Dr. G. Valter Diurno

nothingstockingsMechanics

Oct 30, 2013 (3 years and 7 months ago)

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Dr. G.
Valter

Diurno

Technical Director CAE

Power Resources International

31 Nancy Street

W. Babylon, NY 11704

www.priinc
-
cae.com

PRI


CAE

Power Resources International


Computer Aided Engineering


Company active in the area of Industrial Automation for
two decades

New area of business and interest Computer Science and
Engineering:


Computer Aided Engineering


partnership with
SIEMENS PLM
and
Simpleware


Consulting services in Computational Fluid Dynamics,
Heat Transfer and Stress Analysis


Software Development, System Integration


Copyright @PRI
-

Power Resources International
-

31 Nancy Street , W. Babylon, NY
-

USA
-

www.priinc
-
cae.com

… who am I ?


Aerospace Engineering background, research and development of
numerical methods and models for FEM and FVM in hypersonic
and supersonics flows


CFD (Computational Fluid Dynamics) Software Development
industry: Turbulence modeling, Mesh generation, Heat Transfer


Mechanical Engineering, Consulting services, Software development



Research: CIRA (Italian Aerospace Research Center), University of
Naples, Italy


European Space Agency, University of Maryland, College
Park, MD


CD
-
Adapco
, Software Development FEM, FVM, Meshing


Whirlpool


CAE applications and simulations


PRI
-

Design and development of advanced enterprise client/server
automation command and control systems


Technical Director of CAE

Copyright @PRI
-

Power Resources International
-

31 Nancy Street , W. Babylon, NY
-

USA
-

www.priinc
-
cae.com

Composite Materials

Historical perspectives


before industrialization


the

development

of

composite

materials

and

related

design

and

manufacturing

technologies

is

one

of

the

most

important

advances

in

the

history

of

materials




Natural

Composite

Materials
:

Granite

example

of

perfect

composite,

fine

grain

“Groundmass”

with

dispersed

phase

of

crystals

rocks,

lacking

the

modern

features

of

a

composite

material

(strength/weight

ratio)
.

Wood

perfect

example

of

natural

laminate

composite,

easy

to

use,

lightweight

(used

in

the

early

stages

or

aeronautics)



Artificial

Composite

Materials
:


Babylon,

Mesopotamia
:

fiber

reinforced

bricks,

aggregates

of

bitumen

(early

use

of

petrol

products)

Ancient

Egypt
,

different

kind

of

stones,

granite
.

Use

of

materials

in

layers
.


Roman

Empire
,

different

kind

of

stones,

roads

realized

with

layers

of

materials,

concrete,

reinforced

concrete

with

stones,

metals,

glass,

plywood,

metals

alloys

(bronze,

brass,

lead,

aluminum,

steel

etc
.
)
.

Large

structures

still

surviving

the

centuries
.


Europe

Middle

Age,

Renaissance
:

iron

reinforced

stones,

concrete,

wood,

different

metal

based

alloys

(aluminum,

copper,

iron,

manganese,

etc
.
)
.

Ceramics

and

glass
-
based

materials

for

fine

arts,

construction

and

engineering








Copyright @PRI
-

Power Resources International
-

31 Nancy Street , W. Babylon, NY
-

USA
-

www.priinc
-
cae.com

Composite Materials

High strength/weight ratio, easy to use, low radius of
curvature thin structures, cost effective, durable,
resistant etc.

