ISO 9052-1 provides for the determination of the dynamic stiffness of materials used under floating floors in dwellings. The measurement technique is based on the resonant frequency of the fundamental vertical vibration of a spring-mass system achieved in the test. Either sinusoidal, white noise or pulse signals are used. When using a sinusoidal excitation signal, the tested material shows a dependence between the resonant frequency and the amplitude of the excitation force. A specific procedure for this calculation is given in the standard. There is no similar procedure for the pulse signal method, even though the amplitude of the excitation pulse may affect the resonant frequency. In this paper, a measurement procedure using both sinusoidal and pulse signals techniques is described and analyzed in order to determine the correct value of the dynamic stiffness of a material in relation to the real dependence of the resonant frequency by excitation force amplitude. The tests using sinusoidal signals show that the relation between the resonant frequency and the force amplitude is inverse with a logarithmic trend. The results are in agreement with those of the pulse signals, which underwent a similar analysis.
On the dynamic stiffness of materials used under floating floors: analysis of the resonance frequency dependence by excitation force amplitude using different measurement techniques
BETTARELLO, Federica;FAUSTI, Patrizio;
2007
Abstract
ISO 9052-1 provides for the determination of the dynamic stiffness of materials used under floating floors in dwellings. The measurement technique is based on the resonant frequency of the fundamental vertical vibration of a spring-mass system achieved in the test. Either sinusoidal, white noise or pulse signals are used. When using a sinusoidal excitation signal, the tested material shows a dependence between the resonant frequency and the amplitude of the excitation force. A specific procedure for this calculation is given in the standard. There is no similar procedure for the pulse signal method, even though the amplitude of the excitation pulse may affect the resonant frequency. In this paper, a measurement procedure using both sinusoidal and pulse signals techniques is described and analyzed in order to determine the correct value of the dynamic stiffness of a material in relation to the real dependence of the resonant frequency by excitation force amplitude. The tests using sinusoidal signals show that the relation between the resonant frequency and the force amplitude is inverse with a logarithmic trend. The results are in agreement with those of the pulse signals, which underwent a similar analysis.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
