What is ISO 21955 about?
ISO 21955 specifies a method to predict the dynamic forces generated by an active component on a receiving structure from measurement on a test bench.
ISO 21955 sets out the requirements applicable to test benches and setup measurement conditions of dynamic forces: a criterion of validity of transfer functions measurements can be established for example.
The objective is to evaluate noise and vibrations generated by active components mounted on receiving structures, including the possibility to optimize vibration isolators.
ISO 21955 can be applied to different systems connected to a building, such as a compressor or a power generator, or to systems connected to a vehicle body, such as an engine powertrain or an electrical actuator, for example.
Who is ISO 21955 for?
ISO 21955 on acoustics is relevant to:
- Acoustics engineer
- Electrical/Electronic engineer
- Manufacturer of compressor, power generator, electrical actuator
Why should you use ISO 21955?
The vibroacoustic behaviour of products has become a major challenge not only in terms of user-health protection through regulations, but also in terms of sound quality for safety, quality perception, and attractiveness.
ISO 21955 help the user predict the component behaviour in a particular assembly. The theoretical background is laid in Annex A. The user of ISO 21955 is guided all along the experimental procedure enabling to reach this objective:
- Static characterization of the component, the test bench and the receiving structure.
- Force measurement: the standard proposes here direct and indirect methods. Indirect methods are generally easier to implement, but they need a particular focus on the measurement quality and matrix inversion.
- Interface integration (connecting device).
- Prediction of the behaviour of the component/receiving structure assembly.
Annex B and C on Frequency response functions measurement and Dynamic forces measurement respectively guide the user to measure both transfer functions and dynamic forces.
The data obtained and assessed in ISO 21955 can be used:
- As part of a specification between suppliers and integrators
- As input data of numerical vibroacoustic simulation models
- To drive the modification of the physical structure or the interface to improve the vibroacoustic behaviour