No standard definition, but in general:

4 categories
:
polymers
,
metals
,
ceramics

and
carbon

4 types:
PMC

(Polymer matrix composites)




MMC
(Metal Matrix composites)


CMC
(Ceramic Matrix composites)





CCC
(Carbon / Carbon composites)


Copyright @PRI
-

Power Resources International
-

31 Nancy Street , W. Babylon, NY
-

USA
-

www.priinc
-
cae.com

Composite Materials

characterization

Material with two or more physically distinct phases

Continuous phase:
Matrix

Distributed phase:
Reinforcement


Particle reinforced composite


Short fiber or whisker reinforced composites


Continuous fiber or sheet reinforced


Laminate composites

Copyright @PRI
-

Power Resources International
-

31 Nancy Street , W. Babylon, NY
-

USA
-

www.priinc
-
cae.com

Composite Materials

Physical Characteristics



Strongly heterogeneous materials


Anisotropic


Some fiber
-
reinforced composites do not have plastic
behaviors as metals (more sensitive to stress
concentration, but not necessarily more brittle)


Complex failure dynamics


Physical characteristics strongly dependent from
the production process



Copyright @PRI
-

Power Resources International
-

31 Nancy Street , W. Babylon, NY
-

USA
-

www.priinc
-
cae.com

Computational Challenges

in modern engineering


Costs

constraints

in

competitive

markets

require

fast

reactions,

short

idea
-
to
-
market,

quality

and

regulations

fulfillment,

often

there

is

no

time

or

resources

to

build

series

of

prototypes


Extrapolation

of

experimental

results

cannot

address

all

the

needs

of

design



Complex geometries, require numerical simulation
tools to help design and verify “what if “ scenarios
difficult or impossible to calculate with analytical
methods or to simulate with experimental methods



Copyright @PRI
-

Power Resources International
-

31 Nancy Street , W. Babylon, NY
-

USA
-

www.priinc
-
cae.com

Computer Aided Engineering


Combination

of

computer

codes

to

provide

engineers

a

framework

for

design

and

verification

of

new

products,

optimization

or

modification

or

existing

products

,

realization

of

virtual

experiments

for

research,

development,

verification

of

functionalities,

fulfillment

of

regulations

or

fundamental

physics

studies
.



FEA


Finite Elements Analysis
-

numerical simulation technique


FE, mathematical approach to
solve PDEs


Mostly used for Solid Mechanics
and Heat Transfer


Many other technologies … FVM,
FDM, SPH, IB, Vortex Methods,
etc. used in Fluid Mechanics




Stress

Analysis
,

verification

of

the

material

resistance

under

a

system

of

forces


Computational

Fluid

Dynamics

and

Heat

Transfer
,

quantitative

and

qualitative

behavior

of

fluid

flows,

temperatures

and

heat

fluxes

around

and

inside

solids



Multi
-
physics
:

combination

of

solid/fluid/heat

transfer

for

complex

problem

involving
:

phase

change

(solid/liquid,

liquid/gas),

chemical

reactions

(combustion,

hypersonic

flows,

rockets,

turbomachinery
),

radiation

(s
0
lar,

thermal,

space

applications),

acoustics

,

microgravity,

etc
.


From

CAD

to

CAE



Geometry

“clean

up”,

Mesh

Generation

(equations

must

be

solved

in

discrete

form)

Copyright @PRI
-

Power Resources International
-

31 Nancy Street , W. Babylon, NY
-

USA
-

www.priinc
-
cae.com

Computational Challenges for
composite materials


monolithic materials are usually treated using classic elastic or
plastic theories


Isotropic common materials: linear relationship between the
stress and strain tensor


For more complex material such as fluids, gas, plasmas, non
-
Newtonian fluids,
elasto
-
plastic materials stress and strain
tensors or force
-
deformation relationship are expressed in a
different way (stress/rate of strain, non
-
linear relationship)


Composite materials can be still treated in the boundaries of
classic solid mechanics but they present specific anisotropy
characteristics that require special attention


Numerical

analysis

is

very

useful

not

only

in

the

application

stages

but

also

in

manufacturing

an

design

of

composite

materials

Copyright @PRI
-

Power Resources International
-

31 Nancy Street , W. Babylon, NY
-

USA
-

www.priinc
-
cae.com

Laminate Composites


Layers of materials stack one on top each other


Layers can have different or the same materials with
different fiber orientation


Failure analysis for a Laminate Composites are based
on “First ply failure theories” such as


