Finite Element Analysis with Abaqus: Part 1 - Cantilever Beam Stress Analysis

Finite element analysis (FEA) is a broader topic, and there are tons of materials available online to learn this method. In this tutorial, I am not going to explain the FEA, rather I will show you how to use a software, such as ABAQUS that uses this technique. This is a quick tutorial for the beginners to help simulate a simple model for the very first time. I am using Abaqus 2019 to present this tutorial. The problem is very simple and straightforward. We see below, a cantilever beam, which has one fixed end, and the other end experiences a concentrated load of magnitude 200000N. We are interested to see the stress distribution along the cantilever beam due to the concentrated load.

A cantilever beam with a concentrated load at one end

To begin, at first, you need to open Abaqus CAE, which looks like the following. Here, we will design our geometry, apply boundary conditions, and simulate the results.

Step-1: The first step is to define a part for the geometry. As shown below, double click on on the part icon from the left side model tree. For this simple simulation, we are considering the part as a 2D planar, deformable and shell type. You also see that the approximate size 200 is depicted in the dialog box. This refers to the dimension of the working window. Since, Abaqus does not follow any specific units, so you have to be consistent while putting your own dimensions.

When you are done with providing those information, your display will look like the following, where you will be ready to draw your geometry.

Our geometry is a rectangular bar, so simply pick the rectangle from the left side toolbar and provide the dimensions. In this case, the length of the bar is 10 m and height is 5 m. So, we simply provide 10 unit as length and 5 unit as height as if they are all in SI units.

When you are done with creating your geometry, it will look like following:

Step-2: The next step is to select material properties of the beam. As shown below, click on the dropdown menu, and select property.

Choose the material icon from the left side menu. If you like, you can name your material.

Our material property should be under mechanical and it is elastic.

Then, put the values of the Young's modulus and Poisson's ratio as shown below.

Step-3: The next step is to create a section for the geometry that you just designed, and then, assign it for Abaqus analysis. It is required to let Abaqus know that which section of the geometry will be required for analysis. Otherwise, it won't let users run the simulation.

When you click on the create section icon, it will be opted for further information. Choose solid homogeneous material and plain stress/strain ratio is set to 1.

Then, select the entire geometry above as our region for the analysis which should look like the following screenshot after selection.

Step-4: In this step, we need to select step from the dropdown menu as shown below. Here, we will define the boundary conditions and applied loads on the geometry.

Double on the Step icon from the left side model tree. It will pop-up following window. Select the analysis as Static and General. Click Continue.

The following window will appear, where we select the nonlinearity off. Then, hit Ok.

Next, we will apply a concentrated load at the end of the beam. From the dropdown menu shown below, click on Load.

You will see the following window. The load for this problem is concentrated force. Click on that. Then select the point where the load needs to be applied. In our case, it is at the top end of the beam.

So, the load is applied, which is seen below.

Now, we are ready to apply boundary condition. As seen below, click on the icon from the left menu, and it will pop-up the following window.

For this problem, one end of the beam is fixed, and other end is free and experiencing a load. So, to fix one end, select Displacement/Rotation boundary condition and choose all parameters 0 to fix it. U1, U2 refer to the displacement along X and Y axes respectively. UR3 is the rotation about Z axis that is perpendicular to the plane.

After applying the boundary condition, it will look like the following.

Step-5: In this step, we will create mesh to solve the problem. Meshing is very important part for any FE simulation. First, click on Assign Mesh Control icon, then, select Structured and hit OK.

Then, click on Seeds. It controls the number of meshes in your geometry. Select the following value for our problem. Then, hit on Mesh icon from the left menu to generate the mesh.

Step-6: This is the final step. In this step, we need to submit to Abaqus solvers what we have done so far. As seen below, from the dropdown menu, select Job and double click on its icon to create. Then, hit Continue.

The following window will pop-up. Just select all default parameters and move on.

Next, right click on the Job icon and hit Submit. Now, Abaqus will analyze the problem.

Now, if you like to see the results, you need to open a file from the Abaqus working directory. The file extension is .odb, and in our case, it is Job-1.odb. Select the file and hit OK.

Now, click on the Contour plot and it will look like the following - the stress distribution along the beam due to the applied load. We are done for now!