Design and Structural Integrity Assessment of Offshore and Land-Based Installations Subjected to Extreme Loads

Nowatec is a consulting engineering company specialising in the design and structural integrity assessment of offshore and land-based installations subjected to extreme loads.

The Piper Alpha disaster drew attention to the damage likely to arise from explosions and fires on an offshore platform, and the inadequacies of previous practices in the minimisation of and protection against these hazards.

Nowatec's focus, therefore, is to provide new structural solutions and risk minimisation methods against fires and explosions on offshore and land-based installations.

Nowatec’s key fields of experience include:

  • Structural design and assessments using the non-linear finite element (FE) method
  • Assessment of aerodynamic and fluid-structure interaction using the computational fluid dynamics (CFD) method
  • Hazard engineering, including explosion and fire design
  • Application of new materials

Design procedures for offshore structures

Explosions, fires and other accidents are major risks in the offshore industry. Extreme loads arising from accidents create a challenge for structural engineers in the design of safe and weight-efficient structures. The use of design procedures based on state-of-the-art computational technology allows for weight-optimised structural designs that meet defined safety requirements.

FE modelling for offshore structures resistant to explosions and fires

Design procedures for creating offshore structures resistant to explosions and fires are normally based on the selection of design principles such as deterministic, probabilistic and risk-based design.

Methods used in designing structures that are resistant to explosions and fires include simplified methods and non-linear FE modelling and analysis. FE models involve accurate description of modelling techniques including modelling of structures, materials, and fire and explosion loads.

Assessment of fire and explosion loads

Nowatec performs assessment of fire and explosion loads using state-of-the-art CFD software such as FLACS and Kameleon CFX. Based on assessments of fire and explosion loads, deterministic or probabilistic models of loads are established for direct use in the design process for offshore installations.

Nowatec carries out structural design verification as well as studies of structures subjected to fires and explosions. Complex FE models of structures are developed and used in response and structural strength simulations.

Blast-resistant walls and partitions for offshore structures

The following aspects are normally considered in order to achieve an optimum design of blast-resistant walls and partitions:

  • Definition of design explosion and fire loads
  • Establishment of the behaviour of materials to be used for the design for high rate loads
  • Determination of the behaviour and strength of walls by means of non-linear FE modelling

The structural design and analysis methods developed by Nowatec have been applied in a number of explosion and fire design projects for offshore and land-based facilities.

Offshore gas explosion load assessment

The 'Design of offshore facilities to resist gas explosion hazard – Engineering Handbook', by Dr Jurek Czujko (Nowatec CEO), has been developed based on the results of the Gas Explosion Engineering joint industry project (GEE JIP). The project was sponsored by HSE (UK), Norsk Hydro and STATOIL (Norway).

The major objective of the project was to develop methods and procedures to improve gas explosion load assessment using CFD, and structural behaviour using non-linear finite element methods (NL-FEM). During the project, a number of studies were carried out and documented in the handbook.

Explosion and Fire Engineering of FPSOs JIP

Explosion and Fire Engineering of FPSOs is a joint industry project to produce a documented procedure and guidelines relevant for assessing gas explosions and fire actions (loads), and the resulting consequences (e.g., structural damage) of FPSO topside structures and equipment, as well as associated risk levels.

This new procedure is intended to be applicable to both new and existing structures. It is based on the use of state-of-the-art CFD models for the action analysis, and time-domain non-linear finite element analysis (NLFEA) for the consequence assessment.

The project is carried out by Nowatec in cooperation with Pusan National University, Korea. Partners of the project are: Hyundai Heavy Industry Yards (HHI), Samsung Heavy Industry Yards (SHI), Daewoo Shipbuilding & Marine Engineering (DSME), the American Bureau of Shipping and the Korean Register of Shipping.

Nowatec's performance strategy

Continuous development of technical procedures and design philosophies, participation in joint industry research and development projects, and large investments in computer software and high-performance hardware are key elements of our performance strategy. They, combined with our engineers' extensive knowledge and experience, enable us not only to meet our clients' needs but to exceed their expectations.

Contact us to find out how our design and structural integrity assessment capabilities can be applied to your offshore and onshore projects.

Contact Details

Nowatec AS
Strøket 8
1383 Asker
+47 900 17 054
+47 66 98 86 31