Skip to content

There are numerous challenges related to the structural design of offshore topsides and bottom-fixed installations

Sesam has all the facets to support owners and engineers to document code compliance and to optimize the design for cost and performance.

In today’s advanced offshore platform constructions, significant investment is spent on designing, modelling, and analysing the platforms themselves. This represents a substantial financial commitment to offshore wind and O&G production. Using Sesam, it is possible to confidently build and assess complex offshore structural systems. This allows you to guarantee that your structural design conforms to industry design standards and regulations. 

We believe success relies on the ability to have engineering workflows that allow for continuous increase in the fidelity of analytical data models and analyses from options study through conceptual design, basic design and detailed design yielding confidence in the compliance, safety and structural integrity of new and ageing structures.


Software for supporting the structural design and operation of bottom-fixed offshore installations

DNV has developed Sesam for decades to overcome the challenges owners and engineers are exposed to when designing bottom-fixed offshore installations like topsides, substations, jackets for O&G, jack-ups, subsea templates, bridges and secondary structural steel. Sesam is also used by agencies to verify and certify the structural design prior to construction and installation.

The software facilitates a complete and user-friendly process covering all the phases in the initial design from option studies to transportation and installation. For all phases, ultimate strength and fatigue analysis can be carried out with focus on design iterations to ease the work to optimize the design.

Sesam offers a specialized method for analysing the structural strength of fixed offshore platforms. The structural analyses (ULS, FLS, SLS, ALS) during design and operation can be done according to the industry standards API/AISC, ISO/Eurocode and Norsok/Eurocode. Sesam can also do lifecycle and pre-service analyses.

The unique conceptual modelling approach in Sesam allows for fast creation of structural models and to easily modify them during design iterations or operations. It facilitates dynamic update of the connections, the applied loads, the analysis model and the code check capacity details. Re-design is very fast based on modification of section properties, material properties or buckling parameters – all confirmed by an automated full re-run updating the mass and stiffness properties.

The analysis capabilities includes stochastic (frequency), deterministic and time domain approaches. Both linear static and dynamic analyses may be carried out where the loads are either manually defined or automatically created for waves, current and wind.

Great for:

  • Design offshore structures that can withstand the impacts of the wave, wind, current, and seismic stresses in the location where they are to be used
  • Structural design of offshore bottom-fixed installations like substations, jackets, jack-ups, sub-sea templates and their topsides, equipments, flarebooms, helidecks and bridges
  • Structural strength analysis inclusive of detailed stress analysis for 3D model data
  • Strength analysis (ULS and SLS)
  • Fatigue analysis (FLS)
  • Earthquake analysis
  • Boat impact and accidental analysis (ALS)
  • Material Take Off report (MTO)
  • Version control of model data and results – and web-based sharing with stakeholders