It was an interesting case study where an actual problem felt in a running vehicle in the highway is discussed. The vehicle shows ride disturbance from the viewpoint of vibration comfort inside the car. It was initially thought to be due to certain problems in the car. The observation was later verified, by conducting the same trial (with the same tyre set) in another vehicle and finally by changing the front tyre (with another) which confirmed that the disturbance is due to one of the tyre and its interaction with the vehicle. Then this tyre was identified and analysed to find out the root cause of the problem. Since, vibration is a very integral part of the ride comfort, it was objectively measured in all three vehicle axes to find out the direction of the vibration forces causing this discomfort. It was found that longitudinal force variation due to the tyre nonuniforrnity of the structure (called as tyre roughness) is responsible to generate the discomfort force. To identify the longitudinal force variation in a tyre a test was done in a high speed uniformity machine which shows that longitudinal force changes more with speed, even in the moderate speed range under study (40 - 120 kmph). The variation of longitudinal force was to a certain extent found to change the rolling resistance force with the change in speed as the latter is also due to the longitudinal force generated at the contact footprint. From the vibration spectra at different locations in the vehicle i.e at steering wheel and at floor, it was found that low frequency vibration is mainly responsible to cause tactile discomfort. Modal analysis of the tyre structure has confirmed that the resonance peaks of tyre structure and vehicle also fall in the same zone which probably enhances the resonance of the whole vehicle and thus the annoyance. This study has helped us reach to the root cause of the ride disturbance which is the most finer attributes of the vehicle that a customer is looking at the new generation vehicle. In this paper, a case study has been presented in which a ride problem was noticed in a running vehicle at low to moderate speed on a smooth road. Ride comfort was subjectively evaluated and vibrations at different inside locations of a running vehicle were objectively measured to characterise the vibration feature. Results are correlated with the tyre properties like high-speed uniformity, rolling resistance and modal properties of the tyre. The problem was found due to the longitudinal force variation of the tyre, which caused vibration at steering wheel as well as floor pan. Although these were low frequency disturbance, it might cause fatigue to the passenger on long exposure. Modal properties of the tyre also show the interactive resonances at low frequency, which probably affects the overall ride disturbance.
Tyre properties and vehicle ride comfort
Reifeneigenschaften und Fahrzeugfahrkomfort
2005
10 Seiten, 9 Bilder, 2 Tabellen, 19 Quellen
Conference paper
English
Investigation of Tyre Ride Comfort Performance on Electric Vehicle
SAE Technical Papers | 2023
|Ride comfort 3D tyre model: description and validation
Automotive engineering | 1998
|Ride Comfort 3D Tyre Model: Description and Validation
British Library Conference Proceedings | 1998
|Ride comfort 3D tyre model: description and validation
Tema Archive | 1998
|A Ride Comfort Tyre Model for Vibration Analysis in Full Vehicle Simulations
British Library Conference Proceedings | 1996
|