FEA in Practice 400

8/3/2019 FEA in Practice 400

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Finite Element Anal sis in

Practice


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Introduction


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Overview

This course is taught with a mix of

eore ca n orma on an app efinite element analysis (FEA).

oncep s are us ra e w s mp e,

hands-on exercises.Models are created which illustrate a

broad range of topics including

theory, element types, analysistypes, meshing techniques, results

evaluation and more.


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What is FEA?

FEA is a mathematical

so u on o eng neer ngproblems where a physical

model is divided into

discrete com onents.

FEA models are defined by

(commonly called a mesh).


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What is FEA?

Predicts change within the

e emen e.g., e orma on,stress).

The results are plotted on

the lowest and highest

.


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Why Use FEA?

Provides a non-destructive

means o es ng pro uc s.Faster rotot in for

what if scenarios.

.

Speed up time to market byshortening the designc cle.


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Best Practices

FEA requires engineering judgment. In

approximate answer before you begin.

, ,

loads, constraints and analysis

.


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Best Practices

Understand that the computer

only an approximation).

to underestimate the complexity of

.


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FEA in Different Industries

Aerospace Industry

The above illustration shows how engineersanalyzed a Biomass Production System tocon uc o ec no ogy p an researc .


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Automotive Industry

,Enprotech Mechanical Services, Inc.

a power press with additional cutouts.


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Ophthalmic Consultants of Boston and theTufts Universit School of Medicine

The above illustration shows stresses on an eye as itunderwent a 30saccadic eye movement. This was

occur.


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Power/Utility Industry

Cronulla Sewage Treatment Plant

The above illustration shows how engineers modeled apiping system to verify that the number of bellows couldsafel be reduced b usin li htwei ht s iral woundstainless steel. This allowed them to keep a $90 million

sewage treatment plant upgrade on budget.


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FEA verview


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The Basic Steps of FEA

Build/Mesh a Model

Define FEA Model

Analysis and Element Types

Define Loads and Constraints

Analyze Model (Solve)

Review Results and Create Presentations


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Example Using ALGOR

Create Mesh in CAD Solid Model or FEA Editor

Setup Analysis Type, Element Type and

Environment

FE

Materials in the FEA Editor Environment

Apply Loads and Constraints in the FEA Editor

M

P

Analyze Model (Solve)O

Review Results in the Results Environment

and Create an HTML Report in the Report

Environment


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FEMPRO Interface

A. Title bar

B. Menu bar

C. Toolbars

D. Tree view

E. Working area

F. Miniaxis

.

toolbar

H. Status bar


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Create Mesh

o o e

Environment

or

Environment

models from CAD

solid modelers or

- -meshes from

sketches.

universal files. Add lines to existing

meshes.


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Assign FEA Parameters

FEA Editor EnvironmentAssign element types and parameters.Assign material properties.

Apply loads and constraints.Assign analysis parameters.Analyze the model.


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Review Results

esu s nv ronmen

Review the model setup.

.Create images or animations of results.


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Present Results

epor nv ronmen

Generate a report of the analysis for presentation.

Add images or animations in an appendix.View summary and log files from the analysis.


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Introduction Example


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Opening the Model

Select File:O en....

Change the filet e to IGES *.i s

*.iges).

MotorMount.IGS.


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Applying the Materials

Select all three partsby clicking on the

part names in thetree view while

o ng own e

key.

g c c on e

name and select

Materials....

-

A36) from the list.


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Applying the Loads

Use the surfaceselection option.

Select the two topsurfaces of thebrackets.

After the surfaces areselected, right clickand select Add:

Pressure/Tractions....

psi.


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Applying the Constraints

Select the surfacesin the holes of the

shaft. After the surfaces

are selected, right

click and select: ur ace

Boundary

... .

Press the Fixed

OK button.


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Reviewing the Results

Run the analysis byselecting Analysis:

Perform Analysis.... Once the analysis is

complete, the von

Mises stress resultsw appear.


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Creating a Report

Select the Reporttab at the bottom of

the screen. Select the HTML

Report heading.

Right click andselect the ReportWizard command.

s w a e youthrough a five-step

an HTML report.


