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Rising to the Challenge

Fenix is a full-featured elastic finite element analysis and structural design plug-in for Grasshopper. It is both fast and powerful. Use it for anything from a single beam to a high-rise building, and everything in between!

IMPORTANT: When creating a log-in, you must use the e-mail address that is associated with your McNeel (Rhino) account.

Features at a Glance

Model Complex Geometry

By using Rhino 3D as your modeling environment and leveraging the capabilities of Grasshopper, you can quickly and easily create complex structural models.


Detailed Features


  • Frame elements

    • Timoshenko​

    • Euler-Bernoulli

    • Tension/compression only

  • Shell & membrane elements​​

    • Triangular & quadrilateral

    • Thick & thin

  • Solid elements

    • Pentahedrons

    • Hexahedrons

    • Linear & quadratic​

  • Spring elements

    • Single-node springs​

    • Tension/compression only

  • Link elements

    • Global link​

  • Section cuts

    • Quadrilateral cuts​

    • Surface cuts

    • Section strips


  • Point loads

    • Forces & moments​

    • Imposed displacements

  • Frame loads

    • Varying linear loads

    • Point loads

    • Thermal loads

  • Shell loads

    • Uniform area loads​

    • Varying area loads

    • Uniform thermal loads

  • Solid loads

    • Uniform solid loads​

    • Uniform thermal loads

  • Auto-seismic loads

    • Equivalent lateral force based on ASCE 7-16 or ASCE 41-17​

  • Response spectra


  • Analysis Types​​​

    • Static force (including thermal)

    • Imposed displacement

    • Eigenvalue (modal)

    • Response spectrum

  • Iterative Analysis

    • Tension/compression only for frames and springs

    • Frame P-Delta

  • Computational Performance

    • Multi-threaded architecture speeds up analysis and post-processing

    • Stores everything in memory for faster computation and access to results


  • Design Code Checks

    • Run prescriptive code-based design checks using IBC 2018 and associated material-specific codes

    • Check detailing requirements for certain seismic systems

  • Fiber Section

    • Check concrete frame designs using built-in non-linear fiber-section analysis

  • Calculation Reports

    • Design calculations as linked HTML files that can be printed to PDF

    • Printed using LaTex and Markdown in a user-friendly & easy-to-read format

view results

  • View in Rhino via the Model Preview component

  • Results for individual load combinations

  • Element properties and modifiers

  • Elements by user-assigned groups, or turn elements on/off by type

  • Displacements with scale

  • Shell & solid stresses

  • Frame force & moment diagrams

  • Reactions

  • Animated mode shapes

  • Color results by gradients

  • Demand-to-capacity ratios (DCRs)


  • Dozens of custom Grasshopper components

  • Create elements from Rhino or Grasshopper geometry

  • Buttons and forms reduce the number of component inputs

  • Manipulate element geometry and properties with built-in components

  • Retrieve analysis results with a host of specialized components

  • Customize the units for results display

  • Filter and manipulate lists with utility components

View the Wiki

for all of our components


  • Although Fenix is closed-source, a majority of its public methods are accessible via the API

  • Develop your own customized add-on components by referencing the Fenix DLLs in your project.

  • Take advantage of our forums to ask specific programming related questions

  • Share your developments with other users in the Fenix community

View the API

for API documentation


  • Numerous tests have been performed on all element formulations to ensure accuracy

  • We don't like black boxes and believe that as much information as possible should be provided to the user

  • All element formulations and their references have been thoroughly documented on our Wiki

View the Wiki

for finite element theory and element formulations

system requirements

  • 64 bit Windows operating system

  • 8GB memory, though 16GB+ is recommended, with 32GB - 64GB optimal for running large models

  • Fenix stores the model and results in memory...the more memory you have, the larger models you can run

  • Quad-core processor (8-threads) or better, clocked at 2.0GHz or higher

  • Open GL capable graphics card

  • Internet connection

View Rhino Req's

for Rhino & Grasshopper system requirements

The future

We don't promise any new features or improvements. We don't claim that you will like this product. We don't guarantee that results obtained using Fenix are correct.

What we can do is tell you we are passionate about this product. It has been in development for years and we love improving it. We will do our very best to fix bugs quickly, add new features often, expand the design capability, and improve on the user experience.

We are not random people working for a large software company. We are two people who care about this product.


Complex Structures
Parametric Solids
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