Structural Dynamics Software

Type 8420-A (Replaces Type 8721)  BK Connect Advanced Modal Analysis

Type 8420-A (Replaces Type 8721) BK Connect Advanced Modal Analysis

This BK Connect application adds to BK Connect Modal Analysis Type 8420. It enhances your structural dynamics capabilities by adding polyreference analysis of multi-shaker measurements, or impact hammer measurements using triaxial or multiple single-axis accelerometers as references. It adds best-in-class mode indicator functions (MIFs), curve-fitters and validation tools to ensure accurate results even in the most demanding situations, such as analyzing structures with heavily damped, complex and coupled modes.


  • Polyreference classical modal analysis from measured frequency response functions (FRFs) when, for example, decoupling closely coupled modes
  • Estimation of modal parameters to be used for finite element (FE) model correlation and updating, design verification, trouble-shooting, benchmarking and quality control
  • Test planning and validation using finite element analysis (FEA) results

This application is usually paired with BK Connect Structural Measurements – Hammer and Shaker Type 8411 and/or BK Connect Advanced Sine Measurements Type 8412 for test set-up, measurement and measurement validation using the same intuitive, geometry-guided GUI.


With BK Connect Advanced Modal Analysis, you get the best possible tools for planning a modal test and analyzing the results. Powerful test-planning tools such as the geometry node selection tool for decimating a finite element model down to a test geometry are included, as well as a selected set of best-in-class MIFs, curve-fitters and validation tools, ensuring you always have the right tools at hand even in the most demanding situations.


This software adds advanced functions to BK Connect Modal Analysis Type 8420:

  • Geometry node selection task for decimating a FE models down to a test geometry
  • As an open, stand-alone application with your existing data acquisition system
  • MIFs: Complex MIF (CMIF) and Multi-variate MIF (MMIF)
  • Curve-fitting:
    • MDOF Curve-fitters: Polyreference Time and Polyreference Frequency (no reference limitations), Rational Fraction Polynomial-Z (RFP-Z), Eigensystem
    • Realization and Alias-Free Polyreference (AFPoly™)
    • Local solve curve-fitting (RFP-Z) Stability diagram with Enhanced Mode Solution (RFP-Z)


  • Add geometry-guided hammer and shaker measurements and stepped sine measurements –  BK Connect Structural Measurements Type 8411 and BK Connect Advanced Sine Measurements Type 8412, respectively
  • Import Nastran, Ansys and Abaqus finite element models for test planning and validation – BK Connect Finite Element Interfaces Types 8400-D/E/F
  • Model correlation between test and finite element models – BK Connect Correlation Analysis Type 8421


  • BK Connect Data Viewer Type 8400
  • BK Connect Geometry Type 8410
  • BK Connect Modal Analysis Type 8420