Terms of Use

1Agreement to these terms

These Terms of Use (“Terms”) are a legal agreement between you and Zydeno, the developer of Trussbeck (“we”, “us”). They apply to the Trussbeck app for Android, its updates and everything it shows or produces (together, “the app”). By installing, opening or using the app you accept these Terms. If you do not accept them, do not use the app and uninstall it.

The Privacy Policy explains how the app handles data and forms part of these Terms. If we offer optional features under additional terms in the future, for example paid features, those terms will be shown to you before you accept them and will apply together with these Terms.

You must be old enough to enter into a binding contract where you live, or use the app with the consent and supervision of a parent or guardian who accepts these Terms for you. If you use the app for an organisation, you confirm that you may accept these Terms on its behalf; the consumer-protection provisions of these Terms apply only to consumers.

2Who provides Trussbeck

Trussbeck is developed and published by Zydeno (“we”, “us”), an independent developer. Contact: support@zydeno.com, website zydeno.com.

The app is a technical and educational tool intended for adults and students. If you are under the age of majority where you live, use it only with the involvement of a parent or guardian.

3What Trussbeck is and is not

Trussbeck is a tool for studying and for preliminary analysis of two-dimensional beams, trusses and frames. From the model, supports, loads, sections and materials you enter, it calculates support reactions, internal forces (axial force, shear force and bending moment), deflections, extreme-fibre stresses and section properties, draws diagrams, shows solution steps and prepares an analysis report. It works offline, has no ads and needs no account.

Trussbeck is not a design tool and not an engineering service. It does not check members, connections or foundations against design codes such as Eurocode, AISC 360 or SP 16.13330, and design codes are named only to say that it does not check against them. It does not size members, contains no catalogues of real steel or timber profiles and no strength classes of materials (the material constants it offers are typical values that you should edit for your material), and gives no verdict such as “OK”, “safe” or “pass”. An analysis report is a record of a calculation for your model; it is not a design calculation, a certificate, or a sealed or stamped document, and it is not suitable on its own for a building permit, building control or any approval.

4Study and preliminary analysis only

• Model assumptions. The app assumes linear-elastic material, small displacements, static loads and a first-order analysis with Euler–Bernoulli members unless the model says otherwise. It does not check buckling or other instability, second-order (P-Δ) effects, dynamics or vibration, plasticity, local buckling, fatigue, connections, foundations or the soil. Real structures can behave very differently from such a model.
• Warnings are not a check. The app warns about some modelling problems, such as mechanisms, poor conditioning or very large deflections. The absence of a warning does not mean that a model, a load or a result is correct or adequate.
• Solution steps show how the app’s results are obtained for teaching purposes. They are not an independent verification of those results.
• Loads and factors are yours. The app contains no loads, load combinations or safety factors from any code. You choose every load and factor and are responsible for them.
• In many countries the design of structures may only be carried out or approved by qualified or licensed professionals. Using the app does not make you one and does not replace one.

5Your responsibility

You are responsible for:

• the model you build: geometry, supports, releases, sections, material constants and loads, entered correctly in the units you selected;
• choosing assumptions, loads, load combinations and factors that suit your purpose, and recording their sources;
• checking results independently before relying on them, and having any real structure designed and checked by a qualified engineer;
• complying with the laws, building regulations, design codes and professional rules that apply where you work, and with the rules of your school or university for coursework and exams;
• any reports, images, files or advice you provide to clients, employers, teachers or authorities, and the consequences of using them.

6Methods and file formats

The analysis uses the authors’ own implementation of published structural-analysis theory (the direct stiffness method, equilibrium, the method of joints and of sections, the force method and the three-moment equation where they apply). Textbooks are cited in the app under “Theory & references” for further reading; the app contains no text, figures, tables or worked problems copied from books or from other software. Method names such as Euler–Bernoulli, Macaulay, Pratt, Howe or Warren are used only to name methods and truss types.

Trussbeck exports PDF reports, CSV tables, PNG images and its own JSON project format, and reads its own project and backup files. Exported reports and images carry a note that they come from a linear-elastic analysis that must be verified independently; do not remove it. Check imported and exported data in your other software before relying on it.

7Not professional advice; no safety-critical use

The app is a tool to help you plan and calculate. It does not give professional, engineering, legal or other expert advice, and using it does not create a professional relationship with us. You remain responsible for your inputs, for how you interpret the results and for what you decide to do.

Do not use the app as the only basis for a decision where an error could cause death, personal injury, damage to property or the environment, or legal or financial loss, and do not use it in a safety-critical system, in an emergency or to control equipment. Trussbeck does not check members against design codes, and its results are not a design check, a sealed or stamped calculation or approval for any permit.

