BS 6897-5:1995
Experimental determination of mechanical mobility - Measurement using impact excitation with an exciter which is not attached to the structure

Standard No.

BS 6897-5:1995

Release Date

1995

Published By

British Standards Institution (BSI)

Latest

BS 6897-5:1995

Replace

91/70504 DC-1991

Scope

This part of ISO 7626 specifies procedures for meas-uring mechanical mobility and other frequency-response functions of structures excited by means of a translational 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 struc-ture. The signal analysis methods covered are all based on the discrete Fourier transform. 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. Impact excitation is also widely used to obtain uncali-brated frequency-response information. For example, a quick impact test which obtains approximate natural frequencies and mode shapes can be quite helpful in planning a random or sinusoidal test for accurate mo-bility measurements. However, these uses of impact excitation to obtain qualitative results should not be confused with its use for mobility measurements. This part of ISO 7626 is limited to the use of impact excitation techniques for making accurate mobility measurements.

BS 6897-5:1995 history

• 1995 BS 6897-5:1995 Experimental determination of mechanical mobility - Measurement using impact excitation with an exciter which is not attached to the structure