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Presentation of Results

Refer to the Presentation of Results

u or a ava a e a

www.algor.com/service_support/tutorialsfor more information on generating

reports.


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FEA Concepts


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What is a DOF?

The unknowns in a finite element problemare referred to as degrees of freedom (DOF).

Degrees of freedom vary by element andanalysis type.

StructuralForceDisplacement

ApplicationActionDOF Type

ThermalHeat FlowRate

Temperature


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What is a DOF?

Uy

Rot y

NodeRot x

Ux

UzRot z


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Node

in space where the DOF aree ne . e o s po n

represent the possible responseat this point due to the loading of

the structure.


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Element

relation that defines how theo a no e re a e o e

next. These elements can belines (beams), areas

2-D or 3-D lates or solids

(bricks and tetrahedrals).


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Nodes and Elements

A node has a given set of DOF, whichcharacterize the res onse. For structural

analyses, these DOF include translationsand rotations in the three global directions.

The type of element being used will also

characterize which t e of DOF a node willhave.

Some anal sis t es have onl one DOF at a

node. Examples of these analysis types aretemperature in a heat transfer analysis and

velocity in a fluid flow analysis.


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Element Connectivity

Elements can onl transfer loads to

one another via common nodes.

No Communication

Between the Elements

Communication

Between the Elements


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Stress and Strain Review

The basic stress and strain equations:

F

= A

= E

= FLE = 0

L dx


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Stress

Basic equations do not require the use of a.

Computer-based analysis is needed when

Geometric complexity makes the elasticity

e uation difficult or im ossible to solve.Variations in material properties exist throughout

the part.

Multiple load cases and complex or combinedloading exists.

.


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General Case

The DOF components of each element

=

[K] = element stiffness components=

{A} = action value (e.g., force, temperature)


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Structural FEA Equation

To determine the displacement ofa simple linear spring under load,

the relevant equation is:

{f} = [K] {d}Known Unknown

where {f} = force vector[K] = stiffness matrix{d} = displacement vector


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C l l ti f d


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Calculation of and

Strains are computed based on

the classical differentialequations previously discussed.

Stress can then be obtained

law (F = kx).

D i E ti


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Dynamic Equation

For a more complex analysis, moreterms are needed. This is true in adynamic analysis, which is defined bythe following equation:

{f} = [K] {d} + [c] {v} + [m] {a}

where {f} = force vector[K] = stiffness matrix

{d} = displacement vector

{v} = velocity vector

[m] = mass matrix

{a} = acceleration vector

Oth A li ti


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Other Applications

FEA can be applied to a wide varietyof a lications such as:

DynamicsNonlinear MaterialsHeat TransferFluid FlowElectrostaticsPiping Design and Analysis


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Element 1


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Element 1

2 0000

L

( )( ) =101021030 6x

k

1

1010

F

Element 2


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Element 2

5.05.05.05.0

3

( )

=

5.05.05.05.0

5.05.05.05.0

5.05.05.05.0

2x120

210x30k

6

1

F

Element 3


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Element 3

0101

F

1( )( )

=

0101

0000

120

21030 6xk

0000

Total Stiffness Matrix


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Total Stiffness Matrix

00354.0354.010354.1354.0

....

( )

=

00354.0354.000354.0354.0

00001010000,500k

01000001

00354.0354.000354.0354.0

00000000

Force and Displacement Vectors


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Force and Displacement Vectors

0 D

000,10

1y

x

D

=

y

x

F

F

2

=

0

D

y

x

F3

3

0

y

x

F4

4

0

0

Displacement and Stress Results


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Displacement and Stress Results

=nxx1 .=

inxD

2

1 1059.1

=

psi14712 =

3

ALGOR Model


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ALGOR Model

ALGOR Results


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ALGOR Results

inxD x2

1 10414.0=2

1

psi14642

=y1 . ps3 =


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Analysis Options

Choosing an Analysis Type


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g y yp

The first decision in the FEA processis to decide what type of analysis

you need to run.

The analysis type will dictate what

t e of results ou will obtain.For example, if you need the

will need to run a structural analysis.

