A New Standardized Method to Characterize Acoustic Properties of Laminated Glass

Marc Rehfeld & Yohan Faucillon, Saint Gobain Glass

The mechanical impedance measurement (MIM) method has been set as ISO/PAS 16940 during the last ISO/TC160/SC2 meeting June 24th 2004 in Berlin. This method consists of fixing a beam of laminated glass on an impedance head, making them vibrate with a shaker, and measuring the transfer function between the force of excitation and the velocity response of the beam. The shape of the transfer function curve allows to know the frequencies and the damping of the vibration modes, related to the stiffness and the loss modulus of the interlayer. It is then possible to calculate a Sound Transmission Loss curve for comparative means, and Rw values. Temperature is fixed very precisely.

This method is much more precise that formerly existing ones to check the acoustic quality of interlayers. ISO/TC160 is dedicated to glass in building, but the method can also be used for automotive purpose. Automated version, more dedicated to Factory Production Control is also presented.

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The Authors

Mr. Marc Rehfeld Acoustics expert Compagnie de Saint Gobain Saint Gobain Glass CRDC Marc Rehfeld is responsible of the Acoustics/Numerical Modelling Team at the "Centre de Développement Industriel" (CDI), working both for Saint Gobain Glass and Saint Gobain Sekurit. He has over 25 ye... Read more