Acoustics and vibration

Vibration characterisation and improvement of acoustic comfort in vehicle interiors

Comfort innovation

The acoustic perception of the user is of great importance for the comfort in the vehicle and the brand image, being the natural trend in the automotive sector to seek greater interior comfort.

In addition, electric propulsion systems and new suspension schemes for the automotive industry result in increasingly quieter environments inside the vehicle cabin, which means that noises traditionally imperceptible in vehicles with internal combustion engines become annoying in vehicles with quieter engines.

With the aim of increasing the acoustic comfort of the vehicle interior, the acoustics and vibration laboratory develops new working methodologies and performs tests in the field of acoustics and vibration, as well as combined tests.

Vibration studies

Acoustics studies

  • Measurement and analysis of component noise under real operating conditions.
  • Measurement and analysis of squeak & rattle under operating conditions produced by vibration.
  • Measurement of sound pressure, vibroacoustic transfer functions and time/frequency analysis.
  • Acoustic characterisation of materials (absorption coefficient and acoustic transmission losses) by impedance tube.
  • Acquisition of in-vehicle sound pressure and acceleration time signals.
  • Vibration tests combined with temperature for vibroacoustic and structural analysis of components.

Vibration equipment

  • High-capacity multiaxial electrohydraulic shaker (6 degrees of freedom; combined with climatic chamber).
  • Multiaxial electrohydraulic shaker (6 degrees of freedom; combined with anechoic chamber).
  • Multiaxial electrohydraulic shaker (6 degrees of freedom; combined with climatic chamber).
  • 54 kN biaxial electrodynamic exciter combined with climatic chamber.
  • 35.6 kN biaxial electrodynamic exciter combined with climatic chamber.
  • 22.2 kN uniaxial electrodynamic exciter combined with semi-anechoic chamber or climatic chamber.
  • Equipment for Experimental Modal Analysis of components and complex structures such as complete body-in-white (multichannel acquisition systems, impact hammers, modal shakers).

On-board acquisition systems and acoustic chambers

  • LMS Scadas acquisition system and LMS Test.Lab software (48 acquisition channels) mainly oriented to structural and Experimental Modal Analysis tests.
  • Bruel & Kjaer LAN-XI acquisition system and BK Connect software (24 acquisition channels / signal generation) oriented to recording tests and noise frequency analysis.
  • Semi-anechoic chamber (22,000 L, acoustic analysis of operating noise and components subjected to vertical vibration).
  • Anechoic chamber (100,000 L, studies of operating noise in vehicle and noise analysis of components under multiaxial vibration – road or track signals)
  • On-board acquisition systems for noise and vibration recording. Sensors: free field microphones, binaural microphones, uniaxial and triaxial accelerometers, force sensors.