Auralization of Sound Emitted by an Excited Structure

Auralisering af lyd udbredt af en vibrerende struktur

Claumarch, Christian Weirum

4. term

Acoustics and Audio Technology, Master

2018

2018-08-20

205

I udvikling af mekaniske produkter er tid og omkostninger afgørende. En måde at reducere begge dele er simulationsdrevet udvikling, hvor ingeniører bruger computermodeller i stedet for at bygge mange prototyper. Denne afhandling undersøger, om lydfeltet omkring en vibrerende struktur—her en plade—kan forudsiges ved hjælp af modellering, så man kan lytte til et design, før det er bygget. Problemet opdeles i tre dele: (1) hvordan pladen vibrerer, (2) hvordan vibrationerne udsender lyd til luften, og (3) hvordan lyden opleves af en lytter (auralisering). Arbejdet kombinerer finite element-analyse (FEM)—en beregningsmetode der opdeler strukturen i mange små elementer for at finde dens vibrationer—med akustisk modellering for at estimere lydudstrålingen. Simuleringerne sammenlignes med målinger og analytiske beregninger for at vurdere, om FEM-resultaterne er tilstrækkeligt nøjagtige til at generere lyd. Algoritmen kan producere lyd, som minder om lyden fra den fysiske plade, men de to er ikke identiske. Både objektive mål og subjektive vurderinger viser mærkbare forskelle, hvilket indikerer, at nøjagtigheden endnu ikke er tilstrækkelig til fuldstændig at gengive den virkelige lyd.

In mechanical product development, time and cost are critical. One approach to reducing both is simulation‑driven development, where engineers rely on computer models instead of building many prototypes. This thesis examines whether the sound field around a vibrating structure—a plate—can be predicted through modeling, allowing people to listen to a design before it is built. The problem is divided into three parts: (1) how the plate vibrates, (2) how those vibrations radiate sound into the air, and (3) how the sound is perceived by a listener (auralization). The work combines finite element analysis (FEA)—a method that divides the structure into many small elements to compute its vibrations—with acoustic modeling to estimate sound radiation. Simulations are compared with measurements and analytical calculations to assess whether FEA results are accurate enough for sound generation. The algorithm produces audio that resembles the sound of the physical plate, but they are not identical. Both objective metrics and subjective perception show noticeable differences, indicating that accuracy is not yet sufficient to fully reproduce the real sound.

[This abstract was generated with the help of AI]

Auralisering ; Vibration ; Finite element analysis ; FEM ; FEA ; Radiation ; Binaural

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