8Licence to use the app

Subject to these Terms, we grant you a limited, personal, revocable, non-exclusive, non-transferable and non-sublicensable licence to download, install and use the app on Android devices you own or control, for your own purposes (study, teaching, research and preliminary analysis). The app is licensed to you, not sold.

Except where these Terms, an open-source licence or mandatory law allow it (for example decompiling for interoperability where the law permits), you may not: copy, modify, translate or create derivative works of the app; decompile, disassemble or reverse-engineer it; rent, lend, sell, sublicense, distribute or publish it, or make it available for use by others over a network; remove or change any copyright, trademark or legal notice; or get around any technical limit of the app, including any future purchase, licence or advertising mechanism.

Open-source components and fonts in the app are licensed under their own licences, listed in the app under About → Open-source licenses. Those licences prevail for those components, and nothing in these Terms limits the rights they give you.

9Your data and backups

Your projects, your section and material library and your settings are stored only on your device. You own them. We do not have a copy and cannot recover them if you lose your phone, uninstall the app, clear its storage or use “Delete all data”. Use “Export data” in Settings to keep your own copy. See the Privacy Policy for details.

The models, reports and files you create are yours to use, subject to §4. We claim no rights in them.

10Fonts and open-source components

Trussbeck is built with open-source software and fonts, shown in the app under About → Open-source licenses:

The fonts and libraries remain the property of their authors. Nothing in these Terms limits the rights those licences give you for those components.

11Acceptable use

You agree not to:

• use the app in breach of any law or of other people’s rights;
• remove or hide the analysis note or legal notices from reports and images, or present the app’s output as a design check, a code-compliance verdict, a certified, sealed or stamped calculation or an official document;
• submit the app’s output as your own independent work where the rules of your school, university or employer do not allow it;
• copy, modify, redistribute, sell or reverse-engineer the app, except as allowed by law or by an open-source licence.

12Intellectual property

The app, its design, text, solution templates, icon and the name Trussbeck belong to the developer, except for the open-source components and the fonts above, which belong to their owners. Names of design codes, standards and methods are used only to describe things and belong to their respective owners.

13Price, payments, ads and future paid features

Current version. The current version of Trussbeck is provided free of charge, without ads and without in-app purchases or subscriptions. This describes the current version only. It is not a promise that the app, or any feature of it, will remain free of charge or free of ads.

Possible changes. We may at any time introduce advertising; offer paid features, in-app purchases, subscriptions or a paid edition; change which features are free; and set or change prices. Features that are free today may require payment in a future version. We will describe such changes in the store listing and release notes, and in the Privacy Policy where they affect data.

Purchases. Any purchase will be made through Google Play and processed by Google under the Google Play Terms of Service and its payment policies. Prices are shown in Google Play before you buy, including taxes where applicable. Subscriptions renew automatically until you cancel them in Google Play; cancelling stops future renewals. Refunds follow Google Play’s refund policies and your mandatory consumer rights, such as the right of withdrawal in the EU and the UK. Where you ask for immediate access to digital content during a withdrawal period, you may lose that right to the extent the law allows, and you will be asked to confirm this before you buy. You are charged only if you choose to buy something.

Ads. If the app shows ads, they are supplied by third parties. We are not responsible for the content of ads or for the products and services advertised, and any dealings with advertisers are between you and them.

Price changes. We may change prices for future purchases at any time. For an active subscription, we will announce a price increase as Google Play and the law require, and you can cancel before it applies.

14Disclaimer of warranties

To the maximum extent permitted by law, the app and everything it produces are provided “as is” and “as available”, without warranties of any kind, express or implied, including warranties of accuracy, reliability, fitness for a particular purpose, merchantability and non-infringement. We do not warrant that the app is free of errors, that calculated reactions, forces, diagrams, deflections, stresses, section properties or solution steps are correct or suitable for your purpose, that a structure analysed with the app is adequate or complies with any code, that exported files open correctly in your other software, or that the app will work on every device or Android version.

15Limitation of liability

To the maximum extent permitted by law, the developer is not liable for any indirect, incidental, special, consequential or punitive damages, or for design errors, damage to or failure of structures, buildings or other property, rework, delays, the cost of labour, equipment or materials, regulatory, academic or professional consequences, loss of data, lost profits or business losses, arising from or related to the app, its output or decisions based on it, even if we were told such damage was possible. Where mandatory product-liability law applies to the app as software, including the national rules implementing Directive (EU) 2024/2853, this section does not limit that liability (see below).

