Raccolta casi Working Model, visualNastran & SimWise - Motorcycle's handling
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WITH WORKING MODEL 3D CODE
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Lorenzo Sangiorgi, a student of Prof. Cossalter at Padua University, Italy, has made use of Working Model 3D and Visual Basic to perform a full analysis of the motorcycle's handling.
Introduction
The aim of this project is to realize a model of a motorcycle using the multibody code Working Model 3D; we also try to introduce a model of the tyre as nearest as possible to reality.
In addition to aq motorcycle’s model, we have created a program using Visual Basic for calculating forces and torques acting on tyres in function of slip and roll angle and of all of the characteristic parameters related with the real behaviour of tyres.
The realization of motorcycle’s model
The model has been created by drawing the essential elements: the rear frame, the rear swing arm, the rear wheel and tyre, the front fork, the front wheel and tyre.
All these elements have been linked in a Working Model 3D file, using some of the constraints that this code put at user’s disposal.
For each tyre we can modify a lot of parameters, such as Pacejka constants, roll and drift hardness, radial hardness and damping, lenght of relaxation and much more.
The steer torque
The steer torque represents the rider’s action on steering-wheel in order to keep motorcycle’s balance and to cover the desired trajectory. The steer torque is calculated in function of the desired roll angle, through a proportional and derivative system.
The program Motobike
This program calculates forces and torques acting on tyres according to the theoretical model, "e;rides"e; the motorcycle through the steer torque and calculates the engine and the brake torque acting on wheels. For each tyre we can modify a lot of parameters, such as Pacejka constants, roll and drift hardness, radial hardness and damping, lenght of relaxation and much more.
Running test
As far as the model has been realized, we have carried out some tests with the
aim of the studying motorcycle’s manoeuvrability, analysing its variation when some
characteristics parameters are varied.
We have considered two tipical handlings:
The typical parameters of tyres, that have been modified during the various tests, are:
For each test we have studied the variations of motorcycle’s performance by analysing the graphs related to:
As an example, you can see some typical graphs obtained with one simulation:
Conclusion
The results we have obtained confirm the validity of the simulation model
because they agree with some experimental results and with the results of an
analytical programme.
We remark that our purpose was not that of improving the motorcycle used to
create the model, but we have pointed our efforts to create a model as nearest
as possible to the reality, in particular with regard to the tyre model, that
has been the real limit so far encountered in studying motorcycles by using
multibody codes.
The programme Motobyke, developed for this purpose, allows us to get over this
limit and, united with Working model 3D, is suitable to realize a virtual
prototype very close to reality.
Student: Lorenzo Sangiorgi
Professor: Prof. Vittore Cossalter, Università di Padova - Italia
Other applications at Padua University in Italy!
Three wheels vehicle simulation
Motorbike dynamical simulation
Tyre test bench
Suspension analysis for a motoscooter
Mechanical simulation course
Basic exercises for students
ALTRI 83 CASI IN SETTORI DIVERSI !
