrigenda: CORRIGENDA/EDITORIALS 1 August 2013 CORRIGENDA/EDITORIALS 1 February 2014 Editorials: Editorial Changes Guide for SafeHull-Dynamic Loading Approach for Vessels GUIDE FOR SAFEHULL-DYN
3、AMIC LOADING APPROACH FOR VESSELS DECEMBER 2006 (Updated October 2015 see next page) American Bureau of Shipping Incorporated by Act of Legislature of the State of New York 1862 Copyright 2010 American Bureau of Shipping ABS Plaza 16855 Northchase Drive Houston, TX 77060 USA Updates October 2015 con
4、solidation includes: February 2014 version plus Notice No. 2 February 2014 consolidation includes: August 2013 version plus Corrigenda/Editorials August 2013 consolidation includes: December 2006 version plus Notice No. 1 and Corrigenda/Editorials ABSGUIDE FOR SAFEHULL-DYNAMIC LOADING APPROACH FOR V
5、ESSELS .2006 iii Foreword Foreword This Guide provides information about the optional classification notation, SafeHull-Dynamic Loading Approach, SH-DLA, which is available to qualifying vessels intended to carry oil in bulk, ore or bulk cargoes, containers and liquefied gases in bulk. In the text h
6、erein, this document is referred to as “this Guide”. Section 1-1-3 of the ABS Rules for Conditions of Classification (Part 1) contains descriptions of the various basic and optional classification notations available. The following Chapters of the ABS Rules for Building and Classing Steel Vessels (S
7、teel Vessel Rules) give the design and analysis criteria applicable to the specific vessel types: Part 5C, Chapter 1 Tankers of 150 meters (492 feet) or more in length Part 5C, Chapter 3 Bulk carriers of 150 meters (492 feet) or more in length Part 5C, Chapter 5 Container carriers of 130 meters (427
8、 feet) or more in length Part 5C, Chapter 8 LNG carriers Part 5C, Chapter 12 Membrane Tank LNG Vessels In addition to the Rule design criteria, SafeHull-Dynamic Loading Approach based on first-principle direct calculations is acceptable with respect to the determination of design loads and the estab
9、lishment of strength criteria for vessels. In the case of a conflict between this Guide and the ABS Steel Vessel Rules, the latter has precedence. This Guide is a consolidated and extended edition of: Analysis Procedure Manual for The Dynamic Loading Approach (DLA) for Tankers, March 1992 Analysis P
10、rocedure Manual for The Dynamic Loading Approach (DLA) for Bulk Carriers, April 1993 Analysis Procedure Manual for The Dynamic Loading Approach (DLA) for Container Carriers, April 1993 Guidance Notes on SafeHull-Dynamic Loading Approach for Container Carriers, April 2005 This Guide represents the mo
11、st current and advanced ABS DLA analysis procedure including linear and nonlinear seakeeping analysis. This Guide is issued December 2006. Users of this Guide are welcome to contact ABS with any questions or comments concerning this Guide. Users are advised to check periodically with ABS to ensure t
12、hat this version of this Guide is current. iv ABSGUIDE FOR SAFEHULL-DYNAMIC LOADING APPROACH FOR VESSELS .2006 Table of Contents GUIDE FOR SAFEHULL-DYNAMIC LOADING APPROACH FOR VESSELS CONTENTS SECTION 1 General 1 1 Introduction . 1 3 Application . 1 5 Concepts and Benefits of DLA Analysis . 1 5.1 C
13、oncepts . 1 5.3 Benefits 2 5.5 Load Case Development for DLA Analysis 2 5.7 General Modeling Considerations 3 7 Notations . 3 9 Scope and Overview of this Guide . 3 FIGURE 1 Schematic Representation of the DLA Analysis Procedure . 5 SECTION 2 Load Cases . 6 1 General . 6 3 Ship Speed 6 5 Loading Con
