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PyRolL is an OpenSource rolling framework, aimed to provide a fast and extensible base for rolling simulation. The current focus lies on groove rolling in elongation grooves. The core packages comes with a basic set of models to allow a first estimation of forces and torques occurring in a pass sequence. There is a flexible plugin system, able to modify and extend the model set available to describe the process.


The PyRolL Core package is installable via PyPI

pip install pyroll

A collection of plugin packages can be installed the same way, the packages names usually start with pyroll-. Use the PyPI search or look at the projects GitHub page for discovering plugins.

Basic Usage

The package provides a simple CLI tool that can be used to load input data, run the solution procedure and export the solution data. The CLI provides several commands that can and must be chained in one call. No state is preserved between different program runs.

The simplest use case is to read from a python script, solve and render the results to an HTML report page. The default input file is, the default report file report.html.

pyroll input-py solve report

One may specify the files explicitly with the -f/--file option:

pyroll input-py -f solve report -f other_report.html

A most basic input file may look like:

from pyroll.core import Profile, RollPass, Transport, Roll, DiamondGroove, SquareGroove

in_profile = Profile.square(
    side=45e-3, corner_radius=3e-3,
    temperature=1200 + 273.15, flow_stress=100e6, strain=0,

sequence = [
        label="Diamond I", velocity=1, gap=3e-3,
                usable_width=76.5e-3, tip_depth=22e-3, r1=12e-3, r2=8e-3
        label="Square II", velocity=1, gap=3e-3,
                usable_width=52.7e-3, tip_depth=26e-3, r1=8e-3, r2=6e-3

The file must define the variables in_profile and sequence defining the state of the initial workpiece and the sequence of roll passes and transport ranges. For a more advanced example, representing a pass sequence at the 3-high mill at the Institute of Metals Forming, run:

pyroll create-input-py -k trio -f

The PyRolL command line interface resides additionally on a YAML configuration file config.yaml. The default file can be created using the following command:

pyroll create-config

The core section of this file is the plugins section. Here one can specify a list of plugins that will be loaded in each simulation run. Another way of loading plugins is to directly import them in the input Python script.

It is recommended to create a fresh directory for each simulation project to avoid the need to specify the filenames explicitly. A basic input and config file can be created in the current directory using

pyroll new