Large Ship

Corrosion Assessment

During FEED, hull conversion, or life extension projects SAGA is used to apply corrosion gaugings that have been entered into a database system developed by Viking Systems. The system uses a 3D model to show gaugings for plates and the webs and flanges of stiffeners and carries out a complete steel renewal procedure using class required substantial thickness calculations, projection of future corrosion and required steel renewal - all shown graphically on a 3D model.Physical Gauging Locations

  • Location of gauging including tank and coordinates
  • Gauged Thickness
  • As-built thickness
  • Protection of Future Anticipated Corrosion
  • Renewal required class steel renewal calculation requirements

Actual corrosion mapped to all structure
SAGA applies the corrosion values by subtracting the FEA model scantlings:

  • Plate thickness
  • Stiffener web thickness
  • Stiffener flange thickness

The model's gauging database is compared and a corroded model is made:

  • As-Built model and database thicknesses are compared and validity checked
  • Plate thickness and stiffener properties are updated
  • Interpolation options for elements away from gaugings
  • Percentage rule minimum corrosion can be applied
  • Diminution corrosion can be subtracted

Resulting FEA Model with as gauged thickness >:

Fracture and Fatigue Cracks

Crack Curve - ChartSAGA is used on fracture mechanics projects where a standard SN Curve approach is not considered appropriate. The fracture mechanics program is based on the Paris' Law approach described in SSC-409 and allows for the evaluation of crack growth of external and internal crack types typically found in ship structures.

The loading driving the fatigue stress ranges are defined by a Weibull distribution of a stress range calculated by loading and solving an FEA model. The model program allows us to investigate the effect of:
Crack Model

  • Initial crack length
  • Residual stress in the structure
  • Compressive stress
  • Wheeler retardation model
  • Shape geometry effects in case of a damaged area

Finite Element Model stress ranges are used in SAGA to calculate a fracture damage ratio where the amount of cycles in a design event is presented as a ratio of the amount of cycles to failure.

Code Compliance Check

Viking Systems SAGA program is constantly at work on ships and offshore structures, providing our teams with design and assessment capabilities on all types of structures primarily on:

  • FPSO and FSO vessels
  • Jackup offshore installations
  • Navy and Coast Guard vessels
  • Ships and barges

SAGA uses built-in design code checking from below regulatory bodies:

  • ABS Steel Vessel Rules
  • ABS FPI Rules
  • ABS MODU Rules
  • ABS HSNC High-Speed Naval Craft
  • BV Parts A-D and NI593
  • API RP 2A
  • DNV OS-C101
  • DNV RP-C201, RP-C203, RP-C205, RP-C206

Results Presentation

Viking Systems SAGA program prepares results for our users and clients using a Virtual Reality Modeling Language (VRML) format viewable in standard web browsers and other programs that read VRML, for example, Rhino. The result files are available for use by information technology interested clients wishing to see the results in interactive 3D rather than simply as shown in reports.

STOOLFEA   Stress View Interior

SAGA Buckling

Results are also available in Femap neutral file format

Contact our highly skilled teams to learn more about what SAGA can do for your maritime project – SAGA is developed to combine hydrodynamic loading and finite element structural analysis and classification society code checks serving clients around the world from our offices in North America, Asia, and Africa.

US: Houston
16290 Katy Freeway, Suite 110
Houston, TX 77094
US: Annapolis
326 First Street Suite 36
Annapolis MD 21403
US: Palm Beach
525 S Flagler Drive 27D
West Palm Beach FL 33401
Africa: Tanzania
Old Mochi Road
Arusha Tanzania
Asia: Singapore
3 Fusionopolis Place #05-53
Singapore 138523