Stress and Strength Analysis

Stress and Strength Analysis

Kiwa Inspecta provides stress and structural analyses for components and systems such as pressure vessels, piping systems, valves, heat exchangers, steel structures, gear boxes and electronic components. The purpose is to analyse the ability of the component to withstand the loads it is subjected to, with consideration of all possible failure modes of the material, such as yielding, fracture, buckling, fatigue and creep.

The first important step is to identify and analyse all loads that will act on the component during its service life, including static, thermal, and dynamic loading. Loads may be due to, for example, pressure, temperature cycles, wind, snow, waves, earthquake, impact or water hammering. Sometimes manufacturing residual stresses such as weld residual stresses are crucial to the performance of the component.

We use state-of-the-art finite element stress analysis codes and analytical techniques, and efficient pre and post-processing methods. We perform linear and non-linear analyses, depending on what is most efficient and necessary in each case. Examples of codes employed by Kiwa Inspecta are ANSYS, ABAQUS, ADINA, PIPESTRESS, CAEPIPE, VVD and Mathcad. Examples of in-house programs are T‑UTM, used to analyse thermal fatigue, and One‑Therm, used to calculate thermal gradient stresses for piping thermal transients.

We have extensive experience from finite element stress analysis, code application and evaluation of failure modes in equipment for nuclear power plants, process industry and manufacturing industry. The purpose of a stress analysis is usually one of the following:

  • Analysis for verification of equipment design according to codes and standards (e.g. EN 13445, EN 13480, ASME VIII, ASME III, Eurocode). We provide a design report which shows that your design fulfils best-practice and proves compliance with all applicable standards.
  • Optimization of design (or concepts) with respect to aspects as
     –  life-time and performance (e.g. fatigue or stress corrosion resistance), or
     –  manufacturing cost (manufacturing method and weight).
  • Remaining life assessment of safety-critical or production-critical components. When the original design lifetime is reached, or if subjected to more severe service conditions then original design anticipated. 
  • Assessment of defects found in industrial equipment at periodic inspection (for example local wall thinning, pitting, creep damage, weld defect or crack).

We perform industry research and development to investigate the performance of components subjected to high and complicated loads. Our experienced engineers provide an in-depth understanding of materials behavior in industrial applications and have applied its approach on a wide range of assets. For example they help companies show adequate safety levels in low cycle fatigue cases. Evaluation of low cycle fatigue, and also manufacturing processes, often requires detailed constitutive modelling in order to properly capture the non-linear material response (hardening, softening, ratcheting).

Benefits with Stress and Strength Analysis

Leading expertise in evaluation of material failure modes, efficient and relevant stress analyses - the level of analysis is always adapted to fit the purpose, extensive knowledge of standards, reports and solutions.