Getting Started

Introduction

abqpy is a Python package providing type hints for Python scripting of Abaqus, you can use it to write you Python script of Abaqus fluently, even without doing anything in Abaqus. It also provides some simple APIs to execute the Abaqus commands so that you can run your Python script to build the model, submit the job and extract the output data in just one Python script, even without opening the Abaqus/CAE.

Two Python interpreters

Before we go any further, it is necessary for us to understand two Python interpreters.

When we use the Abaqus/CAE graphical user interface (GUI) to create a model and to visualize the results, commands are issued internally by Abaqus/CAE after every operation. These commands reflect the geometry you created along with the options and settings you selected from each dialog box. The GUI generates commands in an object-oriented programming language called Python. The commands issued by the GUI are sent to the Abaqus/CAE kernel. The kernel interprets the commands and uses the options and settings to create an internal representation of our model. The kernel is the brains behind Abaqus/CAE. The GUI is the interface between the user and the kernel.

In a word, Abaqus use Python language to interact with the Abaqus kernel, everything that can be done in Abaqus/CAE, can also be done using Python script. Abaqus has already installed a Python interpreter so that Abaqus/CAE can use it to interact with the Abaqus kernel.

For some reasons, we cannot directly use the Python interpreter inside Abaqus to build an Abaqus model. But fortunately, we can use the commands provided by Abaqus to access it. i.e.

abaqus cae
    [database=database-file]
    [replay=replay-file]
    [recover=journal-file]
    [startup=startup-file]
    [script=script-file]
    [noGUI=noGUI-file]
    [noenvstartup]
    [noSavedOptions]
    [noSavedGuiPrefs]
    [noStartupDialog]
    [custom=script-file]
    [guiTester=GUI-script]
    [guiRecord]
    [guiNoRecord]

Usually, we can use the noGUI-file or script-file to execute our Python script in Abaqus.

Another Python interpreter, is the Python interpreter installed by ourselves, where abqpy is installed. abqpy provides a bridge to connect our Python script to Abaqus Python interpreter, it provides type hints for Python scripting for Abaqus, enabling us to write a Abaqus Python script quickly.

How does this package work?

abqpy is just a package to provide type hints for Abaqus/Python scripting, it is installed outside Abaqus/Python environment, you can use abqpy to write your Abaqus/Python scripts, and run the scripts inside Abaqus on your own. However, with the help of Abaqus command, an easier way can be achieved: you can actually run the script using your own Python interpreter without opening Abaqus, which is achieved via the abaqus command like this:

abaqus cae noGUI=script.py

The secret is hided in the run() function:

def run():
    abaqus = 'abaqus'
    if 'ABAQUS_BAT_PATH' in os.environ.keys():
        abaqus = os.environ['ABAQUS_BAT_PATH']

    filePath = os.path.abspath(__main__.__file__)
    args = " ".join(sys.argv[1:])

    os.system(f"{abaqus} cae noGUI={filePath} -- {args}")

    sys.exit(0)

In this package, the abaqus module is reimplemented to automatically call this function. If you import this module in the top of your script (i.e., from abaqus import *), your Python interpreter (not Abaqus Python interpreter) will call this function and use the abaqus command to submit the script to Abaqus. After it is submitted to Abaqus, run() will exit the interpreter, because the script will already run in Abaqus Python interpreter.

In the output script, we might not want to always use the abaqus module, which needs the Abaqus/CAE kernel (and its license), but instead the module odbAccess (i.e., from odbAccess import *), which requires only the Abaqus Python interpreter. Then another similar abaqus command line is needed:

abaqus python script.py

So, odbAccess is also reimplemented to call the run() function, and the actual implementation of this function is similar to:

def run(cae = True):
    abaqus = 'abaqus'
    if 'ABAQUS_BAT_PATH' in os.environ.keys():
        abaqus = os.environ['ABAQUS_BAT_PATH']

    filePath = os.path.abspath(__main__.__file__)
    args = " ".join(sys.argv[1:])

    if cae:
        os.system(f"{abaqus} cae noGUI={filePath} -- {args}")
    else:
        os.system(f"{abaqus} python {filePath} {args}")
    sys.exit(0)

In summary: this function will be called when you import one of the two modules (abaqus or odbAccess). It will pass the argument cae = True in abaqus module and cae = False in odbAccess module. Therefore, if you want to run your Python script in Abaqus Python environment, please make sure to import one of these modules on the top of your script.

Installation

abqpy supports Python 3.7 or a later version. If you are using Python 3.6 or an earlier version, please upgrade to Python 3.7 or a later version.

abqpy is uploaded to PyPI, you can simply install it using pip:

pip install abqpy

abqpy is also uploaded to anaconda, you can use conda to install it:

conda install -c haiiliin abqpy

You may install the latest development version by cloning the GitHub repository and use python to install from the local directory:

git clone https://github.com/haiiliin/abqpy.git
cd abqpy
pip install -r requirements.txt
python setup.py install

Optional Requirements

If you want to use the Jupyter notebook to write your Abaqus/Python scripts, you need to install ipynbname:

pip install ipynbname

Install A Specific Version

You can specify the version number when installing abqpy, for example:

Using pip:

pip install abqpy==2022.3.4

Using conda:

conda install -c haiiliin abqpy=2022.3.4

A better way is to use * to match specific version:

pip install abqpy==2022.*

Abaqus command

In order to use Abaqus command to execute the Python script and submit the job, you need to tell abqpy where the Abaqus command located. Usually, Abaqus command locates in a directory like this:

C:/SIMULIA/Commands/abaqus.bat

You can add the directory C:/SIMULIA/Commands to the system environment variable Path, or you can create a new system variable named ABAQUS_BAT_PATH, and set the value to the file path of the Abaqus command, i.e., C:/SIMULIA/Commands/abaqus.bat.