Analysis Options


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y p

Linear Electrostatic

Linear dynamics

Fatigue

Current and voltage

Field strength and voltage Multi h sics

Nonlinear Nonlinear static

MES

Steady coupled fluid flow andthermal

Thermal Steady-state heat transfer

Analysis

Fluid Flow Steady fluid flow Unsteady fluid flow Flow through porous media

Structural


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Small changes in stiffness.No changes in loading

direction.Material remains in the linear

elastic ran e.

Small deformation and strain.

Structural


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Linear dynamics

a ura requency mo a

Response spectrumRandom vibrationFrequency responseTransient stress (direct integration)Transient stress (modal superposition)

Critical buckling loadDynamic Design Analysis Method(DDAM)

Structural


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Fatigue

.

Stress-based fatigue life calculation.- .

Structural


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Nonlinear/MESnear an non near ma er a mo e s.

Large deformation and strain.Failure due to:

Material yielding.

Local and structural buckling.

Permanent deformation -

residual stress.Large-scale motion.

Structural


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Nonlinear/MESur ace- o-sur ace con ac

ImpactCreep

Thermal


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ea y-s a e ea rans er

-

Transient heat transfer

Time-varying conditions

Fluid Flow


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Unsteady fluid flow

Flow through porous media

Electrostatic


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Electrostatic field strength andvo age


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Element O tions

Choosing an Element Type


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will depend on the following:Analysis type selected.

How ou create our mesh.Assumptions you can make.

Element Categories


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Line Elements: A line connecting 2nodes (beams, trusses, springs,

actuators, pipes, etc.)

Area (2-D) Elements: A cross-section

of a art. Must be 3 or 4 linesenclosing an area.

Element Categories


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Area (3-D Planar) Elements:Midplane of a part in space. Must

be 3 or 4 lines enclosing an area.

3-D Solid Elements: Must be 4, 5, 6

or 8 nodes enclosin a volume.


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Meshing and

Proper Modeling Techniques


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For any region (3, 4, 5, 6 or 8-nodes)to be a valid element, it must:

Consist of either three (triangular) orfour (quadrilateral) undivided line

segments. If a side consists of multiple

, .

Not have curved or arched sides.



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Certain shapes can create elementswhich are not recommended for FEA

analysis. The following regions will

be eliminated:

Re ions with an collinear orconcave sides.

Re ions with a hi hl nonflat

curvature in a 3-D drawing.



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Meshing Guidelines


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Meshing can be completed either byusing automatic mesh engines or by

creating a mesh by hand.

Automatic mesh generation is usually

com leted on CAD solid models.Hand meshing is usually done on

structured mesh.

Hand Meshing


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There are two types of hand meshing:building from scratch and building from a

wireframe.

Building from scratch:

Draw the elements by hand one at a time tocreate a structured mesh.

Building from a wireframe:

Build a 2-D or 3-D wireframe of the modelan use an uns ruc ure mes eng ne o

generate the internal elements.


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Loads and

Introduction to Loads and Constraints


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You will have to decide what type ofloads and constraints will properly

define the engineering criteria for themo e .

In FEA, there are different types of loads

. Applying the proper loads and

factors in getting the correct answer.

.

Types of Loads and Constraints


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There are multiple ways toapply different loads and

constraints to a model:

Nodal

Surface

Element

Structural Nodal Loads


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Displacements

Forces

Temperatures (thermal stress)

Voltages (piezoelectric materials)

Structural Nodal Constraints


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Boundary Conditions:Prevent specified DOF from

undergoing translation or

rotation in a specified

direction.Boundary Elements: Act like

stiffness along a specified



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Using Boundary Conditions to

Along the line of symmetry, boundary

the symmetrical part:

Out-of-plane displacement = 0

wo n-p ane ro a ons =



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P P P

Line ofSymmetry

P ane o Symmetry

Boundary Conditions


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Proper boundary conditions are

The global stiffness of the system must

behavior to be captured correctly.

Boundary Conditions


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The two most unwanted FEA effects to

Overstiffening

Unlike the real-world equivalent,

.

Linear Surface Loads


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Uniform or Hydrostatic Pressureand Traction

Applied to the face of plate, composite

and brick elements.

Applied to the edge of 2-D and

.

Surface Force

a force that will be evenly distributedover a given surface.

Linear Surface Loads


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Variable Pressure or Traction Define a function of the position that

controls the magnitude of the load over.

