advanced structural and pipework analysis

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.Fatig Process

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)