AFPoly

AFPoly™ stands for “Alias Free Polyreference” and refers to a multi-reference modal parameter estimation technique that has been recently developed. AFPoly is a frequency domain Laplace method that 1) uses orthogonal polynomials, and 2) accounts for out-of-band poles when solving for modal parameters.

The AFPoly GUI uses this recently developed technique to solve for modal parameters (shape coefficients, damping, and natural frequency) in a step-by-step manner. After importing ideas_fn frequency response functions (FRF) into the GUI, the user will solve for roots. A stability diagram helps the user select the valid roots. Shapes are then extracted and verified by overlaying various test and synthesized mode indicator functions. Once the shapes have been verified, they can be exported.

Benefits of AFPoly?

Some of the many benefits to using AFPoly are:

• Increased accuracy in parameter estimation due to removal of aliasing that effects other curve fitters.
• Ability to fit lightly damped modes and highly damped modes across a large frequency range in a single pass.
  
• Fast, efficient solver
  • AFPoly utilizes parallel processing on your dual-processor machine for faster solution times.
• Simple, straight-forward GUI that is easy to learn and easy to use.
  

Where Can I Get AFPoly?

The AFPoly curve fitter is now available in I-deas Test software from B&K, ME'scope (version 5.0 released on June 2007) from Vibrant Technology, and available in the IMAT+Testkit package (version 2.2 released on April 25, 2007) from ATA Engineering.

If you have any questions about the process, please email us.

More AFPoly Information

• AFPoly brochure
• AFPoly technical paper presented at IMAC XXV
  
• AFPoly Documentation
• AFPoly Example Problem (with data you can download and practice with)

AFPoly was developed with Microsoft .NET 2.0.

If you have any questions about AFPoly please contact us here.

Last updated: October 2007