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.

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.

Install with pip

abqpy can be installed via pip from PyPI.

pip install abqpy

Install from source

You can also install abqpy from source:

pip install git+https://github.com/haiiliin/abqpy@2023

Install a specific version

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

pip install abqpy==2023.4.3
pip install abqpy==2023.*

Optional dependencies

If you want to use the Jupyter notebook to write your Abaqus/Python scripts, use the following command:

pip install abqpy[jupyter]

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, because it needs the Abaqus/CAE kernel (and its license). Instead, we use 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, the odbAccess module 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.

Write your Abaqus/Python script

After installing the abqpy package, you can start writing your own Abaqus/Python script to build your model. You can refer abqpy/examples at main · haiiliin/abqpy for some tests of the script, for more detailed documentation, please check abqpy documentation.

Setup your Abaqus Environment

In order to use Abaqus command to execute the Python script and submit the job, you need to tell abqpy where the Abaqus command is 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.

Run your Abaqus/Python script

Now you can just run your Abaqus/Python script using your own Python interpreter that abqpy is installed.

  • Create an Abaqus Model

    Create an Abaqus Model

  • Extract Output Data

    Extract Output Data

What next?

You may wonder how does this package work, you can go Getting Started for more detailed introduction and go Tutorials for a simple tutorial. For more documentation about Abaqus/Python scripting, please check API References for more detailed API references.