STKO | Scientific ToolKit for OpenSees |

Scientific ToolKit for OpenSees

STKO (Scientific ToolKit for OpenSees) is an extended version of MPC, specialized to interact with OpenSees: STKO inherits all the capabilities of MPC in modeling, meshing, data preparation and visualization. It also contains extension modules to translate MPC models into input files for the OpenSees solver and to visualize analysis results with all the capabilities which MPC offers.



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 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.


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). Courtesy of Jenny Ramirez Calderon – PhD thesis

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.

STKO & Analysis


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

Curve modeling

Surface modeling

Solid modeling

Interface modeling

STKO & Analysis



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

STKO & Analysis



Uniaxial | nD



Beam fiber-section

Shell layered-section

STKO & Analysis


SP constraints

MP constraints


Uniform exitation pattern

Multi-support exitation pattern

STKO & Analysis






… 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 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

STKO & Analysis


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

Import of one or multiple MPCO output databases

STKO & Analysis


Deformed shape

Surface color map

Volume color map

Gauss-point plot

Beam/Shell fiber-section plot

Vector plot

Iso-surface plot


STKO & Analysis


Extract chart data from database:

From nodes

From gauss points

From fibers

2D Charts

STKO & Analysis


Python scripting interface

STKO provides the HDF5 database library on standard and advanced visualization techniques in post-processing and the structure of the proposed file format.

It most of all includes Python-based scripting interface for manipulation and customization of results and the implementation of the new recorder class in OpenSees. STKO shows numerical applications. It also provides examples of soil-structure interactions, visualization of beam and shell data defined at gauss and at sub-integration points. Moreover the management of output database via user-defined scripts, extrapolation and manipulation of data for production of new custom results.