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**Harvard**

Johansson, D. och Karlsson, K. (2017) *Simulation models of dual mass flywheels*. Göteborg : Chalmers University of Technology (Diploma work - Department of Applied Mechanics, Chalmers University of Technology, Göteborg, Sweden, nr: 2017:18).

** BibTeX **

@mastersthesis{

Johansson2017,

author={Johansson, Daniel and Karlsson, Kim},

title={Simulation models of dual mass flywheels},

abstract={Heavy duty trucks are faced with strict requirements regarding exhaust emissions and fuel eciency. The
demands are achieved through downsizing and downspeeding. This introduces torsional vibrations in the
powertrain which, if not dealt with, will decrease life and comfort. One solution that deals with these vibrations
is the Dual Mass Flywheel that absorbs the vibrations.
The goal of this thesis is to develop and verify different computational models of a Dual Mass Flywheel and in
particular study how the friction between the arc-spring and the primary
ywheel affects the system.
Modelling is done in Python using the Newmark- method combined with Newton's method for numerical
simulations. The same model is also created in AVL Excite for verification. The friction between the arc-spring
and the primary
flywheel channel is modelled using the Coulomb friction model or an inverse tangent function.
It has been verified that the two computational models give similar results.
A method to approximate Coulomb friction has been developed in order to make the computational model
more stable. The friction depends on both spring compression and centripetal force due to the rotation of the
Dual Mass Flywheel. For a truck's operating speed the spring compression is the largest factor to frictional
losses with current selection of geometrical and structural parameters. The results show that with low friction
and low viscous damping resonance is not a significant problem even if it occurs at low engine speed. A study
about the number of masses needed to solve the friction model have been performed. It is concluded that the
friction moment has not converged using five spring masses. A method of achieving accurate results with few
masses is presented.
For a final conclusion about the dynamics of the Dual Mass Flywheel, the developed computational models
need to be validated using experimental data. Modifications of geometrical and structural parameters should
be done to fit the experiments.
Keywords:Torsional Vibrations, Dual Mass Flywheel, Python, AVL Excite Timing Drive, Computational
Models},

publisher={Institutionen för tillämpad mekanik, Dynamik, Chalmers tekniska högskola},

place={Göteborg},

year={2017},

series={Diploma work - Department of Applied Mechanics, Chalmers University of Technology, Göteborg, Sweden, no: 2017:18},

}

** RefWorks **

RT Generic

SR Electronic

ID 250346

A1 Johansson, Daniel

A1 Karlsson, Kim

T1 Simulation models of dual mass flywheels

YR 2017

AB Heavy duty trucks are faced with strict requirements regarding exhaust emissions and fuel eciency. The
demands are achieved through downsizing and downspeeding. This introduces torsional vibrations in the
powertrain which, if not dealt with, will decrease life and comfort. One solution that deals with these vibrations
is the Dual Mass Flywheel that absorbs the vibrations.
The goal of this thesis is to develop and verify different computational models of a Dual Mass Flywheel and in
particular study how the friction between the arc-spring and the primary
ywheel affects the system.
Modelling is done in Python using the Newmark- method combined with Newton's method for numerical
simulations. The same model is also created in AVL Excite for verification. The friction between the arc-spring
and the primary
flywheel channel is modelled using the Coulomb friction model or an inverse tangent function.
It has been verified that the two computational models give similar results.
A method to approximate Coulomb friction has been developed in order to make the computational model
more stable. The friction depends on both spring compression and centripetal force due to the rotation of the
Dual Mass Flywheel. For a truck's operating speed the spring compression is the largest factor to frictional
losses with current selection of geometrical and structural parameters. The results show that with low friction
and low viscous damping resonance is not a significant problem even if it occurs at low engine speed. A study
about the number of masses needed to solve the friction model have been performed. It is concluded that the
friction moment has not converged using five spring masses. A method of achieving accurate results with few
masses is presented.
For a final conclusion about the dynamics of the Dual Mass Flywheel, the developed computational models
need to be validated using experimental data. Modifications of geometrical and structural parameters should
be done to fit the experiments.
Keywords:Torsional Vibrations, Dual Mass Flywheel, Python, AVL Excite Timing Drive, Computational
Models

PB Institutionen för tillämpad mekanik, Dynamik, Chalmers tekniska högskola,PB Institutionen för tillämpad mekanik, Dynamik, Chalmers tekniska högskola,

T3 Diploma work - Department of Applied Mechanics, Chalmers University of Technology, Göteborg, Sweden, no: 2017:18

LA eng

LK http://publications.lib.chalmers.se/records/fulltext/250346/250346.pdf

OL 30