Engineering Simulations and Testing by ATOAST

8/8/2019 Engineering Simulations and Testing by ATOAST

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ATOA Scientific TechnologiesEngineering Simulation For Innovation

Engineering Simulations and Testing

Raj C Thiagarajan, PhD

The Engineering process is the

conversion of material into useful

product. The need for both simulation

and experiments for reliable and

rapid development of new products is

outlined. This report provides a brief

overview of the simulation based

engineered product development and

testing for the first time right product

development. The interplay between

simulation and testing are highlighted.



© ATOA Scientific Technologies Engineering Simulation For Innovationwww.atoastech.com

Table of Contents

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1. The Engineering Process

2. The Simulation for the First time right

3. Simulation Based Engineering (SBE)

4. Simulation based Engineering Design (SBED)

5. Type of Failure and Examples

6. Reliability of Simulations

7. Testing of Materials

8. Why do we Test?

9. Simulation and Testing + Validation & Verification

10. What Material Properties are Tested?

11. What is Measured?12. Type of Mechanical Testing

13. Virtual Testing

14. The Four Stages of Complimentary Simulation and Testing




The Traditional Engineered Process

The Simulation Based Engineered Process

The Engineering Process

Mathematical

Computational

Design

Predictive

Processing

Testing for

Validation &

verification

Virtual

product/

system

Conceptual Design Fabrication Assembly Testing

Transformation of

Material into Useful Products

FIRST TI

ME RIGHT

ENGINEERING PROCESS PRODUCT MATERIAL

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The Simulation for the First time right

Real product/

system

Mathematical

model

Computational

model

Prediction(Output)

MATHEMATICAL MODEL

•Captures the THE PHYSICS EMBEDDED IN THE ENGINEERING SCIENCES

•Simple closed-form solutions to establish essential relationships, Numerical solutions for complexproblems

•Properties of different types of differential and integral equations

•Closed-form solutions only available for very simple problems

•The mathematical model only transforms the available information about the real problem into a

predictable quantity of interest

COMPUTATIONAL MODEL

•Computers have revolutionized techniques for solving differential and integral equations

•Finite element methods,

•Availability of Fast and cheap computing power

•Accurate numerical solutions to complex problems

•Nonlinearities easily handled

•The purpose of computation to model the real system to output the quantities of interest onwhich a decision can be made

• NEW PARADIGM: Simulation based engineering Design (SBED) with Multiphysics and Multiscale depth

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It is a must to incorporate all the known Scientific and or Engineering knowledge for a

given problem solving or new product design.

Failure by not integrating the known knowledge is not professionally acceptable.




Simulation Based Engineering (SBE)

•

Engineering is the profession in which aknowledge of the mathematical and naturalsciences gained by study experience, andpractice is applied with judgment to developways to utilize, economically, the materialsand forces of nature for the benefit of thesociety -Accreditation Board for Engineering and Technology

• SBE to develop Virtual Innovative Products for uniquecustomer experience with highest performance andreliability at lowest cost .

• Studies shows that the Simulation based Productdevelopment, reduced the prototyping by 50% andincreased the lead time ~60 days ahead of thecompetition.

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Simulation based Engineering Design

(SBED)• SBED provides unparalleled access to real-world

conditions• SBED is credited with numerous success story

• SBED can be used to Predict unknown productperformance for first time right

• Eventually can be used to predict the future outcome

• Simulations has none of the following limitations of experimental designs /tests,

– Cost constraints

– harsh/unrealistic parameter ranges, and

– Environment, Health and Safety concerns.

• It has become indispensable for – Weather prediction

– Medical diagnosis (Virtual human)

– Material modeling

– Drug synthesis

– Auto design for crashworthiness

From: Research Directions In Computational Mechanics, A Report of the United States NationalCommittee on Theoretical and Applied Mechanics, September 2000

Ref: Jaroslav Mackerle Finite-element analysis and simulation of machining: a bibliography (1976 –1996), Journal of Materials Processing Technology 86 (1999) 17 –44

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Type of Failure and Examples

A. Modeling Problem/ Unknown Phenomenon

The Tacoma Narrows Bridge. The suspension bridge across Puget-Sound(Washington State) collapsed November 7, 1940.

Reason: the model did not properly describe the aerodynamic forces and theeffects of the Von Karman vortices. In addition, the behavior of the cables wasnot correctly modeled.

• The Columbia Shuttle Accident June 2003. It was caused by a piece of foambroken off the fuel tank. After it was observed, the potential of the damagewas judged, upon computations, as nonserious. Reason: the model used did

not take properly into consideration the size of the foam debris.B. Numerical Treatment Problem

• The Sleipner Accident. The gravity base structure of Sleipner, an offshoreplatform made of reinforced concrete, sank during ballast test operation inGandsfjorden, Norway, August 23, 1991. Reason: finite element analysis gave a47% underestimation of the shear forces in the critical part of the basestructure.

C. Computer Science Problem

• Failure of the ARIANE 5 Rocket, June 1996. Reason: problem of computer

science, implementation of the round offs.D. Human Problem

• Mars Climate Orbiter. The Orbiter was lost September 23, 1999, in the MarsAtmosphere. Reason: unintended mixture of Imperial and metric units.