14、ditions . 6 5.1 Tankers 6 5.3 Bulk Carriers 7 5.5 Container Carriers . 7 5.7 LNG Carriers . 7 7 Dominant Load Parameters (DLP) . 7 7.1 Tankers 7 7.3 Bulk Carriers 9 7.5 Container Carriers . 9 7.7 LNG Carriers . 11 9 Instantaneous Load Components . 11 11 Impact and Other Loads . 12 13 Selection of Lo
15、ad Cases . 12 FIGURE 1 Positive Vertical Bending Moment 7 FIGURE 2 Positive Vertical Shear Force 8 FIGURE 3 Definition of Ship Motions . 8 FIGURE 4 Positive Horizontal Bending Moment 10 FIGURE 5 Reference Point for Acceleration 10 ABSGUIDE FOR SAFEHULL-DYNAMIC LOADING APPROACH FOR VESSELS .2006 v SE
16、CTION 3 Environmental Condition . 13 1 General . 13 3 Wave Scatter Diagram 13 5 Wave Spectrum 13 TABLE 1 IACS Wave Scatter Diagrams for the North Atlantic . 14 FIGURE 1 Definition of Wave Heading 14 SECTION 4 Response Amplitude Operators . 15 1 General . 15 3 Static Loads 15 5 Linear Seakeeping Anal
17、ysis 16 5.1 General Modeling Considerations . 16 5.3 Diffraction-Radiation Methods . 16 5.5 Panel Model Development 16 5.7 Roll Damping Model 16 7 Ship Motion and Wave Load RAOs 16 SECTION 5 Long-term Response . 17 1 General . 17 3 Short-term Response 17 5 Long-Term Response . 18 SECTION 6 Equivalen
18、t Design Wave 19 1 General . 19 3 Equivalent Wave Amplitude 19 5 Wave Frequency and Heading . 19 7 Linear Instantaneous Load Components 20 9 Nonlinear Pressure Adjustment near the Waterline . 20 11 Special Consideration to Adjust EWA for Maximum Hogging and Sagging Load Cases . 21 FIGURE 1 Determina
19、tion of Wave Amplitude 20 FIGURE 2 Pressure Adjustment Zones 21 SECTION 7 Nonlinear Ship Motion and Wave Load 22 1 General . 22 3 Nonlinear Seakeeping Analysis 22 3.1 Concept . 22 3.3 Benefits of Nonlinear Seakeeping Analysis . 22 5 Modeling Consideration 22 5.1 Mathematical Model 22 5.3 Numerical C
20、ourse-keeping Model . 23 7 Nonlinear Instantaneous Load Components 23 vi ABSGUIDE FOR SAFEHULL-DYNAMIC LOADING APPROACH FOR VESSELS .2006 SECTION 8 External Pressure . 24 1 General . 24 3 Simultaneously-acting External Pressures . 24 5 Pressure Loading on the Structural FE Model 24 FIGURE 1 Sample E
21、xternal Hydrodynamic Pressure for Maximum Hogging Moment Amidships . 24 SECTION 9 Internal Liquid Tank Pressure . 25 1 General . 25 3 Pressure Components 25 5 Local Acceleration at the CG of Tank Content . 26 7 Simultaneously-acting Tank Pressure 26 FIGURE 1 Internal Pressure on a Completely Filled
22、Tank . 26 FIGURE 2 Internal Pressure on a Partially Filled Tank 26 SECTION 10 Bulk Cargo Pressure 27 1 General . 27 3 Definitions . 27 5 Pressure Components 28 5.1 Static Pressure 28 5.3 Dynamic Pressure . 28 7 Local Acceleration at the CG of Tank Content . 31 9 Simultaneously-acting Bulk Cargo Load
23、 . 31 FIGURE 1 Definition of Wall Angle 27 FIGURE 2 Definition of Positive Tangential Component of Bulk Cargo Pressure 27 FIGURE 3 Static Pressure due to Gravity 28 FIGURE 4 Dynamic Pressure due to Vertical Acceleration 29 FIGURE 5 Dynamic Pressure due to Transverse Acceleration 30 SECTION 11 Contai
24、ner Load . 32 1 General . 32 3 Load Components . 32 3.1 Static Load . 32 3.3 Dynamic Load 32 5 Local Acceleration at the CG of a Container 33 7 Simultaneously-acting Container Load . 34 FIGURE 1 Dynamic Load due to Vertical and Transverse Acceleration 33 ABSGUIDE FOR SAFEHULL-DYNAMIC LOADING APPROAC
25、H FOR VESSELS .2006 vii SECTION 12 Load on Lightship Structure and Equipment 35 1 General . 35 3 Load Components . 35 3.1 Static Load 35 3.3 Dynamic Load . 35 5 Local Acceleration . 36 7 Simultaneously-acting Loads on Lightship Structure and Equipment . 36 SECTION 13 Loading for Structural FE Analys
26、is 37 1 General . 37 3 Equilibrium Check . 37 5 Boundary Forces and Moments 37 SECTION 14 Structural FE Analysis . 38 1 General . 38 3 Global FE Analysis 38 5 Local FE Analysis . 38 5.1 Tanker . 38 5.3 Bulk Carrier . 39 5.5 Container Carrier . 39 5.7 LNG Carrier . 39 7 Fatigue Assessment . 39 SECTIO
