How To Perform Prestressed Modal Analysis — Lesson 2

A modal analysis determines the vibration characteristics such as natural frequencies and mode shapes of a structure; it serves as a starting point for several linear dynamic analyses. The mode frequencies and shapes depend on the distribution of mass and stiffness in the structure. In a stressed state the stiffness changes due to the stress stiffening, altering its vibration characteristics. In this video, you will see how to perform a prestressed modal analysis in Ansys Workbench. Additionally, you will see how different natures of stress (tension and compression) change the frequency.

Alternate video link.

Video Highlights

0:49 - Presence of Stress altering the Vibration Characteristics

1:16 - Examples of the Prestress affecting the Modal Frequencies

1:43 - What is a Pre-Stressed Modal Analysis?

1:51 - Governing Equations associated with Modal and Pre-Stressed Modal Analysis

2:30 - Workflow to Perform a Pre-Stressed Modal Analysis

3:18 - Few points about Pre-Stressed Modal Analyses

Simulation Files

Download the accompanying geometry and archived files here. The student version of Ansys Simulation Software can be downloaded here.