Maximum stress or strain (non
-
interactive failure
criteria)


Hill


Hoffman


Tsai
-
Wu (interactive failure criteria)





Copyright @PRI
-

Power Resources International
-

31 Nancy Street , W. Babylon, NY
-

USA
-

www.priinc
-
cae.com

Failure based on Classic Lamination Theory


Similarly to “von
Mises
” yield criterion for metal failure,
theories are trying to obtain a single failure index to
indicate ply failure


In reality a ply failure in one direction may not produce
failure in another direction:
LaRC

and Puck theories
separate failure mechanisms


Progressive Ply Failure Analysis is trying to address the
limitation of the CLT. More computational expensive,
requires non
-
linear or transient analysis since it is based on
recalculation of stiffness matrix for each iteration


Useful
to simulate impact effects over composite structures

Copyright @PRI
-

Power Resources International
-

31 Nancy Street , W. Babylon, NY
-

USA
-

www.priinc
-
cae.com

Composites Materials

Design and Manufacturing issues


Manufacturing processes of composites strongly
affects the physical characteristics of the material


Microstructures and voids are difficult to analyze using
traditional experimental approaches


Micro CT
-
scans or similar techniques is a viable way to
understand the microscopic patterns in a composite
material


Numerical

Simulations

can

be

helpful

in

the

analysis

of

microstructures

(
3
D

models

from

images)

and

to

develop

computational

models

to

help

in

the

design

of

new

composites


Copyright @PRI
-

Power Resources International
-

31 Nancy Street , W. Babylon, NY
-

USA
-

www.priinc
-
cae.com

FEA


Finite Element Analysis


Physical systems or phenomena are often described by
Partial Differential equations or systems of
PDAs


FEM is a numerical technique to solve PDA on general
computational domains (space/time)


Process:


CAD or data: geometrical descriptions of objects and domains


“Clean up” CAD Geometry to provide a bounded well defined
domain


Meshing, subdivide the domain to fulfill mathematical,
numerical and resolution requirements for the equations to
be solved in discrete form


Boundary Conditions (Constraints and Loads)


Solutions of the system of equations /
bc


Analysis of the results

Copyright @PRI
-

Power Resources International
-

31 Nancy Street , W. Babylon, NY
-

USA
-

www.priinc
-
cae.com

Computational Tools Available


Design tools


CAD , 3D modeling tools


Meshing


CAD geometry “clean
-
up”, and Mesh Generation


3D modeling and meshing from images (micro CT
-
scans)


Solvers


FEA , FVM, etc.


New elements / models for composites


Postprocessing


Efficient and fast 3D visualization and reporting

Copyright @PRI
-

Power Resources International
-

31 Nancy Street , W. Babylon, NY
-

USA
-

www.priinc
-
cae.com

Computational Tools



Siemens PLM

Solid Edge and FEMAP


Siemens PLM

NX integrated framework for design
and analysis


Siemens PLM
NX

Nastran

solid mechanics solver


Simpleware

SCANIP+FE , 3D models and meshes from
images



Copyright @PRI
-

Power Resources International
-

31 Nancy Street , W. Babylon, NY
-

USA
-

www.priinc
-
cae.com

Complete Multi
-
Discipline Analysis

A Single Environment For All Mechanical Tools

Copyright @PRI
-

Power Resources International
-

31 Nancy Street , W. Babylon, NY
-

USA
-

www.priinc
-
cae.com

NX 8 Simulations

NX 8 CAE


Pre/post & geometry foundation


Multi
-
discipline simulation and optimization


Systems
-
level simulation


HD
-
PLM


Compatible with all the major CAD/CAE

(CATIA,
SolidWorks
, ABAQUS, ANSYS, etc.)




NX Nastran 8


Discipline and physical domain extensions


Computational performance and numerical accuracy


Ease of modeling and engineering workflow


Compatible with all the major CAD/CAE

(CATIA,
SolidWorks
, ABAQUS, ANSYS, etc.)


