TY - BOOK
T1 - Evaluation of MF-swift for durability simulations
AU - Leenders, S.
A2 - Besselink, I.J.M.
A2 - Knorr, S.
N1 - Traineeship report. - DC 2011.003
PY - 2011
Y1 - 2011
N2 - Daimler AG uses simulation tools to predict how the car will perform before testing takes place.
The simulations are important because it reduces costs and time. One of the important topics is
durability. A customer wants a car which is reliable. Therefore several test are carried out like
for example driving over cleats or through potholes. These test have a major impact to the suspension
and chassis components. During the design of the suspension it’s important to simulate
these tests. To predict the outcome of the simulation accurately the forces generated by the tyre
need to be known. Therefore it is crucial to have a correct simulation model of the tyre. Several
tyre models exist in the market like MF-Swift and Ftire. Because there are multiple tyre models
available, it is necessary for Daimler to know how these models perform and make a comparison.
The objective of this report is the evaluation of MF-Swift for durability load simulations. Various
road obstacles are used to evaluate the performance of MF-Swift. Some of these simulations
are compared with measurement data and other simulations with a different tyre model, Ftire.
The resulting tyre forces are analyzed in the time domain and using damage calculations.
The first step is to generate a tyre property file. This file contains all the required parameters
of the tyre model. Daimler has two measurement sets available of tests executed in Aachen and
Karlsruhe. With these measurement sets the required parameters for MF-Swift can be identified.
The in-plane dynamics are parameterized with the Aachen measurements and the out-of-plane
dynamics with the Karlsruhe measurements. Combining two measurement sets is not an ideal
situation. The reason for this was that the out-of-plane dynamics were not excited in the Aachen
measurements.
The first part of this report evaluates the low speed enveloping behaviour and some dynamic
cleat experiments. Simulations show that MF-Swift has a better match with the measurements
for the enveloping behaviour compared to Ftire. However, if only the peak-to-peak values are analyzed
it is visible that the general trend for MF-Swift is a higher vertical force while Ftire has a
lower vertical force when they are compared with the measurements. The longitudinal forces of
both models matches rather well with the measurements.
The cleat experiments used for the parametrization process are simulated with the two tyre models.
Both models are able to match the vertical force reasonably well, but some differences exist
for the longitudinal force. MF-Swift is able to describe the peak-to-peak value for the out-of-plane
measurement rather well, for the in-plane case MF-Swift is only able to match the negative peak.
Ftire isn’t able to match the peak-to-peak values for both in-plane and out-of-plane. The difference
for the out-of-plane is probably caused by the fact that it was not possible to simulate Ftire on a
drum.
The second part contains simulations for rough road conditions. The obstacles which are used
are a cleat, oblique cleat, pothole and belgian blocks. The simulations show that MF-Swift has a
higher vertical force compared to Ftire for all the simulations except for the cleat oblique manoeuvre.
The trend for the longitudinal force is that Ftire always has a higher force. The differences
were also shown by the damage sums. Those damage sums are evaluated for different x-positions
of the cleat. MF-Swift has a very consistent behaviour, while Ftire sometimes shows a certain position
dependent behaviour which originates from the discretisation of the tyre.
AB - Daimler AG uses simulation tools to predict how the car will perform before testing takes place.
The simulations are important because it reduces costs and time. One of the important topics is
durability. A customer wants a car which is reliable. Therefore several test are carried out like
for example driving over cleats or through potholes. These test have a major impact to the suspension
and chassis components. During the design of the suspension it’s important to simulate
these tests. To predict the outcome of the simulation accurately the forces generated by the tyre
need to be known. Therefore it is crucial to have a correct simulation model of the tyre. Several
tyre models exist in the market like MF-Swift and Ftire. Because there are multiple tyre models
available, it is necessary for Daimler to know how these models perform and make a comparison.
The objective of this report is the evaluation of MF-Swift for durability load simulations. Various
road obstacles are used to evaluate the performance of MF-Swift. Some of these simulations
are compared with measurement data and other simulations with a different tyre model, Ftire.
The resulting tyre forces are analyzed in the time domain and using damage calculations.
The first step is to generate a tyre property file. This file contains all the required parameters
of the tyre model. Daimler has two measurement sets available of tests executed in Aachen and
Karlsruhe. With these measurement sets the required parameters for MF-Swift can be identified.
The in-plane dynamics are parameterized with the Aachen measurements and the out-of-plane
dynamics with the Karlsruhe measurements. Combining two measurement sets is not an ideal
situation. The reason for this was that the out-of-plane dynamics were not excited in the Aachen
measurements.
The first part of this report evaluates the low speed enveloping behaviour and some dynamic
cleat experiments. Simulations show that MF-Swift has a better match with the measurements
for the enveloping behaviour compared to Ftire. However, if only the peak-to-peak values are analyzed
it is visible that the general trend for MF-Swift is a higher vertical force while Ftire has a
lower vertical force when they are compared with the measurements. The longitudinal forces of
both models matches rather well with the measurements.
The cleat experiments used for the parametrization process are simulated with the two tyre models.
Both models are able to match the vertical force reasonably well, but some differences exist
for the longitudinal force. MF-Swift is able to describe the peak-to-peak value for the out-of-plane
measurement rather well, for the in-plane case MF-Swift is only able to match the negative peak.
Ftire isn’t able to match the peak-to-peak values for both in-plane and out-of-plane. The difference
for the out-of-plane is probably caused by the fact that it was not possible to simulate Ftire on a
drum.
The second part contains simulations for rough road conditions. The obstacles which are used
are a cleat, oblique cleat, pothole and belgian blocks. The simulations show that MF-Swift has a
higher vertical force compared to Ftire for all the simulations except for the cleat oblique manoeuvre.
The trend for the longitudinal force is that Ftire always has a higher force. The differences
were also shown by the damage sums. Those damage sums are evaluated for different x-positions
of the cleat. MF-Swift has a very consistent behaviour, while Ftire sometimes shows a certain position
dependent behaviour which originates from the discretisation of the tyre.
M3 - Report
T3 - D&C
BT - Evaluation of MF-swift for durability simulations
PB - Eindhoven University of Technology
CY - Eindhoven
ER -