Digital Twin Modal Analysis - Loudspeaker Redesign
Finite element modal analysis of a B&W DM602 S2 loudspeaker enclosure using Siemens NX (SOL103). Successfully shifted the 7th natural frequency above 120 Hz through strategic reinforcement and mass placement.
Duration
Spring 2025
Role
Developer
Institution
NTNU
Status
Completed
Technologies Used
Overview
This Digital Twins portfolio project applied finite element modal analysis to redesign a loudspeaker cabinet for improved acoustic performance. Using Siemens NX SOL103 with Lanczos eigenvalue extraction, the 7th mode was successfully shifted from 89.27 Hz to 143.56 Hz through internal bracing and strategic mass placement. The project demonstrates skills in Structural Health Monitoring (SHM) and Condition Monitoring (CM) applications.
Problem Statement
Shift the 7th natural vibration mode and all higher modes above 120 Hz to prevent structural resonance effects in critical audible frequencies, improving the loudspeaker's acoustic fidelity.
Challenges & Solutions
| Challenge | Solution | Outcome |
|---|---|---|
| Mode Below Target Frequency | Added internal beam braces and mass elements (0.5kg, 0.3kg, 0.1kg, 0.37kg) at strategic locations | Mode 7 shifted from 89.27 Hz to 143.56 Hz |
| Geometry Complexity | Simplified CAD model by removing non-essential features while preserving stiffness profile | Reduced computational cost while maintaining modal accuracy |
| Material Modeling | Used polyethylene as simulation proxy for wood-like behavior | Consistent isotropic material for reliable FEM results |