From: Babuška, F. Nobile, R. Tempone, Reliability of

Computational Science, Numerical Methods for Partial

Differential Equations, DOI 10.1002/num 20263,

www.interscience.wiley.com

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Simulations helps to avoid failure &

make it first time right.

http://upload.wikimedia.org/wikipedia/commons/4/42/Mars_Climate_Orbiter_during_tests.jpg

http://upload.wikimedia.org/wikipedia/en/2/2e/Image-Tacoma_Narrows_Bridge1.gif



Reliability of Simulations

Engineering accidents can happen due to,

– Modeling Error,

– the numerical treatment,

– computer science problems, and

– human errors.

Reliability of simulation depends on• The Mathematical model.

• Resources vs performance

• Deterministic/ Probabilistic

• Prediction/quantification

–Failure probability

– Confidence level/ Factor of safety

• Simulations are moving from Trend prediction toactual and accurate performance prediction

Objective is to increase the reliability of simulations.

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Testing of Materials

• Simulation and Testing are complimentary• Similar to Theory vs Experiments.

• Testing are generally used to verify simulations.

• Simulation also includes virtual material testing.

• Faster and cheaper new product Development

• Prediction of anisotropic, complex, costly and time

consuming experimental properties.

• Simulation helps to cut the cost and time

• But Final, limited Testing is a must for new product

Development and Introduction into the

Market.

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Why do we test?

•

Avoid Premature Failure• Testing is part of the engineering Process

• To augment Computational Simulation based

Engineering for Virtual product development .

• To provide inputs to simulation

• Validation and Verification

• Material, product, process, system development

• Characterization of Material properties

• Part performance prediction

• Quality control/assurance, Long term reliability

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Simulation and Testing + V&V

• The interplay between Simulation and Testing.

• Testing is a process to help validation and verification

for first time right.

• Validation is a process determining if the mathematical

model describes sufficiently well the reality

• Verification is a process of determining whether the

computational model and the implementation lead tothe prediction with sufficient accuracy.

• V&V concepts are applicable to all stages of testing….

Real product/

system

Mathematical

model

Computational

model

Prediction

(Output)

Validation Verification

Simulation

Testing

Reference: Leszek A. Dobrza´nski, Significance of materials science for the future development of societies, Journal of Materials Processing Technology 175 (2006) 133 –148

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What Material Properties are Tested?

Mechanical:

• Strength, stiffness, elasticity, plasticity,ductility, brittleness, hardness, wearresistance, Impact strength, fatigue life.

Thermal:

• Expansion, specific heat, thermalconductivity, Thermal diffusivity

Electrical & magnetic:

• Conductivity, permeability, permittivity,dielectric properties.

Acoustical:• Sound transmission, Attenuation.

Optical:

• light transmission/reflection, haze,absorption, Color.

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What is Measured?

• In a Typical mechanical testing:

• Force and pressure

• Deflection and displacement

• Hardness

•Velocity, acceleration,

• Temperature, humidity

• Variation due to 5M (People, Machine, Methods, Material,

Mother Nature).

• Specification, Quality control , Gauge R&R, Data transfer

• International standards (ASTM, ISO..) guide Testing Process

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Type of Mechanical testing

•

Load type : Tension, Compression, shear, torsion, flexure,• Loading rate/time/ Repetition :

Steady state/ Static/ Short

term/ Monotonic

Mechanics:

Fixed geometry, loads

Continuum

Dominated by final failure

events

Physics:

Equilibrium state

Constant properties

Transient/ dynamic/ Long term /

cyclic

Mechanics:

Variable geometry, loads

Discontinuous

Dominated by micro mechanical

events

Physics:

Variable state of material

Variable properties

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Only Mechanical testing is referred. Watch out this space for more on Thermal,

Electrical, Magnetic, Acoustical, Opticals...



Virtual Testing

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• Simulation to predict the experimental properties

of systems.

• For example, It is difficult to characterize all the

anisotropic properties of composites. Numerical

models is used to predict the complimentary

anisotropic properties.

• Simulation to mimic the testing is performed to

zoom into the inner working mechanism of

materials and products.

• The progressive growth, failure, damage mechanics

can help to reverse engineer the materials for

improved and optimal performance.

• Virtual Testing are used to simulate and predict

high risk and costly experimental tests for cost

effective product development.



Four Stages of Complimentary Simulation and

Testing for the Engineering Design of First Time

Right Product Development

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ATOA Scientific Technologies Pvt Ltd (LLC)

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ATOA Scientific Technologies is an engineering simulation

service provider, with a specialty on Multiphysics,

Multiscale and Multimaterials, for innovative material,

product, process and system development to cut cost

and cycle time for our clients.

MULTIPHYSICS ENGINEERING SIMULATIONS

Structural ↔ Thermal ↔ Flow ↔ Dynamics ↔ Acoustics ↔ Optics

Contact:

[email protected]

For all your Engineering CAD, CAE, CFD, CAPD, CAI Needs.

Engineering Simulations and Testing by ATOAST

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