Frequently asked questions

SP-8007 gives a single empirical lower bound fitted to test data from the 1960s. Skalnav's MDC approach derives knockdown factors mechanistically from geometry, imperfection measures and buckling regime — and shows you the experimental evidence behind each curve. You can display both side by side in every analysis.

Skalnav computes and documents knockdown factors alongside nine established design codes, with full traceability of the underlying evidence. Whether a mechanistic KDF is admissible as the primary basis of a proof depends on your project's verification plan and approval authority — that decision always stays with them. Typical uses are justifying margins, quantifying the conservatism of code values, and cross-checking a primary method against the experimental record.

Statistical bases for the design curve, analogous in spirit to material allowables: alongside the mean (best-estimate) curve, Basis B is the empirical 10th percentile of the underlying Monte-Carlo ensemble (conservative) and Basis A the empirical 1st percentile (highly conservative). They are quantile-based conservative approximations — not strict MIL-HDBK-5 tolerance limits — and the methodology notes state this explicitly. You choose the basis to match your project's reliability requirements.

From six decades of published collapse experiments — 1,000+ curated records in the ValidationHub with documented provenance for every data point, measured values strictly separated from assumed bounds.

Geometries: cylinders, cones, spherical shells (shallow cap through complete sphere), torispherical heads, and cone–cylinder assemblies; ellipsoidal and toroidal shells are available through the NASA SP-8032 module. Plain and sandwich walls; ring-stiffened cylinders under external pressure.

Load cases: axial compression, global bending, torsion, transverse shear, external pressure and wind, plus combined cases (axial + bending, axial or bending + internal pressure, axial + external pressure, torsion combinations) and dedicated silo and tank workflows.

Not every combination carries a native MDC curve yet — where it doesn't, the nine implemented design codes cover the case. The authoritative, always-current view is the coverage matrix.

On-premise and air-gapped deployment is on our enterprise roadmap and evaluated per engagement — contact us to discuss requirements, availability and timelines.

The platform is hosted on servers located in Germany (IONOS SE) under a data processing agreement; all assets are served self-hosted — no third-party CDNs or trackers. Details, including your rights and retention periods, are in the privacy policy.

Yes — watch the demo, download the sample verification report, or open Skalnav directly in your browser: cylinder axial and bending work without a login.

Beyond that, a Proof of Value (from €15,000) runs Skalnav against an agreed real design case from your own programme and documents the result, and the Startup Program lowers the entry cost for qualifying early-stage companies.

Professional is €9,900 per year for one named user. Team is €29,900 per year for up to five named users. An Enterprise Design Partnership starts at €75,000 per year and is scoped individually. All prices are per year and exclude VAT.

For a group between Team and Enterprise, Business / Department covers up to about ten named users at €49,900 per year — ask us for a quote.

No. Every commercial licence runs the same released engineering core: the same methods, the same design bases (mean, B-Basis, A-Basis), the same applicability warnings and the same safety factors. We do not sell a more accurate answer at a higher price.

The tiers differ in how many engineers use the tool, whether they share an organisation and projects, the level of support, and how much integration, qualification or custom engineering work is included.

Yes. Every commercial licence — Professional included — permits commercial use, and the results of your own engineering work may be delivered to your clients. There is no separate client-deliverable licence.

What is not permitted: sharing an account, reselling or sublicensing access to Skalnav, letting your client operate the tool on your licence, and redistributing the underlying Skalnav databases, knockdown-factor tables or software.

Yes — 30-Day Professional Project Access at €1,699 (excl. VAT) gives you the full Professional engineering core for one named user for 30 days. It does not renew: there is no subscription to cancel, and the licence simply ends. You get the same released methods, design bases and export formats as the annual licence, with no analysis or report limits added just because the term is short.

It is a short-term alternative to the annual licence, not the standard way to buy Skalnav: from roughly six 30-day blocks onward the annual licence is cheaper, and continuous professional use is expected to run on an annual licence. Project Access is arranged directly with us: contact us.

Yes. Upgrade to Professional Annual during the active 30-day access period and the full €1,699 Project Access fee is credited toward your first annual licence — €9,900 less the €1,699 credit leaves €8,201 to pay. The list price of Professional stays €9,900 per year; this is an upgrade credit for what you already paid, not a discount.

Credit terms: the Project Access must still be active when you order the annual licence; the credit is applied once, for the same legal entity that holds the Project Access, and multiple Project Access purchases do not accumulate; the maximum credit is the €1,699 fee; it is applied against the first Professional annual licence and is not paid out in cash or combined with other credits. VAT follows the actual invoice.

Team or broader organisational upgrades can be arranged with Skalnav directly — write to us and we will apply the equivalent credit commercially.

Academic covers education, teaching and non-commercial research. It is granted automatically for recognised institutional e-mail domains; other addresses start on the registered Explorer tier and can request Academic via Feedback.

Any commercial, contract or client work — including funded industry projects carried out at an institution — needs a Professional licence. Academic accounts are limited to the mean design basis and watermarked export, and the Validation Hub, Imperfection Hub and Imperfection Guide are Professional features.

Yes. The Skalnav Startup Program is temporary adoption support for qualifying independent early-stage companies: Professional at €4,900 in year one and €7,400 in year two, Team at €14,900 in year one and €22,400 in year two, then standard pricing from year three.

Startup licences carry the same engineering scope and the same commercial rights as the corresponding standard tier — it is a lower price, not a smaller product. We generally look for an independent company that is not part of a larger corporate group, younger than five years and under 100 employees; Skalnav reviews each application and decides the level of support case by case.

A licence is the answer when your own engineers do the work and it comes back project after project. Engineering Services are for a single problem that needs independent judgement: a verification you want reviewed from outside, two methods that disagree, a contested imperfection basis or KDF, a review board asking for a second opinion, or a case that goes beyond a standard workflow.

The two support each other: a single review can be the start, with a licence once the workflow is routine — or a licence holder calls on us when a difficult case appears. Engagements from Advanced Buckling Engineering upward include Team access for the project duration, and 25% of the engagement fee is creditable toward a first annual licence.

No. An Independent Buckling Review is an independent engineering opinion within an agreed technical scope, delivered as a written review memorandum. It is not an approval by an authority, and Skalnav does not act as an appointed checking engineer (Prüfingenieur) or issue regulatory certification.

The memorandum states clearly which of the following applies: no material technical objections within the agreed scope; observations and recommendations; points requiring clarification; or that the verification cannot be endorsed within the agreed scope. Whether that evidence is admissible in your verification process is decided by your project's approval authority.

Fixed scope at a fixed project price, agreed in writing before work starts — no hourly billing. The published figures are entry prices: an Independent Buckling Review from €4,500, an Independent Buckling Verification from €9,900, Advanced Buckling Engineering from €15,000, and Method Development & Qualification from €30,000, with full qualification programmes project-priced from €150,000. Training starts at €4,500 and technical talks at €3,500. All excl. VAT.

What moves the price: the number of structures and load cases, how many methods are compared, whether an FE review is included, composite or stiffened construction, documentation depth and the meetings you need. Send a short description of the case and you get a written scope, price and schedule back. Priority scheduling is available by agreement.

Please do not attach proprietary engineering data to a first e-mail. Describe the case in general terms; we then agree how data is exchanged — under an NDA where you need one — before anything technical is sent. NDA available for confidential engineering engagements.