Page 18 - Marine Structural Design

Contents xv

22.3.4 Modification of Residual Stress Distribution ................................................................... 405
22.3.5 Discussions ....................................................................................................................... 405
22.4 Damage Tolerance Criteria ...................................................................................................... 406
22.4.1 General ............................................................................................................................. 406
22.4.2 Residual Strength Assessment Using Failure Assessment Diagram ................................ 406
22.4.3 Residual Life Prediction Using Paris Law ....................................................................... 407
22.4.4 Discussions ....................................................................................................................... 407
22.5 Non-Destructive Inspection ..................................................................................................... 407
22.6 References ............................................................................................................................... 408

Part IV: Structural Reliability
CHAPTER 23 BASICS OF STRUCTURAL RELIABILITY ........................................................ 413

23.1 Introduction ............................................................................................................................. 413
23.2 Uncertainty and Uncertainty Modeling ................................................................................... 413
23.2.1 General ............................................................................................................................. 413
23.2.2 Natural vs . Modeling Uncertainties ................................................................................. 414
23.3 Basic Concepts ........................................................................................................................ 415
23.3.1 General ............................................................................................................................. 415
23.3.2 Limit State and Failure Mode ........................................................................................... 415
23.3.3 Calculation of Structural Reliability ................................................................................ 415
23.3.4 Calculation by FORM ...................................................................................................... 419
23.3.5 Calculation by SOW ...................................................................................................... 420
23.4 Component Reliability .............................................................................................................. 421
23.5 System Reliability Analysis ..................................................................................................... 421
23.5.1 General ............................................................................................................................. 421
23.5.2 Series System Reliability ................................................................................................. 421
23.5.3 Parallel System Reliability ............................................................................................... 421
23.6 Combination of Statistical Loads ............................................................................................. 422
23.6.1 General ............................................................................................................................. 422
23.6.2 Turkstra’s Rule ................................................................................................................. 423
23.6.3 Feny Borges-Castanheta Model ....................................................................................... 423
23.7 Time-Variant Reliability .......................................................................................................... 424
23.8 Reliability Updating ................................................................................................................. 425
23.9 Target Probability .................................................................................................................... 426
23.9.1 General ............................................................................................................................. 426
23.9.2 Target Probability ............................................................................................................. 426
23.9.3 Recommended Target Safety Indices for Ship Structures ................................................ 427
23.10 Software for Reliability Calculations .............................................................................. 427
23.1 1 Numerical Examples ....................................................................................................... 427
23.1 1.1 Example 23.1 : Safety Index Calculation of a Ship Hull ............................................. 427
23.1 1.2 Example 23.2: p Safety Index Method ....................................................................... 428
23.1 1.3 Example 23.3: Reliability Calculation of Series System ............................................ 429
23.1 I . 4 Example 23.4: Reliability Calculation of Parallel System ......................................... 430
23.12 References ....................................................................................................................... 431
CHAPTER 24 RANDOM VARIABLES AND UNCERTAINTY ANALYSIS ............................ 433
24.1 Introduction ............................................................................................................................. 433
24.2 Random Variables ................................................................................................................... 433
24.2.1 General ............................................................................................................................. 433
24.2.2 Statistical Descriptions ..................................................................................................... 433
24.2.3 Probabilistic Distributions ................................................................................................ 434