Copyright @PRI
-

Power Resources International
-

31 Nancy Street , W. Babylon, NY
-

USA
-

www.priinc
-
cae.com

NX


Laminate Composites

Copyright @PRI
-

Power Resources International
-

31 Nancy Street , W. Babylon, NY
-

USA
-

www.priinc
-
cae.com

Multi
-
physics and multi
-
discipline
analysis

Copyright @PRI
-

Power Resources International
-

31 Nancy Street , W. Babylon, NY
-

USA
-

www.priinc
-
cae.com


Simpleware : Converting 3D
Images into Numerical
Models



converting 3d images into numerical models

Target markets &
applications

Medical & Dental

Materials & Geology
Natural
Sciences



Biomechanics &
Orthopaedics



Implant Design



Physiological Flows



Consumer Products



Cell Mechanics




Oil & Gas



Non
-
destructive
Evaluation



Composite Analysis



Material
Characterisation



Pore Scale Fluid Flow



Palaeontology



Archaeology



Functional
Morphology



Food Sciences



Pollination

Copyright @PRI
-

Power Resources International
-

31 Nancy Street , W. Babylon, NY
-

USA
-

www.priinc
-
cae.com

+
FE module Automatic FE/CFD mesh generation

Material characterisation of
composite

converting 3d images into numerical models

MicroCT

scan of Al
-
TiB2
-
Fe
alloy

Segmentation

Iso
-
surface constrained to run
through segmented masks

Multi
-
part mesh generation

Merged/contact surfaces at part
interfaces

Each part based on signal
strength

Morphological accuracy image
limited

(Sub
Voxel

accuracy)

Scan to mesh in < 10 minutes

Material characterisation of
composite

In collaboration with:

Imperial College London

Material characterisation of
composite

Non Destructive Evaluation

converting 3d images into numerical models

MicroCT

scan of ceramic
matrix composite (CMC)

Holes clearly visible in the scan


Segmentation and mesh
generation

Details of holes


FE analysis in
ABAQUS,
Ansys

or NX
-
Nastran

Stress risers in the composite are
located at expected sites such as
porosities and voids locations

Non

Destructive Testing
(
NDT)

In collaboration with:

NASA Glenn Research Center

Conclusions

Use of composites

Design

and

verification

of

products

made

of

laminate

composites

reinforced

matrix

composites

or

monolithic

materials

using

advanced

verification

theories

using

advanced

tools




Design

of

new

composites

using

analysis

tools

based

on

microscopy

image

and

advanced

techniques

to

create

3
D

models

and

meshes

from

CT

scans

or

similar

techniques

Copyright @PRI
-

Power Resources International
-

31 Nancy Street , W. Babylon, NY
-

USA
-

www.priinc
-
cae.com

References


A. Sreeranganathan
(1)
, A.M. Gokhale
(2)
, P. Young
(3)

“Realistic micromechanical
modeling of discontinuously reinforced composites”
, Computational Materials
Science, 49 (2010), 407
-
413


I.G. Watson
(4)
, P.D. Lee, R.J
(4.1)
. Dashwood
(4.2)
, P.Young
(3)

“Simulation of the
Mechanical Property of an Aluminum Composite using X
-
ray
Microtomography

,
Metallurgical and Materials Transactions, Vol. 37A March 2006


551


A. Abdul
-
Aziz
(5)


Integrating NDT with Computational Methods such as Finite
Element
”, Materials Evaluation/January 2008


(1)
Stress Engineering Services Metairie, LA, USA

(2)
School of Material Science & Engineering, Georgia Institute of Technology, Atlanta, GA, USA

(3)
School of Engineering, Computing and Mathematics, University of Exeter, UK


also
Simpleware
,
Exeter, UK

(4)
Doctoral Student, (4.1) Professor (4.2) Senior Lecturer, Dept. of Materials, Imperial College, London,
UK

(5)
NASA Glenn Research Center, Cleveland OH