FS-OffFat is a series of program modules that interface with FS2000 for the deterministic fatigue analysis of framed structures under cyclic loading due to the action of hydrodynamic waves.
Outline Procedure
- FS-Wave - WaveLoader steps each characteristic wave through the structure. Up to 14 phase increments.
- SCF Evaluation - SCFs evaluated at up to 12 circumferential locations (stress points) on brace and chord side.
- Stress Range - Peak stress range evaluated at all stress points.
- Stress Range/Wave Ht - For different wave heights log-linear interpolation is used to define a Stress Range/Wave Ht curve for each stresspoint.
- Wave Spectrum - Weibull probability function or user defined wave exceedence data define wave exceedence diagram.
- SN Curves - Standard SN curves or user defined curves are used in conjunction with Miners Rule to evaluate damage ratios. Directional Distribution factors used.
Simple Operation
All Modules run in batch mode. A control file utility program creates all load cases and control files used in the fatigue analysis.
- Joint Recognition - Automatic recognition of Chord and Brace members
- Classification - Automatic Joint Classification (T/Y, K, X etc) based on geometry. Gap evaluation for K joints.
- Non-Tubular Joints - Stress ranges at standard nodes using defined SCF.
- SCF Evaluation Utility - Automatic SCF evaluation based on program evaluated parameters and SCF category. Evaluation utility for sensitivity studies on SCF parameters.
- UEG Kuang, Wordsworth/Smedley
- DEn Guidance Notes
- DNV/API/EC3/ISO 1434 Ethymiou Parametric Equation
- User Defined Re-Classification
All program evaluated parameters including SCFs may be re-defined using user defined classifications and parameters.
- SN Curves - Standard or user defined curves.
- Optional Fracture Mechanics Module - BS7910-Approach using
Selective Output
- Graphical - Damage Ratio Plots Selective plots - Show only low lives
- Sorted Summary - Sort by Life Rating
- Restricted Output- Limit Output to Defined Criticality Limit (Life threshold)