Search Results

Airflow resistivity is one of the most important parameters in the study of the physical properties of porous acoustic materials. This parameter is fundamental for the correct evaluation of sound absorption of acoustic materials and is needed in all the theoretical models. In the present work, airflow resistivity of porous materials is determined under effective operating conditions inside a vehicle (temperature, compression of the panels). Starting from the discussion on the measurement uncertainty, experimental data of airflow resistivity, measured as a function of temperature and applied static loads, are presented. By introducing the measured values in a SEA model of a typical vehicle panel, the foreseen values of acoustic absorption due to variation of temperature and static load are determined and presented.

This work describes a numerical methodology based on the Finite Element approach able to simulate the dynamic maneuver of the full vehicle running on fatigue reference roads. The basic idea of present work stays in combining a moderately complex and general finite element tire model with traditional full-vehicle methods, including both implicit and explicit finite element techniques, in order to predict the dynamic response of the car running on the real fatigue reference roads. Some issues related to application of tire finite element model to a long simulation time in an explicit solution have been discussed. The best integration strategy between implicit and explicit solutions, based on pure sequential and/or the combined sequential and co-simulation mode is discussed. The real fatigue load is digitalized and implemented as a rigid body in the explicit code.