Tutorial: Linear Static Analysis of a Crane

This article provides a step-by-step tutorial for a linear static analysis of a crane.

This tutorial teaches how to:

• Set up and run a linear static analysis of a crane.
• Assign boundary conditions, material and other properties to the simulation.
• Mesh with the SimScale standard meshing algorithm.

We are following the typical SimScale workflow:

1. Preparing the CAD model for the simulation.
2. Setting up the simulation.
3. Creating the mesh.
4. Run the simulation and analyze the results.

1. Prepare the CAD Model and Select the Analysis Type

Firstly, click the button below. It will copy the tutorial project containing the geometry into your own workbench.

After that, the empty project will be imported into your profile. The following picture demonstrates what should be visible after importing the tutorial project.

1.1 Create the Simulation

Firstly, you can create a new simulation by clicking the ‘Create Simulation’ button in the geometry dialog box.

Secondly, after clicking the button the simulation library will pop up:

We will select the ‘Static’ analysis type for this simulation.

After selecting the analysis type, the simulation tree will appear. This shows you the settings that we will need to define before starting the simulation.

Now, you are ready to setup the linear static analysis of the crane.

2. Simulation Settings

Before running the simulation, we will need to define important settings. These settings are:

• Direction of gravity
• Materials of the crane
• Boundary conditions

2.1 Direction of Gravity

The magnitude and direction of gravity highly affect the result of the simulation, because the crane’s own weight is a noticeable load already. You can define the magnitude and direction of gravity by clicking the ‘Model’ in your simulation tree.

The magnitude of gravity is 9.81 \(m/s^2\) and the direction of gravity for this simulation will be in the negative y-direction.

2.2 Define a Material

You will also need to define the material of your crane. You can choose the material of your crane by clicking ‘Materials’ in the simulation tree which opens the SimScale material library.:

• For this simulation please select ‘Steel’ and confirm with ‘Apply’.

• You have successfully created a new material. Now you need to assign it to a geometry, so simply click on the crane to assign it.
• You can also define your own material by changing the material property. Additionally, you can give it a new name.

2.3 Assign the Boundary Conditions

Boundary conditions play a key role in simulations. They define the physical conditions, which you want to analyze your design with. In this simulation, we will apply a fixed support-, and a force boundary condition. The places where the boundary conditions are applied can be seen below:

The next steps will show you how to assign each boundary conditions.

a. Fixed Suppot

Firstly, you can define a boundary condition by going to ‘Boundary conditions’ in your simulation tree and this will show you the list of possible boundary conditions that can be applied for a static linear simulation. This is the step where you select ‘Fixed support’ as a boundary condition.

After that, a dialog box of the fixed support boundary condition will show up. Here, you will only need to define where the support of the crane is located.

b. Force

You can follow the similar steps as before to select the Force boundary conditions.

We will define our force to be -500 kN in the y-direction. Since the force is a downward force, it is negative.

3. Mesh

To get the mesh, we recommend using the standard algorithm, which is automated and delivers good results for the most geometries.

The only change you need to do here is enabling 2nd order elements so that you will gain more accurate results.

The resulting mesh looks like this:

4. Start the Simulation

You can start a simulation run by going to ‘Simulation run’ in the simulation tree.

After clicking, you will be shown a dialog box that shows you an estimate of the computing resource that will be spent to run your simulation. Moreover, you are also allowed to change the name of your simulation run, this can be used to differentiate each run.

You can start the simulation run by pressing the ‘Start’ button.

5. Post-Processing

After the simulation run has finished computing, you can access the results by one of two methods:

1. Click the ‘Solution fields’ under the simulation run.
2. Click the ‘Post-process results’ button in the run dialog.

When you have been directed in the post-processor, you can start analyzing your results. For this tutorial, we will show the von Mises stress and the deformation of the crane.

5.1 Von Mises Stress

You can show the von Mises stress of the crane by going to the Parts Color section in the Filters panel, and selecting ‘Von Mises Stress’ for Coloring. It could be selected by default:

After that, the von Mises stress in the crane is visualized:

It can be seen that the highest stress levels occur at the supported end of the structure. It is clear from the legend which members are under high loading and which members are under low loading, being colored yellow and blue respectively.

5.2 Displacement

Since deformation is also important in stress analysis, we can visualize both the von Mises stress and displacement at the same time:

1. Click the ‘Add Filter’ button in the Filters panel at the top left.
2. Select ‘Displacement’ from the drop-down list.

Since the displacement of the crane is very small, we will need to scale the displacement to clearly visualize it. You can scale the displacement by going to the newly created Displacement section of the Filters panel. Here, you can change the Scaling factor of the deformation:

For example, the picture below shows a visualization of the von Mises stress and the deformed crane with a scaling factor of 50:

In this last plot, the deformation shape of the crane can be visualized. The effect of the fixed constraints and the end load and gravity can be appreciated. Notice the downward displacement and slight rotation of the end block on the right-hand-side, which could be an important factor in the design process.

Congratulations! You finished the tutorial!

Last updated: February 11th, 2021

What's Next

Tutorial about the Bending of an Aluminium Pipe