27、N 15 Acceptance Criteria 40 1 General . 40 3 Yielding . 40 3.1 Field Stress . 40 3.3 Local Stress . 41 3.5 Hot-Spot Stress . 41 3.7 Allowable Stress for Watertight Boundaries 41 3.9 Allowable Stresses for Main Supporting Members and Structural Details . 41 5 Buckling and Ultimate Strength 42 TABLE 1
28、 Allowable Stresses for Watertight Boundaries 41 TABLE 2 Allowable Stresses for Various FE Mesh Sizes (Non-tight Structural Members) . 42 APPENDIX 1 Summary of Analysis Procedure 43 1 General . 43 3 Basic Data Required . 43 5 Hydrostatic Calculations . 43 7 Response Amplitude Operators (RAOs) . 44 9
29、 Long-Term Extreme Values 44 11 Equivalent Design Waves . 44 viii ABSGUIDE FOR SAFEHULL-DYNAMIC LOADING APPROACH FOR VESSELS .2006 13 Nonlinear Seakeeping Analysis 45 15 External Pressure . 45 17 Internal Liquid Tank Pressure . 45 19 Bulk Cargo Pressure . 45 21 Container Loads 45 23 Loads on Lightsh
30、ip Structure and Equipment . 45 25 Loadings for Structural FE Analysis 46 27 Global FE Analysis 46 29 Local FE Analysis . 46 31 Closing Comments 47 APPENDIX 2 Buckling and Ultimate Strength Criteria . 48 1 General . 48 1.1 Approach . 48 1.3 Buckling Control Concepts 48 3 Plate Panels 48 3.1 Buckling
31、 State Limit . 48 3.3 Effective Width . 49 3.5 Ultimate Strength . 49 5 Longitudinals and Stiffeners 50 5.1 Beam-Column Buckling State Limits and Ultimate Strength 50 5.3 Torsional-Flexural Buckling State Limit 51 7 Stiffened Panels 51 7.1 Large Stiffened Panels Between Bulkheads 51 7.3 Uniaxially S
32、tiffened Panels between Transverses and Girders . 51 9 Deep Girders and Webs . 52 9.1 Buckling Criteria. 52 9.3 Tripping 52 APPENDIX 3 Nominal Design Corrosion Values (NDCV) for Vessels 53 1 General . 53 TABLE 1 Nominal Design Corrosion Values for Tankers . 54 TABLE 2 Nominal Design Corrosion Values
33、 for Bulk Carriers . 56 TABLE 3 Nominal Design Corrosion Values for Container Carriers 58 TABLE 4 Nominal Design Corrosion Values for Membrane LNG Carriers . 60 FIGURE 1 Nominal Design Corrosion Values for Tankers . 53 FIGURE 2 Nominal Design Corrosion Values for Bulk Carriers . 55 FIGURE 3 Nominal
34、Design Corrosion Values for Container Carriers 57 FIGURE 4 Nominal Design Corrosion Values for Membrane LNG Carriers . 59 ABSGUIDE FOR SAFEHULL-DYNAMIC LOADING APPROACH FOR VESSELS .2006 1 Section 1: General SECTION 1 General 1 Introduction The design and construction of the hull, superstructure and
35、 deckhouses of an ocean-going vessel are to be based on all applicable requirements of the ABS Rules for Building and Classing Steel Vessels (Steel Vessel Rules). The design criteria of the Steel Vessel Rules are referred to as ABS SafeHull criteria. The SafeHull criteria in the Steel Vessel Rules e
36、ntail a two-step procedure. The main objective of the first step, referred to as Initial Scantling Evaluation (ISE), is scantling selection to accommodate global and local strength requirements. The scantling selection is accomplished through the application of design equations that reflect combinat
37、ions of static and dynamic envelope loads; durability considerations; expected service, survey and maintenance practices; and structural strength considering the failure modes of material yielding and buckling. Also, a part of ISE is an assessment of fatigue strength primarily aimed at connections b
38、etween longitudinal stiffeners and transverse web frames in the hull structure. The second step of the SafeHull criteria, referred to as Total Strength Assessment (TSA), entails the performance of structural analyses using the primary design Loading Cases of ISE. The main purpose of the TSA analyses
