l'analisi multibody nell’industria automotive: adams/car

Paolo Gervasio

MSC.Software Project Manager

l'analisi multibody nell’industria automotive:Adams/Car

MSC.Software Project Manager

Mercoledì 30 aprile 2014

• ADAMS: Automatic Dynamic Analysis of Multibody System– Presentazione di Adams quale solutore di sistemi multicorpo, I diversi software della suite

Adams e la loro integrazione in Adams/Car.

• Adams/Car– Perché A/Car e sua struttura. Organizzazione dei dati e realizzazione dei modelli utente

mediante il sistema template->subsytem->assembly.

• Simulazioni con A/Car– Tipologie di simulazioni affrontabili con Adams/Car, peculiarità e ambito di applicazione.

Agenda

MSC Software Confidential

• Realizzazione di nuovi modelli– Il template builder e la creazione di modelli parametrici.

• SmartDriver– Il pilota di A/Car, dove interviene e suo utilizzo.

• Adams/Tire– Modelli di pneumatico disponibili in A/Car, cosa sapere per un uso corretto.

• Adams/Controls– Cosimulazione in ambiente Adams/Car

• Adams/Flex– Introduzione di corpi deformabili in un modello Adams.

Definizione di sistema Multi-Body

• Sistema di parti meccaniche rigide / flessibili

• Interconnesse da giunti rigidi / elastici

• Soggette a qualsiasi sistema di forze

• Compiono grandi spostamenti nello spazio 3D

Introduzione alla dinamica dei sistemi multi-body


•


Definizione di sistema Multi-Body

•Dinamica descritta da equazioni differenziali

•Vincoli descritti da equazioni algebriche

� Sistema di equazioni DAE non-lineare


� Sistema di equazioni DAE non-lineare

Risoluzione di tipo numerico

� Integratori ODE

(Ordinary Differential Equations)

� Integratori DAE

(Differential Algebraic Equations)


Basic Concepts


Basic Concepts


� Kinematics:

o Study of motion of a system without regard to motivating forces

o All degrees of freedom are prescribed as functions of time

o Forces cannot affect motion

o Forces calculated as a consequence of motion

o Displacement, Velocity, Acceleration and Reaction force solution is algebraic in nature

o No need to solve differential equations

� Statics:o Study of equilibria of a system without regard to inertia forces or velocity dependent forces


o Study of equilibria of a system without regard to inertia forces or velocity dependent forces

o System velocities and accelerations are zero at each configuration

o Force affects configuration only

o Governing equations are algebraic in nature

� Dynamics:

o Study of motion of a system as a consequence of applied forces and inertia forces

o Forces affect accelerations

o Accelerations are integrated to velocities

o Velocities are interated to give displacements

o 2nd order differential equations are to be solved

� Linear Analysis:o Study of the modes of vibration of a system at any specified operating point:

o Equations of motion are linearized about operating point to getare constant matrices

o Vibration mode shapes and frequencies are analyzed by solving the associated eigenvalue problem


ADAMSAutomated Dynamic Analysis of Mechanical System


GENERAL PURPOSE COMPUTER PROGRAM

Applicazioni dell’Analisi Multibody


Applicazioni dell’Analisi Multibody


ADAMS/ExchangeADAMS/Exchange

ADAMS Full SimulationADAMS/View(Pre/Post) & ADAMS/Solver

ADAMS/Controls ADAMS/Durability ADAMS/Flex ADAMS/Linear

ADAMS/Postprocessor

ADAMS/InsightADAMS/Insight

Test labEngine Advanced

Engineering

Suppliers

• Bridges departments by sharing models and data

• Facilitates quick subsystem changes

• Templates

Applicazioni dell’Analisi Multibody nella grande industria


DrivelineChassis

engineeringBody

engineering

Suppliers

Applicazioni dell’Analisi Multibody nella grande industria


ADAMS/ExchangeADAMS/Exchange

ADAMS Full SimulationADAMS/View(Pre/Post) & ADAMS/Solver

ADAMS/Controls ADAMS/Durability ADAMS/Flex ADAMS/Linear

ADAMS/Postprocessor

ADAMS/InsightADAMS/Insight

Adams/Car


Adams/Car: gerarchia dei modelli


• A database is a collection of tables (directories) stored on the hard drive. The top directory, which has the extension .cdb, stores a number of tables (directories). Each table is a placeholder for model information.

Adams/Car: organizzazione dei dati


Adams/Car: file di simulazione

Driver control data file (.dcd)

Event file (.xml)

Adams command file (.acf)

Adams dataset file

(.adm)

Adams/Car Interface


Adams/Car Solver

.msg

.req

.res

.gra

.out

Output files

Adams/Car: tipologie di simulazione


Adams/Car: Template builder


1. Calcola con un solutore quasistaticoun profilo di velocità coerente con la traiettoria e i limiti del veicolo

2. Il solutore interno (modello rigidosemplificato) verifica l’applicabilitàdella velocità richiesta in quel punto di

Adams/SmartDriver


della velocità richiesta in quel punto disimulazione e ne richiede la eventualecorrezione

3. Il veicolo viene risolto nelle condizionipreviste con il modello semplificato

Adams/Tire


Adams/Controls (Co-simulation)


• Function evaluation (or continuous) mode lets the MATLAB (or EASY5) integrators solve the entire problem made up of the Adams equations and the MATLAB (EASY5) equations. In this mode, Adams simply acts as a ‘function evaluator’ for the MATLAB (EASY5) integrator.

Adams/Controls (Function evaluation)


Mode Integrators used Comments

Co-simulation MATLAB and AdamsMATLAB solves Simulink model, Adams/Solver solves Adams model. Data exchanged periodically.

Function Evaluation MATLABMATLAB solves both, Simulink model and Adams model. Adams/Solver just acts as function evaluator for MATLAB integrator.

If you can satisfy these requirements:

1. MATLAB with a Real Time Workshop license available.

2. Microsoft Visual C++ for compilation in RTW. Other C/C++ compilers (for example gcc) will not work properly.

3. An available Adams/Controls license.

Adams/Controls (Control system import)


*.dll

• Adams will support the Functional Mock-up Interface (FMI) standard

Adams/Controls (FMI Co-simulation)


Adams/Flex: Component Mode Synthesis

free-free mode


static correction mode

Use Lagrangian Formulation:

Extended DOF table ξ

Rigid

Modal

Th

e F

lexib

le B

od

yAdams/Flex: Coupling Equation of Motion


5. Solve Equations

1. Compute position of point P in Global Ref.

up

≅ Σ Φi(P)qi2. Use Modal Expansion approximation for up

3. Derive w.r.t. time and compute vp

4. Compute Kinetic and Potential Energy for the FB

Th

e F

lexib

le B

od

y

Adams/Flex


MSC & University

• FEA Solver Used by Large Manufacturers

MSC Nastran Student Edition (with Patran)

• FEA Solver for Tough Nonlinear Problems

Marc Student Edition (with Mentat)

MSC Nastran-Patran

MSC Student Editions


• FEA Solver for Tough Nonlinear Problems

• Kinematic and Dynamic Analysis of Systems

Adams Student Edition (with View)

Marc-Mentat

Adams-View

• Powerful Acoustic Simulation Software

Actran Student Edition

Actran

Learning Resources for Teachers


• MSC Learning Center - $99 Subscription for Students

• Video Tutorials – Student Edition Tutorials

• Actran Student Edition Tutorials – Problem Sets

• SimCompanion – Knowledge Base Portal

Learning Resources for Students


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l'analisi multibody nell’industria automotive: adams/car

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