Strength Calculations

You need to know — with certainty — that your structure can carry its intended loads, pass certification and perform safely throughout its service life. We deliver the documented proof: clear, standards-compliant strength calculations that satisfy your engineering team, your clients and the certifying authorities. Using analytical methods and Finite Element Analysis, we assess stresses, deformations and stability margins so you can move forward without uncertainty.

Problems we solve

Our clients come to us with challenges that range from a single component that keeps failing in the field to a complete offshore structure that needs third-party verification before commissioning. Typical projects include:

  • Verifying a new design before prototyping — catch stress concentrations, excessive deflections or stability issues before committing to fabrication.
  • Obtaining certification or permit approval — produce the documented calculations required by notified bodies, classification societies or building authorities.
  • Investigating field failures — determine the root cause of cracks, permanent deformations or collapses and recommend corrective design changes.
  • Assessing modifications to existing structures — verify that added loads, cut-outs or extensions do not compromise the original safety margins.
  • Reducing material cost and weight — demonstrate through calculation that a lighter design still meets all code requirements, avoiding unnecessary over-dimensioning.
  • Resolving disagreements between engineering parties — provide an independent, well-documented second opinion to break an impasse.

What we assess

Every structure has a critical failure mode and we make sure none of them are overlooked. Our strength calculations cover:

  • Static stress assessment — we verify that material stresses remain below the allowable limits under all relevant load combinations, using the safety factors prescribed by the applicable design code.
  • Stiffness and serviceability — we check that deflections and deformations stay within acceptable tolerances, because a structure that is strong enough can still be rejected if it deforms too much to function properly.
  • Buckling and stability — we evaluate the risk of sudden, uncontrolled loss of stability in slender members under compressive or shear loading, including nonlinear buckling with geometric imperfections where required by the code.
  • Fatigue screening — for structures under repetitive loading, we identify fatigue-critical locations and assess whether a detailed fatigue analysis is needed.
  • Creep assessment — for components operating at elevated temperatures, we evaluate the risk of progressive deformation over the intended service life.

How we work

Choosing the right method for your project

Not every problem requires a full Finite Element model. For straightforward geometries and loading we use analytical hand calculations — faster, transparent and often exactly what a certification body expects. When the geometry is complex, when multiple load combinations need to be evaluated or when the design code explicitly requires it, we use FEA to obtain the detailed stress and deformation fields that hand calculations cannot provide. We always recommend the approach that gives you the best balance of accuracy, turnaround time and acceptance by the relevant authorities.

Design by Rules and Design by Analysis

Most design codes offer two paths. The traditional Design by Rules (DBR) uses simplified formulae and tabulated safety factors — reliable and widely accepted, but sometimes overly conservative. Design by Analysis (DBA) uses FEA-based verification, which is especially valuable when DBR forces you into an unnecessarily heavy or expensive design, or when your geometry or loading falls outside the scope of the standard formulae. We are experienced in both approaches and will guide you to the one that makes the most sense for your situation.

What you receive

Every project results in a professional calculation report that is ready for review by your client, a notified body or a classification society. Our reports include a clear description of the model, loads and boundary conditions, the applicable code clauses, detailed results with contour plots where relevant, and an unambiguous pass/fail conclusion per check. We write our reports so that they can be followed and verified by third parties — because that is exactly what a certification process demands.

Standards and codes we work with

We routinely perform strength calculations according to the following international standards. If your project requires a code not listed here, please ask — our experience covers a broad range of industry-specific rules and guidelines.

Eurocode standards

  • EN-1990 (Eurocode 0): Basis of structural design
  • EN-1991 (Eurocode 1): Actions on structures
  • EN-1992 (Eurocode 2): Design of concrete structures
  • EN-1993 (Eurocode 3): Design of steel structures
  • EN-1994 (Eurocode 4): Design of composite steel and concrete structures
  • EN-1995 (Eurocode 5): Design of timber structures
  • EN-1996 (Eurocode 6): Design of masonry structures
  • EN-1997 (Eurocode 7): Geotechnical design
  • EN-1998 (Eurocode 8): Design of structures for earthquake resistance
  • EN-1999 (Eurocode 9): Design of aluminium structures

Offshore industry

  • ISO 19900 series: Design of offshore structures for the oil & gas industry
  • DNV-GL: Design of offshore structures for oil & gas and offshore wind
  • NORSOK: Design of offshore structures for oil & gas
  • API: Design of offshore structures for oil & gas

Pressure vessels

  • ASME VIII Div.2
  • EN 13445

Weld design and assessment

  • IIW
  • AWS

Need a strength calculation for your project?

Whether you need to verify a new design, obtain certification, investigate a failure or get an independent second opinion — we deliver clear, well-documented calculation reports that stand up to scrutiny from clients, notified bodies and classification societies.

Get in touch for a free initial discussion. We will review your requirements, identify the applicable standards and provide you with a clear project proposal.

 Contact us  or call us at +32 478 618 118

Frequently asked questions

Common questions about strength calculations and code compliance.

We use Ansys Mechanical and Nastran for Finite Element Analysis, complemented by Matlab and Python for analytical calculations, post-processing and automated report generation. We also maintain in-house tools that streamline code checks against specific standards. The choice of software depends on the project; what matters most is selecting the right analysis method and applying the correct standard — that is where our expertise lies.

Design by Rules follows prescriptive formulas from a standard — for example minimum wall thicknesses for a pressure vessel shell. It is straightforward but conservative, because the rules must cover a wide range of geometries. Design by Analysis uses Finite Element Analysis to evaluate the actual stress state in your specific geometry against detailed acceptance criteria defined in the standard. It is more work, but often allows you to demonstrate that a lighter or more efficient design still meets the requirements. We advise on which approach makes the most sense for your situation.

We routinely work with Eurocode (EN-1990 through EN-1999), offshore and marine standards (ISO 19900 series, DNV-GL, NORSOK, API), pressure vessel codes (ASME VIII Div.2, EN 13445) and weld assessment frameworks (IIW, AWS). If your project involves a different standard, ask us — our engineers are experienced in interpreting and applying a wide range of national and international codes.

Simple, standardised geometries (a cylindrical pressure vessel, a bolted connection per Eurocode) can often be assessed with hand calculations. FEA is needed when the geometry is complex, when loads are not uniform, when multiple load cases interact, or when the standard explicitly requires a Design by Analysis approach. We always choose the simplest method that is appropriate for the problem — using FEA where it adds value, not where a hand calculation would suffice.

Yes. Our reports are structured to meet the documentation requirements of notified bodies, classification societies and independent third-party reviewers. They contain clear descriptions of the model, loads, boundary conditions, material data and acceptance criteria, followed by the results and an unambiguous pass/fail conclusion. We have experience with reviews from DNV, Lloyd's, Bureau Veritas, TÜV and others.

Absolutely. We regularly investigate field failures, assess modifications to existing structures and perform remaining-life evaluations. This includes determining root causes of cracking or deformation, checking whether a proposed repair or reinforcement is adequate, and advising on whether continued operation is safe. A clear engineering assessment can resolve disagreements between parties and provide the documented evidence needed for regulatory approval of continued use.

We need the geometry (CAD, drawings or as-built dimensions), the materials and their specifications, the loads your structure will experience (including combinations and safety factors if defined by the applicable code), and the standard or set of acceptance criteria the design must meet. If you are unsure about the applicable code or load cases, we can advise on that as well.