A Unique Methodology to Evaluate the Structural Robustness of a Dual-Mass Flywheel under Real-World Usage Conditions 2020-28-0475

Dual mass flywheel (DMF) is an excellent solution to improve the noise, vibration and harshness (NVH) characteristic of any vehicle by isolating the driveline from the engine torsional vibrations. For the same reason, DMFs are widely used in high power-density diesel and gasoline engines. However, the real-world usage conditions pose a lot of challenges to the structural robustness of the DMF. In the present work, a new methodology is developed to evaluate the robustness of a DMF fitted in a compact sports utility vehicle (SUV) with rear-wheel drive architecture.

The abuse conditions (mis-gear, sudden braking, etc) in the real-world usage could lead to a sudden engine stall leading to an abnormally high angular deceleration of the driveline components. The higher rate of deceleration coupled with the higher rotational moment of inertia of the systems might end up in introducing a significantly high impact torque on the DMF. Hence, prolonged usage of the vehicle in abuse conditions could lead to a structural failure of the DMF which needs to be assessed during the development stage of a vehicle. In the present work, the authors propose a unique methodology to assess the structural robustness of any DMF. The methodology is a combination of multiple mis-gear shifts and abuse maneuvers creating a high impact torque. The impact torque throughout the testing was measured to establish a correlation with real-world failures. The effectiveness of the methodology is confirmed by comparing the results of the tested DMFs with the long duration high mileage durability DMFs. Moreover, the duration of the methodology is designed to be extremely short that any DMF could be validated within 2 days.

In the present work, based on the results of this proposed methodology, the robustness of the DMF could be improved by modifying the internal child parts of the DMF. The paper explains the typical robustness measures needed inside the DMF to avoid real-world structural failures.