39、 is to confirm that the selected design scantlings are adequate (from a broader structural system point of view) to resist the failure modes of yielding, buckling, ultimate strength and fatigue. The SafeHull-Dynamic Loading Approach (SH-DLA) provides an enhanced structural analyses basis to assess t
40、he capabilities and sufficiency of a structural design. A fundamental requirement of SH-DLA is that the basic, initial design of the structure is to be in accordance with the SafeHull criteria as specified in the Steel Vessel Rules. The results of the DLA analyses cannot be used to reduce the basic
41、scantlings obtained from the direct application of the Rule criteria scantling requirements (see 3-1-2/5.5.5 of the Steel Vessel Rules). However, should the DLA analysis indicate the need to increase any basic scantling, this increase is to be accomplished to meet the DLA criteria. 3 Application Thi
42、s Guide is applicable to ocean-going vessels of all size and proportions including tankers, bulk carriers, container carriers and LNG carriers. Specifically for a container carrier with length in excess of 350 meters (1148 feet), the hull structure and critical structural details are to comply with
43、the requirements of this SafeHull-Dynamic Loading Approach (5C-5-1/1.3.3 of the Steel Vessel Rules). 5 Concepts and Benefits of DLA Analysis 5.1 Concepts DLA is an analysis process, rather than a step-wise design-oriented process such as SafeHull criteria. The DLA Analysis emphasizes the completenes
44、s and realism of the analysis model in terms of both the extent of the structure modeled and the loading conditions analyzed. The DLA modeling and analysis process relies on performing multiple levels of analysis that start with an overall or global hull model. The results of each previous level of
45、analysis are used to establish which areas of the structure require finer (more detailed) modeling and analysis, as well as the local loads and boundary conditions to be imposed on the finer model. The Load Cases considered in the DLA Analysis possess the following attributes: i) Use of cargo loadin
46、g patterns, other loading components and vessel operating drafts that reflect the actual ones intended for the vessel (note that the Load Cases in SafeHull comprise mainly those intended to produce scantling design controlling situations). ii) Load components that are realistically combined to assem
47、ble each DLA Analysis Load Case. The dynamically related aspects of the components are incorporated in the model, and the combination of these dynamically considered components is accommodated in the analysis method. Section 1 General 2 ABSGUIDE FOR SAFEHULL-DYNAMIC LOADING APPROACH FOR VESSELS .200
48、6 5.3 Benefits The enhanced realism provided by the DLA analysis gives benefits that are of added value to the Owner/Operator. The most important of these is an enhanced and more precise quantification of structural safety based on the attributes mentioned above. Additionally, the more specific know
49、ledge of expected structural behavior and performance is very useful in more realistically evaluating and developing inspection and maintenance plans. The usefulness of such analytical results when discussing the need to provide possible future steel renewals should be apparent. A potentially valuable benefit that can arise from the DLA analysis is that it provides access to a comprehensive and authoritative structural evaluation model, which may be readily employed in the event of emergency situations that might
