Modal Pretest Analysis

When a finite element model of a structure is available, then pretest analysis is about using this model to simulate and optimize tests.

Modal pretest analysis provides test engineers with optimal locations and directions to excite the structure, and to position measurement transducers.  Modal  correlation analysis and finite element model updating considerably benefit from tests that were made using carefully selected sensor locations.

Some questions that can be answered by modal pretest analysis are:

  • Find optimal exciter and transducer locations for modal testing

  • Create a test model from a reduced finite element model and export in a format readable by modal test packages.

  • Determine the directions normal to the surface of curved surfaces from the finite element model and use this information for transforming modal test results in Cartesian coordinates.

  • Assess the influence of the accelerometer mass on the model parameters.

  • How many modes can be expected in a given frequency range.