16Your rights as a consumer

If you use the app as a consumer, you benefit from the mandatory consumer-protection rules of the country where you live, and nothing in these Terms affects them. In particular:

• EU and EEA: your statutory rights, including those on the conformity of digital content and digital services under the national rules implementing Directive (EU) 2019/770 where they apply, and mandatory product-liability rules, remain unaffected.
• United Kingdom: your statutory rights, including under the Consumer Rights Act 2015, remain unaffected.
• Australia: our services come with guarantees that cannot be excluded under the Australian Consumer Law. Where the law allows us to limit our liability for failing to meet a consumer guarantee for services that are not of a kind ordinarily acquired for personal, domestic or household use, our liability is limited to supplying the services again or paying the cost of having them supplied again.
• New Zealand: if you acquire the app for business purposes, you agree that the Consumer Guarantees Act 1993 does not apply, to the extent the law permits.
• United States and Canada: some states and provinces do not allow the exclusion of implied warranties or the limitation of incidental or consequential damages, so some of the exclusions above may not apply to you. In Québec, the mandatory provisions of the Consumer Protection Act apply.

17Indemnity

To the extent permitted by law, you agree to indemnify and hold harmless the developer against claims, liabilities, damages, losses and reasonable costs, including reasonable legal fees, brought by third parties and arising out of (a) structures, designs, reports and coursework you prepare with the app or provide to others, (b) your breach of these Terms, (c) your violation of any law or of the rights of others, or (d) output of the app that you provide to another person, such as a client or employer. This does not apply to the extent a claim is caused by our own breach of these Terms or our negligence, or where local consumer law does not allow it.

18Changes, availability and termination

To the extent the law allows, we may change, update, add or remove features, change data sources, and suspend or discontinue the app, in whole or in part or in any country, at any time. We are not obliged to provide updates, maintenance or support, except where mandatory consumer law requires updates to keep the app in conformity.

You may stop using the app at any time by uninstalling it. Your licence ends automatically if you materially breach these Terms, and we may end or suspend it where the law requires. When it ends, you must stop using the app and uninstall it. Your data stays on your device under your control, so export what you need first.

Provisions that by their nature should continue after these Terms end continue to apply, including those on intellectual property, disclaimers, limitation of liability, indemnity, governing law and general provisions.

19Google Play

You obtain the app through Google Play. Your download, and any purchase you make, is also governed by the Google Play Terms of Service and Google’s policies. Where these Terms conflict with Google Play’s terms on the distribution, billing, refunds or licensing of apps obtained from Google Play, Google Play’s terms prevail to the extent of that conflict.

These Terms are between you and the developer only, not Google. Google is not responsible for the app or its content and has no obligation to provide maintenance or support for it. Android and Google Play are trademarks of Google LLC.

20Governing law and disputes

These Terms, and any dispute or claim arising out of or in connection with them or the app, including non-contractual disputes, are governed by the law of the country in which the developer is established, without regard to its conflict-of-laws rules. The United Nations Convention on Contracts for the International Sale of Goods does not apply.

The courts competent for the place where the developer is established have jurisdiction. If you are a consumer, you keep the protection of the mandatory provisions of the law of your country of residence, and you may bring proceedings in the courts of that country where that law allows it.

Before starting formal proceedings, please write to support@zydeno.com and give us at least 30 days to try to resolve the issue informally. This does not affect any time limit that applies to you by law or your right to use an alternative dispute-resolution body available to consumers in your country.

21General provisions

• Entire agreement. These Terms, the Privacy Policy and any additional terms you accept for optional features are the entire agreement between you and us about the app.
• Severability. If a provision is found invalid or unenforceable, it applies to the maximum extent permitted and the rest remains in effect.
• No waiver. Not enforcing a provision is not a waiver of the right to enforce it later.
• Assignment. You may not transfer your rights or obligations under these Terms. We may transfer ours, for example together with the app to another developer; where the law requires, this will not reduce your rights as a consumer.
• Events beyond our control. We are not responsible for failure or delay caused by events beyond our reasonable control, such as outages of networks, devices or third-party services, natural disasters or acts of authorities.
• Export and sanctions. You agree to use the app in compliance with applicable export-control and sanctions laws.
• No third-party rights. No one other than you and us may enforce these Terms.
• Notices. We may give notices in the app, in its store listing or release notes, or on this page. You can send notices to support@zydeno.com.
• Language. These Terms are written in English, which is the binding version. A translation, if offered, is for convenience only, unless the law of your country requires otherwise.

22Changes to these terms

We may update these Terms, for example when we change the app, introduce ads or paid features (§13), or when the law changes. The effective date and version at the top of this page show which version applies, and the version history (§23) summarises the changes.

For material changes we give reasonable notice before they take effect, for example in the release notes or in the app. If you keep using the app after the changes take effect, you accept the updated Terms; if you do not agree, stop using the app and uninstall it. Changes do not apply to disputes that arose before they took effect.

23Version history

24Contact

• Developer: Zydeno, the developer of Trussbeck on Google Play
• E-mail: support@zydeno.com
• Website: zydeno.com

See also the Privacy Policy.