DANSK DSF/ISO/FDIS 7626-5 PDF

This part of ISO 7626 specifies procedures for measuring mechanical mobility and other frequencyresponse functions of structures excited by means of an impulsive force generated by an exciter which is not attached to the structure under test. It is applicable to the measurement of mobility, accelerance or dynamic compliance, either as a driving point measurement or as a transfer measurement, using impact excitation. Other excitation methods, such as step relaxation and transient random, lead to signal-processing requirements similar to those of impact data. However, such methods are outside the scope of this part of ISO 7626 because they involve the use of an exciter which is attached to the structure. The signal analysis methods covered are all based on the discrete Fourier transform (DFT), which is performed mostly by a Fast Fourier Transformation (FFT) algorithm. This restriction in scope is based solely on the wide availability of equipment which implements these methods and on the large base of experience in using these methods. It is not intended to exclude the use of other methods currently under development.