Automotive plant / Noise-control simulation
Ranking eight noise-control measures for a press line before the purchase order
An automotive plant on the Eastern Seaboard had a list of eight noise-control measures for a stamping press line and wanted to know what each would deliver before ordering. We measured, located the sources with the acoustic camera, and simulated all eight measures cumulatively in SoundPLAN. The first four on the list added up to less than 3 dB at the operator positions; the absorption panels, roof cover and front cover were what delivered 10–11 dB.
The problem
Operator positions sat at 88–91 dBA. Some of the measures had already been fitted to a neighbouring line with unconvincing results, and the plant needed evidence for which items to fund next.
Our approach
- 1Measured Leq at nine positions across the 120 m × 60 m press area with Class 1 instruments
- 2Located the dominant sources and the reflecting surfaces (walls, roof) with the acoustic camera, to set source sound power and surface absorption in the model
- 3Built a SoundPLAN model to VDI 3760 and ISO 9613-2, calibrated against the measured levels at all nine positions
- 4Simulated the eight measures cumulatively — delivery tunnel wall, machine-side walls on the operator and robot sides, soundproof curtain, soundproof roof, absorption panels, mass-loaded roof cover and front cover — and reported the reduction at every position with the calculation uncertainty
Standards applied
Key numbers
91.0 → 79.8 dBA
Loudest position before/after (simulated)
8, cumulative
Measures simulated
≤ 2.5 dB
First four measures combined
±2.6 to ±3.6 dB
Calculation uncertainty
Outcome
Measured levels ran from 65.9 to 91.0 dBA, with operator positions at 88.3–91.0 dBA. The first four measures (walls and curtain) delivered at most 2.5 dB at the loudest positions, consistent with what the plant had seen on the neighbouring line. The material reductions came from the absorption panels (a further 3–6 dB), the mass-loaded roof cover and the front cover. With all eight in place, the loudest positions fell from 89.3 to 78.8, 91.0 to 79.8 and 90.4 to 79.8 dBA — a 10–11 dB reduction — with a calculation uncertainty of ±2.6 to ±3.6 dB. The plant re-ordered its investment by effect per baht.