{"id":32837,"date":"2020-09-11T15:41:07","date_gmt":"2020-09-11T15:41:07","guid":{"rendered":"https:\/\/www.simscale.com\/?page_id=32837"},"modified":"2025-07-17T17:29:57","modified_gmt":"2025-07-17T17:29:57","slug":"frequency-analysis","status":"publish","type":"page","link":"https:\/\/www.simscale.com\/docs\/analysis-types\/frequency-analysis\/","title":{"rendered":"Frequency Analysis"},"content":{"rendered":"\n

The Frequency Analysis simulation type allows the computation of natural (under no external load excitation) frequencies of oscillation of a structure and the corresponding oscillation mode shapes. The resulting frequencies and deformation modes are dependent on the geometry and material distribution of the structure, with or without the displacement constraints. In SimScale, the Code Aster<\/a> solver is used to perform the frequency analysis.<\/p>\n\n\n\n

The results from a frequency analysis enable you to evaluate the overall rigidity of your structure, as well as the rigidity of local regions. The lower frequencies of oscillation can be used as input for the seismic or wind load assessment and computation of structures. Also, in parts and structures subjected to variable frequency loads, the fundamental frequencies are used to avoid resonance between the natural oscillation modes and the applied load.<\/p>\n\n\n

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\"example<\/a>
Figure 1: Natural vibration mode shape of a quarter ring<\/figcaption><\/figure>\n<\/div>\n\n\n

Creating a Frequency Analysis<\/h2>\n\n\n\n

To create a frequency analysis, first select the desired geometry from the top of the simulation tree on the left, and then click on ‘Create Simulation<\/strong>‘:<\/p>\n\n\n

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\"creating<\/a>
Figure 2: Create simulation for the selected geometry<\/figcaption><\/figure>\n<\/div>\n\n\n

The simulation library window will appear with all the available analysis types:<\/p>\n\n\n\n

\"simulation<\/a>
Figure 3: SimScale simulation library. Select Frequency Analysis<\/em> and click on ‘Create Simulation<\/strong>‘.<\/figcaption><\/figure>\n\n\n\n

Select ‘Frequency Analysis’<\/strong> from the list and confirm the choice by clicking on the ‘Create Simulation<\/strong>‘ button. A new element will appear in the simulation tree with all the available settings:<\/p>\n\n\n

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\"simulation<\/a>
Figure 4: Frequency analysis simulation tree.<\/figcaption><\/figure>\n<\/div>\n\n\n

In the next sections, the different simulations settings that need to be defined to run the simulation are described:<\/p>\n\n\n\n

Global Settings<\/h2>\n\n\n\n

The global settings are accessed by clicking on the simulation name, in this case, ‘Frequency Analysis’<\/em>, from the simulation tree. For this type of analysis, there are no further parameters to change. For more information, please refer to the global settings<\/a> page.<\/p>\n\n\n\n

Geometry<\/h2>\n\n\n\n

The geometry panel contains the CAD model used for the simulation. Details of CAD handling and manipulation are described in the pre-processing<\/a> page. Additionally, if you are facing problems with CAD complexities and uploading then it is advised to visit this documentation<\/a>.<\/p>\n\n\n\n

Contacts<\/h2>\n\n\n\n

Geometrical models consisting of multiple bodies require connections to be defined on faces that make contact. The possible choices are:<\/p>\n\n\n\n