About base excitation

- July 11, 2025 at 7:49 am
  
  22ek075
  Subscriber
  
  I am currently working on a “Transient Structural Analysis”
  . I am trying to reproduce a vibration experiment in my analysis. Therefore, I would like to use “base excitation” when inputting acceleration. However, when I select “YES” for base excitation, I cannot select the geometry in the boundary conditions. How can I select the surface of the base as a boundary condition?
- July 11, 2025 at 8:56 pm
  
  peteroznewman
  Subscriber
  
  See if you find something helpful in this discussion: https://innovationspace.ansys.com/forum/forums/topic/base-excitation-absolute-result/
  Base excitation is available when you are doing a Modal Superpostion type of Transient Structural and the supports must be Fixed or Remote Displacement with six zero values.
- July 15, 2025 at 7:57 am
  
  Akshay Singh
  Ansys Employee
  
  Hello, For appling base exctation load, you can only select the predefined boundary condition(fixed support/displacement etc…) available from the upstream Modal analysis using a drop down menu.
  It cannot be scoped manually to a surface using geometry selection.
  So if the said face is already a support in Modal analysis(MSUP) for instance, it can be chosen a base excitation for acceleration using dropdown options.Refer the following help doc for more details: 17.6.1.1. Acceleration