LinearElement Loads


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Gravit

Can specify gravitational value and

direction. You must have a mass densitye ne or eac par .

Centrifugal Loads

,and acceleration values.

Specify the magnitude and direction ateach end of beam elements.


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Truss Elements

Truss Elements


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Truss elements are two-node,

orientation in the X, Y, Z

system.

The truss transmits axial forceonly, and in general, is a three

e emen .e., ree g o atranslation components at each

end of the member . Trusses

are used to model structuressuch as towers, bridges and

u ngs.

Truss Elements


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Guidelines for usingruss e emen s:

The length of the element is muchgreater than the width or depth

(approximately 8-10 times).

It is connected to the rest of the modelwith hinges that do not transfer

momen s.

The external applied forces are only ato n s.

Exercise B - Truss Frame Model


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Objective: Construct andanalyze a frame of truss

elements loaded with 2 nodal

forces.

Geometry: Cross-sectional area= 1 in2.

Material: Aluminum (6061-T6).

Loads: Nodal forces as shownin the image to the right.

Constraints:

.

Ty and Tz constrained atPoint G.

have Tz constrained.


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Beam Elements

Beam Elements

Beam elements are slender


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Beam elements are slenderstructural members that offer

resistance to forces and bending

under applied loads. Beams are found in building

frames, transmission towers and

. A beam differs from a truss in that

a beam resists moments twistin

and bending) at the connections.

Beam Elements


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Beams use a third node todefine the orientation.

-

are defined for bending

weak axes.

Beam Elements


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Guidelines for using beam elements:

The length of the element is much

reater than the width or de th.

The element has constant cross-

sectional ro erties.

The element must be able to transfer

moments.

The element must be able to handle aload distributed alon its len th.

Exercise C - Support Beam Under Gravity


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Objective: Determine themaximum deflection of the

beam due to its own weight.

Geometry: W10 x 100 cross-section.

Material: Steel (AISI 4130).

Loads: Gravity in the -Ydirection.

Constraints:

Each end has constraints

Rz.


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2-D Elements

2-D Elements


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Two-dimensionale emen s are ree- or

four-node elements thatare ormu a e n e -

plane. They are used to

mo e an ana yzeobjects such as bearings,

sea s or s ruc ures suc

as dams.

2-D Elements


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2-D Geometry Types

Axisymmetric: For parts that are

Plane strain: No deflection

(e.g., a large dam).

to the cross-section (e.g., a plate.

2-D Elements

Create wireframe sketches for each part


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Create wireframe sketches for each part

Use the 2-D mesh engine to generate the- .

Exercise D - Axisymmetric Thick-walled Cylinder

Objective: Determine the hoop


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Objective: Determine the hoopstress at the inner radius of the

cylinder from the applied

pressure load.


Loads: Uniform internalpressure of 10,000 psi.

Constraints: The bottom ed ewill have Tz constraints.


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Plate Elements


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Membrane Elements

Three- or four-node elements


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formulated in three-dimensional

space.

Used to model "fabric-like"objects such as tents or cots, or

structures such as the roof of a

sports stadium.

Model solids of a specifiedc ness, w c ex no

stress normal to the thickness.

Composite Elements

There are two types of


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There are two types ofcompos e e emen s:

thin or thick.Each element can have

multiple lamina with

different material propertiesand fiber orientations.

Multiple failure criteria areavailable.

Exercise E - Plate Under Uniform Pressure

Objective: Determine the


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j

maximum stress in the plate

from the applied pressure load.

Geometry: The plate is 10 x 5x 0.25.


Loads: Uniform pressure of 50si.

Constraints:

The two long edges will.

One short edge will have Txand Tz constraints.


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Brick Elements

Brick Elements

Brick elements are


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, ,

eight-node elements

dimensional space.

be used when the

thickness of a part is.

Exercise F - Cantilever Beam Model

Objective: Determine the


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maximum bending stress in the

beam from the applied load.

Material: Steel (4130).

Loads: 10 000 oundsdistributed across the free end.

Constraints:

the fixed end will be fully

constrained.

fixed end will have Tx

constraints.


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Exercise G - Comparing Element Types

Objective: Analyze a beam


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model using different

element types and compare

the results.


