ssc-367 - Ship Structure Committee

incorporates inspection-strategy(References4.21, 4.22 and 4.23).
As a result, the design effort must incorporate consideration of
global response, alternate load paths, local stress distributions,
structural detailing, material selection, fabrication procedures,
etc., to ensure that the structure’s fatigue sensitivity is
minimized. However, the extent of the fatigue analysis is a
function of cost as well as technical considerations. A marine
structure costing $1 million and another costing $50 million will
not be analyzed to the same extent. In lieu of extensive analysis,
approximate analysis combined with greater safety factors is
appropriate for less costly structures.
A fatigue criteriadocument maybe very general, stating the design
and analysis objectivesand the classificationand/or certification
requirements. It can also list every method to be implemented and
every assumption to be made in the execution of fatigue analysis.
Most often the document will specify the scope of work, define
overall methodology, and provide the data necessary for fatigue
analysis.
A typical fatigue design and analysis criteria table of contents
contains the following elements:
1. INTRODUCTION
1.1 Objectives
1.2 Scope
1.3 Third Party Inputs
2. MODELLING
2.1 Loads Model
2.2 Mass Model
2.3 Stiffness Model
3. OCEAN ENVIRONMENT
3.1 Applicable Sea States
3.2 RecommendedWave Theories
3.3 Wave Directionality and Distribution
3.4 Wave Scatter Diagrams and Recorded Data
3.5 Wave Spectra
4. PRELIMINARYANALYSIS
4.1 Applicable Method
4.2 Accuracy of Results
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