Acoustics – Noise Vibration Harshness

The knowledge of the acoustic behaviour is fundamental within the development cycle of a new product or new system components. Especially the acoustic performance, next to the quality, efficiency as well as reliability, will decide about success or defeat of a new product in the consumer market.

We can offer our deep knowledge in numerical methods like the Finite Element Methode to predict the vibration and acoustic behavior of your product early in the development cycle. We are able to perform a highly accurate FEM guided Modal Analysis based on CAD models. The extracted eigenfrequencies and eigenforms from the FEM computations are first indicators of the acoustical performance of the final product. Resonance and acoustic problems may occur if the excitation forces acting on the structure are close to the determined eigenfrequencies. In that case we will provide you with specific design guidelines to improve the structural behavior so that resonance and acoustical problems can be ruled out.

Once the modal analysis is done we are able to compute the scattered acoustic field using state of the art Boundary Element Methods. The acoustic BEM formulation is a solution strategy for the Helmholtz wave equation which is transferred to an equivalent surface integral formulation known as Kirchhoff-Helmholtz equation. Taking the results from an inhomogeneous modal analysis in terms of surface velocities as boundary conditions, the BEM method can compute the main features of the radiated sound field like sound pressure or sound power levels over a wide range of frequencies.

Next to the numerical methods we have already mentioned, we offer you the possibility to participate by our qualifications in experimental methods in acoustics and vibration analysis. Due to our link to external partners you can participate by the possibility to perform highly accurate acoustic measurements in an acoustic chamber to determine all needed quantities for final product acceptance test. Using state of the art low noise microphones and signal conditioning equipment complying IEC 61672 and IEC 61043 standards we can determine the overall sound power level according to DIN EN ISO 3745 – 3747 or DIN EN ISO 9614. The localization of disturbing noise sources at machineries or specific components, which might be a serious problem in some cases, can be done in terms of sound intensity mapping with a sound intensity probe or an acoustic camera system.

In addition to measure acoustic quantities we are able to provide you with results from Experimental Modal Analysis or Operating Deflection Shape analysis as well as vibration analysis according to DIN ISO 10816.

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