Dual-mass flywheels with tuned vibration absorbers for application in heavy-duty truck powertrains

As the heavy-duty combustion engine development goes towards lower rotational speeds and higher cylinder pressures, the torsional vibrations increase. There is therefore a need to identify and study new types of vibration absorbers that can reduce the level of torsional vibrations transmitted from the engine to the gearbox. In this work, the concept of a dual-mass flywheel combined with a tuned vibration absorber is analysed. The tuned vibration absorber efficiently reduces the vibration amplitudes for engine load frequencies near the tuning frequency, but it also introduces an additional resonance into the system. By placing the tuned vibration absorber on an intermediate flange between the two dual-mass flywheels, the introduced resonance frequency will be lower than the tuning frequency and a resonance in operating engine speed range can be avoided. Numerical simulations are used to show how the torsional vibration amplitudes in a heavy-duty truck powertrain are affected by the tuned vibration absorber and how the different parameters of the tuned vibration absorber and the dual-mass flywheel affect the torsional vibrations and the resonance frequencies.

A Study on the Application of Tuned Vibration Absorbers to Nominally Cyclic Structures

The vibration absorber or tuned mass damper is a well-known mechanism, where a small mass connected to a larger structure is used to redirect vibration energy and provide reduction in vibration amplitudes at desired locations and frequencies. While tuned vibration absorbers have been widely applied for damping of mechanical systems, the concept remains largely unexplored in the design of dampers for bladed disks. This paper investigates whether such a vibration absorption mechanism is feasible for such nominally cyclic symmetric structures which are characterized by double modes, high modal density, and sensitivity to uncertainties such as mistuning. The single-degree of freedom vibration absorber concept is extended for application to this complex modal space, and lumped mass models are used for analysis. Trends in effectiveness of a vibration absorption based damper are explored by studying sensitivities to various parameters such as stiffness and damping at various locations. Effects of mistuning across sectors and locations of damper attachment are also considered. The results of the study establish the feasibility of the vibration absorption mechanism for application in blisks, and encourage further exploration of the concept, possibly in conjunction with other well-established damping mechanisms such as friction.

Effect of SSI on Vibration Control of Structures with Tuned Vibration Absorbers

This paper investigates the effect of considering soil-structure interaction (SSI) in seismic responses of reinforced concrete (RC) chimneys installed by distributed tuned vibration absorbers vertically (d-MTVAs). A multimode control approach is used to design the d-MTVAs. Two-dimensional (2D) RC chimney is the assembly of beam elements. Frequency-independent constants for the springs and dashpots are used for modeling the raft and the surrounding soil. The equations of motion for nonclassically damped systems are derived and solved using Newmark’s method. The effectiveness of the d-MTVAs is weighed against the case of single tuned vibration absorber (STVA), d-MTVAs suppressing the first modal responses (d-MTVAs-1), and randomly distributed MTVAs (ad-MTVAs). Additionally, parametric studies are conducted for varying mass and damping ratios in the STVA, d-MTVAs-1, ad-MTVAs, and d-MTVAs. In order to show the efficiency in the STVA, d-MTVAs-1, ad-MTVAs, and d-MTVAs cases, responses (displacement and acceleration) at top of the RC chimney while subjected to different real earthquake excitations are computed. It is concluded that the STVA, d-MTVAs-1, ad-MTVAs, and d-MTVAs are effective in response mitigation of the RC chimney; however, d-MTVAs are more efficient while considering equal total mass of the TVA(s). Moreover, the soil type significantly influenced the design parameters of the STVA/d-MTVAs-1/ad-MTVAs/d-MTVAs and seismic response of the RC chimney.