String model (1)
The string model is herein used to explain the essentials of transient tyre
force generation. In this development rolling resistance is neglected,
complete adhesion is assumed, and all deformations are treated as small.
As a consequence t
Moving Bodies
1) Modify Body (right click on tree)
Modelling and Simulations of Mechanical Systems A/A 2015/16
Universit degli Studi di Padova  Prof. M. Massaro
2) Move Tools (from toolbar)
6
Moving Bodies (cont.)
3) Precision Move (Edit/Move)
4) Tools/
Starting points for simulation
(Time domain) Simulations are usually started from one of two following
conditions:
consistent set of position and velocity coordinates;
equilibrium coordinates set.
Modelling and Simulations of Mechanical Systems A/A 2015
Optimization
A/A 2015/16
Prof. M. Massaro
Universit degli Studi di Padova
Basics
Optimization consists in finding parameters that minimize (or
maximize) objectives while satisfying constraints (best performance).
The process consists in
Modelling the (mu
Tyres
A/A 2015/16
Prof. M. Massaro
Universit degli Studi di Padova
Background (1)
Roadtyre interactions were modelled classically using two nonholonomic constraints (pure rolling), which is a reasonable approximation
at very low speeds only.
At the end
Dynamics
A/A 2015/16
Prof. M. Massaro
Universit degli Studi di Padova
Background
The equations of motion of a mechanical system can be derived using
vectorial mechanics, or variational techniques (analytical mechanics).
Vectorial mechanics is based on for
Exporting from CAD to Adams
Recommended format for exporting CAD data so that they can be
imported effectively in Adams:
Unigraphics, Solidworks, SolidEdge: parasolids (*.x_t)
Catia: stereolithography (*.stl)
Pro/Engineer or Creo: render (e.g. *.slp)
N
Method 3: stiff differential equations
The algebraic equations can be considered a special form of differential
equations, whose dynamics are so fast that the related (differential) terms
can be neglected (e.g. + = becomes = when 1).
Definition 1 (popula
ADAMS basics
A/A 2015/16
Prof. M. Massaro
Universit degli Studi di Padova
How to download Adams Student Edition
http:/www.mscsoftware.com/it/page/adamsstudentedition
Click on Download Now and follow the procedure to get and install the
software (note th
Linear Systems
A/A 2015/16
Prof. M. Massaro
Universit degli Studi di Padova
Linear systems (1)
In many nonlinear problems, linearized models provide a satisfactory
approximate solution for the local dynamics.
Start with a nonlinear DAE model (dependent co
Generalized forces
The icomponent of the generalized force related to the force F acting on a
cfw_

point P attached to the frame zcfw_ , where cfw_~ =zcfw_ ~ , is = 0
1
1
c 
~ .
where =
c
1
0
The icomponent of the generalized force related
Kinematics
A/A 2015/16
Prof. M. Massaro
Universit degli Studi di Padova
Degrees of freedom
Degrees of freedom (DOF): minimum number of parameters necessary and
sufficient for a unique characterization of the configuration of the system.
Our systems consis
MBSymba
A Maple library developed at the University of Padova for symbolic
multibody modelling;
Among the other things, it can be used to create frames, points, vectors,
to manipulate them, to compute velocities, angular velocities, etc.;
Available fro