An Example for Dload Subroutine

Description

Before talking about the Dload subroutine code, we need to know what the subroutine code is but let’s start with Abaqus:

Abaqus:

Abaqus is an FEA software to analyze models with high complexity. The provided option by this software creates a great environment to study various models. Not even solid mechanics but also thermal and fluid mechanic models can be simulated in this software. It worth to mention the fluid mechanic model was separated after Abaqus 6.16 and since version 2017 the company strat to develop an independent solver for it. In order to increase the complexity of models, engineers can use FORTRAN to develop subroutine code and Python to create a model by scripting. Here we provide a simple description to explain how these two features help you to develop a model.

Scripting by Python:

Imagine you want to create a part with holes randomly distributed inside it. You need to bring a calculator and a piece of paper to find some random number to find the center and radius of those holes. The other option is to use Matlab code or any other coding languages to find those random values. However, after finding those values you still need to create those holes inside your models. You need to modify your part at least one time per each hole. Fortunately, Abauqs provided Python scripting to avoid it. You can easily create your code there and use the provided function to create and modify those holes inside your part. Consequently, you don’t need to do it by clicking and modifying your part. You can develop a code in Python to does the job for you.

Subroutine for Abaqus:

Now, you created your complex part and now you are ready to define your material properties, boundary condition and loads. Now, you notice your material properties are very complex and it changes by time. Even if you didn’t have this problem, you also need to change the value of time-dependent on material properties. You look at the Abaqus feature and think there is no way you can do it. In fact, your model should change during the process. Your values are not just a simple number and you need to make them as a function of time and other variables. Here is the time you need to use subroutine to define those complex properties in your model. You need to use the proper function known as Subroutine and define your function there and run that by your model.

More details about this product:

If someone claims s/he knows subroutine, it means there is someone who knows all the Matlab features. Every subroutine has a special feature that makes it different from the other codes. However, it doesn’t mean if you don’t know one subroutine you need to start as a beginner. You just need to use the same algorithm from the other subroutine then you become familiar with the code.

Dload:

Dload code is one of the most simple subroutine code you can start to learn. it is a subroutine in the Abaqus static general step module. You can define complex mechanical loads for your model with minimum effort. The usage of Dload is similar to Dflux and most of the variables are the same.

An example of the Dload subroutine in Abaqus is provided. Here, a constant circular shape load is applied on a plane. The plane is fixed from the edges and because of the load you can see it bend from the middle section. In addition, in the PowerPoint file, you can find good information about the subroutine code. If you think you need more background it might be a good idea to see the other video about the subroutine (Please click here).

Using the Dload subroutine allows you to apply load with different distribution which can be dependent on the geometry of part and time as well. To use subroutine we need to use FORTRAN code and also Abaqus needs to be linked to Intel FORTRAN. The video is short so you can learn this in less than 15 minutes and you will have the output and Abaqus CAE file.

 In this video, we avoid giving too many details so you can easily use these products. In here you can find the following files:

Abaqus files: CAE, ODB, INP, FORTRAN, and JNL

Powerpoint files that contain more details.

Video files: How to create this model, Powerpoint presentation.

For more information please send me an Email:

rezatangestani@hyperlyceum.com