Modal testing

The basic theory of modal analysis is developed in order to evaluate the consequences of using different test procedures. Piezoelectric accelerometer and force transducer characteristics are reviewed in order to show their basic electrical and mechanical response characteristics. Unique force and accelerometer behaviours are reviewed as sources of unwanted signal contamination. The consequences of having 36 input/output frequency–response function relationships between any two points in a structure are reviewed in terms of finite–element program model validation, structural modification, and the combining of two substructures.