This presentation was made at the 2019 NAFEMS World Congress in Quebec Canada
The sound of a device can play an important role in shaping user perceptions or providing audible feedback to reinforce user interactions and behaviours. Increasingly, device developers seek to design a particular acoustic quality into products. The study presented here explores the capability of Abaqus to model sound emission from mechanical impacts in complex devices.
A method was established for the simulation of acoustic emission, using explicit solvers to predict the dynamic structural behaviour. This was then validated against a physical test case, in which a ball bearing was dropped from known heights onto one of two Delrin® plates. To provide a novel acoustic response, the plates were cut to unique spoked geometries. Below the plate a laboratory microphone captured sound from the impact.
With refinement of the simulation methodology, very close correlation in the peak amplitude was achieved across different tests. Prediction of loudness with a good level of confidence was shown. However, a fundamental limitation of the explicit solution method used was found to poor replication of frequency and damping behaviour. This should not deter the use of the method in ‘volume-only’ applications.
With a robust approach to loudness simulation established, the methods were applied to investigate undesirable noise emission from a complex medical device interaction. Modelling in Abaqus identified the physical components contributing most significantly to acoustic emission. Furthermore, close analysis revealed several distinct impacts. The understanding gained from simulation has allowed subsequent optimisation of the geometry to be targeted and efficient.
|Date||18th June 2019|
|Organisation||Crux Product Design|