This presentation is the property of its rightful owner.
1 / 15

# Modeling and Simulation in Engineering PowerPoint PPT Presentation

Modeling and Simulation in Engineering. Chris Paredis G.W. Woodruff School of Mechanical Engineering Georgia Institute of Technology. Lecture Overview. Objective: Define what a model is Illustrate why models are important in engineering Topics: What is a model?

Modeling and Simulation in Engineering

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

## Modeling and Simulationin Engineering

Chris Paredis

G.W. Woodruff School of Mechanical Engineering

Georgia Institute of Technology

### Lecture Overview

• Objective:

• Define what a model is

• Illustrate why models are important in engineering

• Topics:

• What is a model?

• What are some properties of models?

• How does one create a new model?

• How are models used in engineering?

### What is a Model?

• Examples of Models…

• What do these examples have in common?

Noise, Vibration,

and Harshness

Thermal

Crash Testing

### Examples of Models in Vehicle Design

Computational Fluid Dynamics

Stress Analysis

All models are 'wrong'.

Some are useful.

Attributed to George Box

### What is a Model?

• Definition (based on Marvin Minsky's definition) :

• A model (M) for a system (S) and an experiment (E) is anything to which E can be applied in order to answer questions about S

• A model is an abstraction of reality

Who has created a new model today?

### How Do We Create Models?

• Gather data about real system

• Postulate hypotheses about the relationships in the data

• Formalize these hypotheses in models

• Validate models by performing simulations

• If necessary, modify the hypotheses and models until valid

Models can never be proven correct – only falsified.

### A Quick Aside:When is a Model Valid?

Is this model valid?

f(x)

x

### Unanticipated Phenomena May Invalidate Model

Tacoma Narrows Bridge,

Nov 7, 1940.

Simulator

Simulator

Simulator

Simulator

System

Model

System

Model

System

Model

System

Model

### Why are Models Important in Engineering?

Initial

Guess

Satisficing

Solution

Decision

Solver

Predict theOutcome of Engineering Design Decisions

DesignAlternative

Evaluation ofDesign Alternative

### When are Models Most Useful?

• When the system is not available

• When the physical experiments cannot be performed

• When the cost of experimentation is too high

• When the time scale of the system is not compatible with those of the experimenter

• Under controlled circumstance (e.g. no disturbances)

Noise, Vibration,

and Harshness

Thermal

Crash Testing

### Examples of Models in Engineering

Computational Fluid Dynamics

Stress Analysis

### Manufacturing Simulation

• DFM – DFA – DFX

• Take life cycle cost into account at the design stage

### Training Simulators

• Use the previously developed simulation models for training

• Train operators before prototypes are built

• Test whether user interface is user-friendly

### Immersive Environments

• Allow user to interact with models through

• 3-dimensional vision

• Touch (tactile interface)

• Complete virtual prototype

Crash Testing

### If a picture is worth 1000 words,how about a simulation?

Summary

• We all create and use models all the time

• Models should be validated

• In engineering, models are used for predicting the outcome of decisions, but also for training or documentation.

• In this class you will use models to solve engineering problems