Beginners guide to doing (1) Base Shake analysis and (2) Multi-input analysis within the Frequency Domain

Presented by: Dr. Neil WM Bishop, CEO, CAEfatigue Limited


Frequency domain methods for fatigue analysis and/or for general random response analysis have experienced a resurgence over the last few years due to improved technology and better computational processes. Today, a complete range of models can be processed from full vehicle systems to local component systems. Single input BASE shake loads and multiple correlated input loads can now be easily processed by the User. These loading conditions can also contain random PSDs and/or deterministic components like a sine sweep.  Different kinds of fatigue life calculations can be done including both Stress-Life and Strain-Life approaches.

Webinar Outline

Most of the common dynamic solvers are widely used for this kind of analysis. However, most analysts still struggle to decide the fundamental analysis procedures. Questions which are raised include:

  • How to correctly define boundary conditions
  • How to set up clustering (distribution) of frequencies around modes
  • The minimum frequency and maximum frequencies to use
  • The range of modes to be requested, whether a Modal or Direct method should be used
  • How to set up a Base Shake or Multi-input fatigue analysis 
  • And many other issues

During the webinar, these questions will be addressed, discussed, and recommendations made about what settings should be used.

Who Should Attend?

Users / Managers who would like to understand both the technical advantages and business advantages of using frequency domain technology to calculate fatigue and random response.


Log of Damage fringe plot for an exhaust pipe and truck cab (plotted using CFG tool).



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