Mecanum - Noise Control Services

Characterization services

Mecanum offers a full characterization services of porous and damping materials used for noise control. The characterization uses state-of-the-art equipments and can characterize all the porous and damping material properties. These properties are required to optimize materials and sound packages, to perform quality control, and to use as input parameters in acoustical simulation software. The porous material properties are those based on the Biot's poroelasticity theory and related equivalent fluid models (Johnson-Allard, Johnson-Lafarge, Attenborough, Delany-Bazley, Miki, etc.).

Types of porous materials

See Slideshow (left): Polymeric foams • fiber materials • fabrics • recycled fibers • perforated plates • resistive films • felts • carpets • acoustic tiles • granular materials

Porous material characterization

Open porosity and bulk density • Static airflow resistivity and permeability • Tortuosity • Viscous and thermal characteristic lengths • Elastic properties (Young's modulus, Poisson's ratio, damping loss) • Thermal permeability • Specific surface

Impedance and transmission tube tests

Normal sound absorption • Surface impedance • Reflection coefficient • Normal sound transmission loss • Characteristic impedance • Propagation constant or wave number • Dynamic density • Dynamic compressibility

Damping material properties

Frequency dependent Young's modulus • Frequency dependent damping loss factor • Frequency dependent shear modulus