Critical components, systems and structures can exhibit problems or issues at any time during their service lives. New ones can break down prematurely or fail to function as designed, older ones can incur long-term wear or damage or fail as a result of other unidentified causes, or changes to design or operation of a system can result in a need to understand how the current condition of the component, system or structure will affect performance.

Structural Integrity can evaluate such situations using a multidisciplinary approach that includes materials specialists, analytical engineers, and a broad technical staff that is familiar with assessing existing conditions and making recommendations or overseeing changes to critical components, systems or structures. Our range of analytical services can support inspection planning, serviceability assessment, remaining life prediction, repair/replacement guidance, and design and certification evaluations of critical equipment.

The tools for engineering analysis include application of closed-form equations to specific problems, finite element stress analysis (including modelling of thermal transients), fracture mechanics, online monitoring, probabilistic analyses, and relative risk assessment. These tools can be applied to a wide variety of components, systems and structures including:

  • Headers and Drums
  • Welds/DMWs
  • Nozzles
  • Piping
  • Turbine Rotors/Disks
  • Boiler Tube Assemblies
  • Valves
  • Pressure Vessels
  • Fittings
  • Steam Chests
  • Structural Components
  • Fasteners/Bolts
  • Subsea HPHT Components
  • Critical Structures and Facilities
PWSCC 02Finite element analysis is a critical tool for engineering assessment that requires knowledge of industry software, accurate modelling and meshing methods, and application of appropriate boundary conditions. Applied loads and stresses, including thermal transients, can be assessed by applying linear elastic, elastic-plastic, and inelastic creep stress analyses for situations where engineering design or life assessment must be evaluated. For example, dynamic analysis of piping systems and other components, systems and structures can be performed to evaluate the effects of dynamic events (e.g., seismic, water/steam hammer, vibration, thermal fatigue, wind, blast, etc.), or finite element analysis can be used to model welding processes to evaluate residual stresses due to weld overlay or other repair methods.
Computational Fluid Dynamics or CFD Modelling is used to evaluate internal and external flow in boilers, HRSGs, and piping systems. Evaluations are often performed using COSMOS, FloWork, and ANSYS CFX software.
Fracture Mechanics is used to evaluate critical flaw size, leak before break, and crack growth expectations in situations where fatigue, corrosion-fatigue, stress corrosion cracking, creep, and creep-fatigue are occurring. These evaluations for serviceability are normally performed per API 579, ASME FFS-1, ASME Section XI, and other industry standards.
Soil and Fluid Structure Interaction is used to evaluate the response of partially or fully buried or immersed structures to seismic loads. Software tools such as SASSI are used for these evaluations. Other tools such as ABAQUS can be used to calculate the dynamic response of the structures to these external loads.
Remaining Life Assessment is often performed using component specific codes such as the EPRI BLESS software for headers and piping, DMW-PODIS for tubing dissimilar metal welds, pc-SAFER for turbine rotors, RRing-life for generator retaining rings, LP-Rimlife for turbine disks, and MPC OmegaPipe for high energy piping girth and seam welds. Other methodologies can also be applied for less common assessments. When engineering assessments are needed, having a broad range of capabilities and experience is critical to obtaining the best overall results. The engineering staff at SI understands the team approach and the importance of accurate results.

For additional information on our Engineering Analysis Services, as applied to the markets we serve, click on the links above below or contact .