2-D: Apply a 100 psi pressure tothe to ed e.

Loads: 100 psi in the -Zdirection on the top of the

beam.

Plate: Model the 10 x 0.5dimensions with a thickness of

0.25. Apply nodal forces

Constraints: Fixed at the leftend and simply supported at

the right.

equ va en o e pressure oa .The forces at the end nodes

should be half the magnitude of

the forces at the interior nodes.

Elements

Beam: Convert the 100 psiload over the 0.25 width to a

Plate: Model the 10 x 0.25

dimensions with a thickness of0.5. Apply a 100 psi pressure

25 lb/in distributed load. load to the top.

Brick: Apply a 100 psi pressure tothe top surface.

Comparison of Results


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Element Deflection Moment Shear (lb) y (psi) xy (psi) y (nearType (inch) (in-lb) center) (psi)

Beam 0.01758 312 156.2 29950 16889

2-D 0.01758 30348 1780 16897

Plate 0.25 0.01757 3034 16896

Plate 0.5

Thick

0.01726 341 32742 16845

Brick 0.01753 31917 2363 16875


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Mesh Convergence

Mesh Convergence

For mesh convergence


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For mesh convergencetesting, it is suggested that

you run at least threeanalyses at different mesh

sizes:

CoarseFineSomewhere in between coarse

and fine

Mesh Convergence

Usually, you will not see the


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Usually, you will not see thedirect equation solutions (such

as displacements) change withthe different mesh sizes.

You will see the numericalmethod answers (such as

stresses conver e to an answer

as the mesh gets finer.

Exercise H - Mesh Convergence

Objective: To perform a 2-Danalysis using plane stress


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analysis using plane stress

e emen s on a c ass ca pro em

by utilizing different meshes of

200, 400, 800, 1600 and 3200.

Geometry: Thickness = 1.0.

Material: Stainless steel (AISI

co -ro e . Loads: 1000 psi on one edge

as shown in the image.

Constraints: Fixed at opposite

end as shown in the image.

Examples of Mesh Convergence


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Mesh Density maxy (psi) Reference (psi) % difference

200 3460.58 3550 2.52

400 3448.13 3550 2.87

800 3502.20 3550 1.35

1600 3538.23 3550 0.33

3200 3556.18 3550 0.17


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Meshing CAD Solid

Models

Meshing CAD Models

Build a solid model in any CAD


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y

solid modeler.

Usin direct CAD/CAE dataexchange or a universal file (IGES,

STEP ACIS o en the model.

Create a mesh on the model.

Mesh Refinement

To optimize solution time, it is


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p

useful to create a fine mesh in

areas where the results arecritical and a coarser mesh in

areas where the results will not

be as high.

You can add refinement ointsto achieve localized refinement.

Exercise I - Bracket Model

Objective: Determine themaximum stress in the bracket


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from a load applied at the hole.

Material: Steel (ASTM - A514).

Loads: 40 ounds in the -Ydirection at the hole.

Constraints: The back surfaceis full constrained.


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Assembly Meshing

When working with multiple parts in


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,

meshes match between the parts if.

If the area where the parts come

oge er s ou no e on e ,then contact should be used to

accoun or e r n erac on.

Exercise J - Hanger Assembly Model

Objective: Determine themaximum stress in the hanger


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assembly from a load applied at

the center of the shaft.

Material: Brackets: Steel (4130)Shaft: Iron

Loads: 100 pounds in the -Ydirection at the center of the

shaft. Constraints: The bottom

surfaces of both brackets are

fully constrained.

Combining Element Types

Any combination of element types is possiblein an assembly.


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Nodes must be matched where the parts meet

in order for loads to be transferred. The available DOF of the element types that

are connected must be considered to avoid

unstable geometry.

Combining Element Types


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Refer to the Combining Beam Elementsw o o e s u or a

available at

www.algor.com/service_support/tutorials

for information on combining element

types.

Contact

Select surfaces in the CAD Solid Model environmentand specify that contact be considered.


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from each other with no restrictions.

The nodes will translate loads when they movetogether.

An iterative solution is used to determine which nodesare in contact.

Contact is not considered during the first iteration.Therefore, it may be necessary to apply weak elastic

.

