A study on torsional vibration attenuation in automotive drivetrains using absorbers with smooth and non-smooth nonlinearities

• Published in: Applied Mathematical Modelling 2017-06, Vol.46, p.674-690
• Main Authors: Haris, Ahmed, Motato, Eliot, Theodossiades, Stephanos, Rahnejat, Homer, Kelly, Patrick, Vakakis, Alexander, Bergman, Lawrence A, McFarland, D. Michael
• Format: Article
• Language: English
• Subjects: 5th order nonlinearity; Automobile industry; Automobiles; Automotive engineering; Automotive engines; Automotive parts; Broadband; Clutches; Cubic nonlinearity; Dampers; Damping; Devices; Dissipation; Energy consumption; Energy transfer; Flywheels; Frequencies; Mathematical models; Narrowband; Nonlinear response; Powertrain; Stiffness; Superchargers; Targeted energy transfer; Torsional oscillations; Torsional vibration; Vehicular drivetrain; Vibration; Vibration control; Vibration isolators; Vibro-impact
• ISSN: 0307-904X; 1088-8691; 0307-904X
• DOI: 10.1016/j.apm.2016.09.030

•The effect of three NES types in reducing drivetrain torsional vibrations is examined.•NES with cubic stiffness can reduce vibrations for a range of high frequencies.•It was not possible to achieve broadband vibration reduction at a low frequency range. The automotive industry is predominantly driven by legislations on stringent emissions. This has led to the introduction of downsized engines, incorporating turbocharging to maintain output power. As downsized engines have higher combustion pressures, the resulting torsional oscillations (engine order vibrations) are of broadband nature with an increasing severity, which affect noise and vibration response of the drive train system. Palliative devices, such as clutch pre-dampers and dual mass flywheel have been used to mitigate the effect of transmitted engine torsional oscillations. Nevertheless, the effectiveness of these palliative measures is confined to a narrow band of response frequencies. The nonlinear targeted energy transfer is a promising approach to study vibration mitigation within a broader range of frequencies, using nonlinear vibration absorbers (or nonlinear energy sinks – NESs). These devices would either redistribute vibration energy within the modal space of the primary structure, thus dissipating the vibrational energy more efficiently through structural damping, or passively absorb and locally dissipate a part of this energy (in a nearly irreversible manner) from the primary structure. The absence of a linear resonance frequency of an NES, enables its broadband operation (in contrast to the narrowband operation of current linear tuned mass dampers). Parametric studies are reported to determine the effectiveness of various smooth or non-smooth nonlinear stiffness characteristics of such absorbers. A reduced drivetrain model, incorporating single and multiple absorber attachments is used and comparison of the predictions to numerical integrations proves its efficacy.