Experimental modal analysis of an automotive powertrain

Abstract

The work is devoted to study the dynamic properties of a powertrain, performing an experimental modal analysis (EMA). The aim is to determinate structural modes and frequency response function (FRF) using an experimental approach. Two types of excitation mechanism are applied and compared for the EMA: a modal exciter (electromagnetic shaker system) and an impact hammer. Both the analyses with modal shaker and with impact hammer are carried on measuring the acceleration of the structure in the same set of eighty-one points. In both cases, the excitation is performed along three directions (vertical, lateral and longitudinal with respect to the structure). The two different modal analysis methodologies are described, and results (modal parameters such as natural frequencies, damping ratios and modal shapes are identified with commercial software) are compared. The comparison is made in term of result accuracy, reliability and testing time required. © (2010) Trans Tech Publications, Switzerland.