Exercise K - Linear Contact Model

ec ve: e erm ne e s ress n

the assembly for a maximumclamping load of 1,000 poundsapplied at the end of the lever.

M t i l H dl b d


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Material: Handle, base andlever: Iron

Pins: Steel (ASTM - A36)

Four bolt holes are fullyconstrained.

Top of the handle is fully

applied in the Y direction at

the end of the lever.

cons ra ne . One surface of the lever isconstrained against the Ztranslation.

defined between the handleand the lever, the handle and

the pins and the lever and

Weak elastic boundary

elements in the X and Ydirections should be applied to

the pins.


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Solving Options

Introduction to Solvers

There are many different ways to


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discussed earlier.

u , w

technologies are used that create

.You should usually accept the default

settings, which are optimized for the

fastest processing.

Solver Options

Sparse-


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SkylineVariable bandwidth

Banded

Fixed bandwidth Iterative

Requires a tolerance and initialconditions


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Results

Result Options

The types of results depend onthe type of analysis that is


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the type of analysis that is

performed.For example, a structural analysis

will ive ou dis lacement and

stress results while a thermalanal sis will ive ou tem erature

and heat flux results.


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How to Justify Your Results

The best method for justification is to


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sizes.

emem er, you are approx ma ng anarea or volume with the elements.

The better the quality of the elements,the better the results.

Usually a fine mesh will give moreaccurate answers than a coarse

mesh.


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Presentation

Presentation Guidelines

Use colors that will stand out from.


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Make presentations that everyoneu .

Remember that many people

looking at engineering reports arenot engineers.

Have a standard template.

Include 3-D re resentations withcharts and graphs.

Presentation Options

Contour images

A i ti


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Animations

-

Report generation

Contour Images


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Time-Dependent Plots


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Report Generation


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Other Analysis Types

Thermal Elements

The thermal rod 2-D late

and brick elements are


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and brick elements are

eometricall identical to thestructural elements.

Thermal Nodal Loads

Initial Temperature

Specify a certain


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temperature that an area will

(transient analysis).

Specify a certain

kept at due to a heat source.

Thermal Surface Loads

Convection Assign a convection coefficient


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and the ambient temperature.Radiation

Assign the radiation function and

e am en empera ure.Heat Flux

Assign the amount of heat added

or removed per unit area.

Thermal Element Loads

Heat Generation

Enter the amount of


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volumetric heat generatedin a given part.

Body-to-Body Radiation

Select the surfaces that willexchange heat through


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g g

radiation and assign anemissivity value.

automatically calculate the

elements.

Thermal Contact

Used to simulate imperfect thermal

substance between two parts that is not


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substance between two parts that is not

Define contact pairs in the CAD Solid.

Define the resistance value between thesur aces.

Forced Convection

Perform a fluid flow analysis.

heat transfer analysis


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heat transfer analysis.

e convec on genera e y e

velocity profile will be applied to the

mo e ur ng e ana ys s.

Thermal Results

Temperature

Heat flux


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Exercise L - Thermal Model

Objective: Analyze the thermaleffects of a material containing

hot and cold water pipes.

Material: Steel (ASTM - A514)


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Material: Steel (ASTM A514)

Loads: Small hole: Convection coefficient = 93,380

Ambient temperature = 180F

=

Fsecin

lbsin2

lbsin

,

Ambient temperature= 45F

secn

Electrostatic Elements

The electrostatic 2-D and brick

elements are geometrically


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identical to the structuralelements.

Electrostatic Nodal Loads

Applied Voltages

Specify a certain voltage that


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a node is kept at due to avoltage source.

Temperatures

Specify temperature of a nodefor temperature-dependent

material properties.

Electrostatic Results

Voltage

Current


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Electric field

Electrostatic Analysis

Refer to the Electrostatic and MEMS


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Refer to the Electrostatic and MEMS

u or a ava a e a


for information on performing anelectrostatic analysis.

Fluid Flow Elements

The fluid flow 2-D and brick

elements are geometrically


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identical to the structuralelements.

Fluid Flow Loads

Prescribed Velocityan e use o spec y an n e

velocity or zero velocity along awall


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wall.

an urvesCan be used to model flow

generated by intake, exhaust orn erna ans.

