STKO for OpenSees

STKO | Scientific ToolKit for OpenSees |

STKO (Scientific ToolKit for OpenSees) is a powerful pre and post processor and cutting-edge data visualization tool for OpenSees. By using STKO a user can create a Tool Command Language (TCL) input file for Opensees and an output file readable by its graphic interface. The user can customize and manipulate with a Python-based scripting interface the model input and output to create customized engineering demand parameters and output data. -> watch Video Presentation - DAMAGE TC3D

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Post processing of shell results at gauss points and at through-the-thickness integration points (fibers).

Post processing of beam-column results by means of a fiber-section plot, that allows the user to visualize results such as strain/stress at each fiber of each gauss points of beam-column elements.

Meshing algorithms in STKO OpenSees pre-processor. Global and local edge seed, unstructured and structured mesh algorithms, triangle/tetrahedron, quadrilateral/hexahedron, linear and quadratic interpolations.

Post processing of beam-column results by means of a gauss-point plot, that allows the user to visualize results such at each gauss points of beam-column elements.

STKO OpenSees pre-processing for micro-modeling of masonry structures.

STKO OpenSees Seismic Isolation.

Simulation of Damage Evolution of Pazzi Chapel in Florence, Italy with STKO OpenSees. -> watch Video Presentation - DAMAGE TC3D

This example shows how to model a reinforced concrete shear wall using shell elements and layered shell cross section. -> watch Video Presentation - DAMAGE TC3D


Post-processing of a soil-foundation-structure-interaction problem. Visualization of results on solid elements by means of a volume plot.

Example of absorbing boundaries using the VS3D4 element available in OpenSees.

Comparative study of different approches to simulate absorbing boundaries in soil-structure interaction problems.

3D Analysis of Soil-Pile interaction with contact elements.

Simulation SFSI (Soil Foundation Structure Interaction) with STKO OpenSees.

SFSI: Analysis of the boundary conditions and their application in the case study of a bridge in STKO OpenSees.

WHY Scientific ToolKit for Opensees IS SO INNOVATIVE


… features advanced CAD modeling tools, import-export of common CAD file formats, geometry repair tools, and a comprehensive set of meshing algorithms.

… is easily customizable via a python-based scripting interface. So custom components can be easily specified and added to the standard document, to fit the end-user needs.

… can then produce input files for OpenSees with all the information inputed by the user.


Import-export of open file formats (STEP and IGES)

Curve modeling

Surface modeling

Solid modeling

Interface modeling



Linear | Quadratic


Edge Seed:

Uniform by divisions

Uniform by size

Biased by size and bias factor

Biased by number and bias factor

Dual-biased by size and bias factors


2D un-structured for triangles and quadrilaterals

3D un-structured for tetrahedrons

2D structured for triangles and quadrilaterals

3D structured for hexahedrons



Uniaxial | nD



Beam fiber-section

Shell layered-section


SP constraints

MP constraints


Uniform exitation pattern

Multi-support exitation pattern






… features all common visualization algorithms (edge/surface color map, volume rendering, iso-lines, iso-surfaces, vector plots, etc..). Post processing also includes advanced visualization algorithms for beam/column and shell elements equipped with discretized (fiber) cross sections.

… is easily customizable via a python-based scripting interface. Therefore, results can be estracted and manipulated using custom python-scripts, allowing the end-user to produce custom information.

Finally, STKO uses an efficient opensource third-party database library for storing results, the HDF5 database library. The MPCORecorder is a new recorder class for OpenSees that allows OpenSees to write results data in the format required by STKO.

All these features in one Software: STKO, a revolutionary visualization toolkit for Opensees


Save/Load existing post-processor files (restore plots, charts, etc.)

Import of one or multiple MPCO output databases


Deformed shape

Surface color map

Volume color map

Gauss-point plot

Beam/Shell fiber-section plot

Vector plot

Iso-surface plot



Extract data from database:

Extract data from nodes

Extract data from gauss points

Extract data from fibers

Create 2D Charts


Python scripting interface

Add new user-defined components for pre-processing

Extend STKO built-in interfaces for OpenSees components

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