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An automotive powertrain is a system that is designed to transmit torque from the engine to the wheels of the vehicle, allowing it to move. The working principle of most of the vehicle engines is the internal combustion, which causes the torque generated by this engine to have important oscillatory components, which cause the powertrain to vibrate and generate noise, which is undesired. In order to control this vibration, among many engineering solutions is the centrifugal pendulum vibration absorber (CPVA), whose dynamic behaviour turns it is capable of reducing the amplitude of important order components of the powertrain. It is usually installed on the flywheel of the vehicle, although it is possible to install it in other parts, such as the clutch disk. Although the CPVA is an important type of passive vibration absorber, it was still not found in the literature a parametrized formulation which can be applied to any vibration absorber of this kind. For this reason, the aim of this work is to propose a formulation based on dimensionless parameters, which can be applied to any CPVA. With this formulation, the dynamic behaviour of a simple 2DOF torsional system with a CPVA, spinning at constant speed, is verified. It is important to mention that this work is the first part of a two part work. In the second part, this formulation is applied to a more complex system with a CPVA, and results are shown to be coherent with the analyses shown here.

This work is the second and last part of a study whose aim is to present the vibrational aspects of a system with a centrifugal pendulum vibration absorber (i.e. CPVA). The aim of this work, specifically, is to develop a mathematical model of a front engine–front wheel drive powertrain to study gear rattle phenomenon, and to install on its clutch disk’s flange a CPVA in order to understand what are the effects of this device on the dynamics of this system. Results from the linear analysis show that the eigenfrequencies of the system vary with the engine speed. They oscillate between the eigenvalues of the system without the CPVA and, for regions away from the tuning frequency of the pendulum, which is the second order of rotation of the engine, the behaviour of the system remains the same. However, near the tuning frequency of the pendulum, the behaviour of the system varies very much, and the amplitude of vibration of the gearbox’s inner parts diminishes. Simulations of the powertrain without and with the nonlinear model of the studied device show that its presence reduces dramatically the vibrations inside the gearbox and its nonlinear character does not influence the effectiveness of this solution.