Abstract
In-situ transfer path analysis is a diagnostic method used to analyse the propagation of noise and vibration through complex built-up structures. Its defining feature is the independent characterisation of an assembly’s active components (i.e. vibration sources) by their blocked forces. This independent characterisation enables the downstream structural modification of an assembly without affecting the sources’ operational characteristics. In practical engineering structures, however, there is often a need to alter or replace components that reside within a vibration source, for example resilient mounts. An upstream structural modification of this sort would alter the blocked force and thus invalidate any response predictions made thereafter. Hence, an alternative approach is required. In the present paper a transmissibility-based structural modification method is introduced. We derive a set of equations that relate the blocked force and forward transfer functions obtained from an initial assembly, to those of an upstream modified assembly. Exact formulations are provided, together with first and zeroth order approximations for resiliently coupled structures. These component replacement expressions are verified by numerical examples.
Highlights
Transfer Path Analysis (TPA) is a diagnostic method used for analysing the propagation of noise and vibration in complex built-up structures, for example, vehicles, buildings, ships, etc
To achieve the above we propose a novel transmissibility-based structural modification method, Component Replacement TPA (CR-TPA)
Error analysis The results presented above considered only a single initial and replacement coupling element, and so provide little information regarding the sensitivity of the CR-TPA approximations to their key assumption; an impedance mismatch between source and coupling element
Summary
Transfer Path Analysis (TPA) is a diagnostic method used for analysing the propagation of noise and vibration in complex built-up structures, for example, vehicles, buildings, ships, etc. In an in-situ TPA the active components of an assembly (i.e. vibration sources) are each characterised by their blocked force; the force required to constrain their interface degrees of freedom (DoFs) such that their velocity ( displacement and acceleration) is zero. The contribution of each active component to an operational response is determined using transfer functions measured between the source-receiver interface and the chosen target DoF. Based on their relative contributions, an engineer is able to identify troublesome vibration sources/transmission paths and investigate appropriate design changes. Its application provides the modified blocked force and forward transfer function, according to a known component replacement, and enables response predictions to be made in the modified assembly without requiring re-characterisation of the blocked force.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
