STEM

STEM is an open-source calculation model that is developed to compute the impact of mitigation techniques on railway induced vibrations.

In STEM the train-track interaction and the propagation of the vibrations through the subsurface are simulated. The model is able to compute the vibration levels at the ground surface taking into account the presence of irregularities in the track geometry, the type of train and train speed, and the spatial variability of the track and soil properties.

Scope of the STEM model

The STEM model is based on the finite element method and it is powered by Kratos Multiphysics.

User guide

Background information

STEM is a numerical model based on the finite element method. It is recommended to have a basic understanding of the finite element theory before using STEM.

STEM is build in Python. It is recommended to have a basic understanding of Python before using STEM. For new users of Python, the following resources are recommended:

• Python beginners guide

Alternatively, you can follow one of the many online free courses, for example (the STEM team is not affiliated to any of these courses):

• Introduction to Python

• Programming for Everybody

To use STEM it is convenient to use an IDE (Integrated Development Environment) for Python. The STEM team recommends to use PyCharm or Visual Studio Code. More information can be found in the following links:

• VS Code in Python

• PyCharm in Python

To visualise the results STEM makes use of ParaView. It is recommended to have a basic understanding of ParaView before using STEM. The following resources are recommended:

• ParaView tutorials

STEM Installation

To install STEM you need to install the following items:

• STEM Python package

• ParaView

Optionally, you can install gmsh to visualise the mesh.

Tutorials

• Stationary load on a 3D field

• Moving load on an embankment in 3D

• Train model (UVEC) on track and embankment in 3D

STEM interface definitions

STEM has interface definitions to interact with the model, and allow the extension of the model and the use of different train and material models:

• User-defined vehicle model

• User-defined soil models

How to contribute

If you want contribute to STEM please follow the steps defined in Code contribution.

STEM team

STEM is a research programme that results from a collaboration between the following partners:

• ProRail

• Deltares

• TNO

• TU Delft

The STEM team.

Package documentation

The stem package documentation.