Rotating Reference FramesCan be used to model flow in

rotating machinery.

Fluid Flow Loads

Pressure

Applied normal to the edge of


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2-D elements.Applied normal to the face of

3-D elements.

Gravity

Uses thermal results from a-

analysis.

Fluid Flow Results

Velocity

Pressure


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Reaction forces

Fluid Flow Analysis

Refer to the 3-D Unsteady Fluid Flow


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y

u or a ava a e a


for information on performing a fluid flowanalysis.


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Multiphysics

A multiphysics analysis combines the effectsof multiple analysis types.

The original analysis is performed.


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Another anal sis is set u usin the resultsfrom the original analysis as the loading in the

subsequent analysis.

For some analyses, iterations are required toreach a steady solution.

Steady coupled fluid flow and thermal analysis

solves for fluid and thermal resultss mu aneous y.

Examples of Combining Analysis Types

Apply temperature results from a heattransfer analysis to a stress analysis toana yze erma s ress.

Apply current results from an electrostatic


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analyze Joule heating.

A l velocit results from a fluid flow

analysis to a heat transfer analysis toanalyze forced convection.

pp y empera ure resu s rom a ea

transfer analysis to a fluid flow analysis

Thermal Stress Analysis

Refer to the Static Stress with Linear


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a er a o e s u p ys cs u or a

available at

www.algor.com/service_support/tutorialsfor information on performing a thermal

stress analysis.


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Material Models

Background on Material Models

Material models are subsets of the element.

These properties allow you to make


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properties will be used for each part in the

model.

For example, if a part will see the plasticregion of a stress versus strain curve, you

should select one of the von Mises

material models for an elastic/plasticana ys s.

Isotropic

This is the standard materialmo e . e ma er a proper es

are independent of direction.


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Orthotropic

This material model can haveeren proper es n e ree

orthogonal directions.


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The required properties are identicalto the isotropic material model.

However, you enter separate valuesfor the three directions.

Temperature-Dependent

For some elements, theproper es or o so rop c

and orthotropic materials


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can e e ne on a

temperature basis.

The values are linearlyinterpolated between thetemperature points.

Elastic-Plastic (von Mises)

These material models allow you tospec y a near curve. mo u us

for the elastic region, a yield point


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an a mo u us or e p as c reg on

will be defined.

These material models also allowyou to define a stress-strain curve ifthe material cannot be modeled with

a bilinear curve.

Ogden, Mooney-Rivlin and Hyperfoam

These material models areuse o s mu a e ru er-

(hyperelastic) and foam-like


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ma er a s.

The hyperfoam model will

include compressibilityeffects.

Drucker-Prager

This material model is usedo mo e so s an concre e.


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Viscoelastic and Viscoplastic

These material models areuse o accoun or ra e-

dependent material behavior


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ue o ss pa ve osses ue

to viscous effects.

These material models canbe used to model thermalcreep.


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Piezoelectric

This material model is usedo mo e par s a

experience stress due to a

vo age s r u on


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vo age s r u on.

Curve

This material model allowsyou o npu a u mo u us

versus strain curve to

con ro e e av or o e


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con ro e e av or o e

part.

Exercise M - Nonlinear Material Model

Objective: Analyze a cantileverbeam with an elastic material

model. Determine if yielding

occurs. If yielding occurs,

analyze the model with a plastic

material model


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material model.

Geometry: The beam is 10 longand is 5 x 5 square.

Material: Steel (ASTM - A36)

Loads: 7,000 pounds in the-Y direction at the free end.

Load curveTime

Constraints: The fixed end isfully constrained.

Duration: 10 seconds.

(s)u p er

0 0

10 1

Capture rate: 1 step per second.

Nonlinear Material Models

Refer to the Static Stress with Nonlinear

a er a o e s u or a ava a e a


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a er a o e s u or a ava a e a


for information on performing an analysiswith nonlinear material models.

ec an ca ven mu a on


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ec an ca ven mu a on

Kinematic Elements

Kinematic elements can be either 2- or- .

Kinematic elements do not experience


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.Otherwise, these elements behave just

They have an advantage over flexible

contribution to the size of the global

stiffness matrix. This results in fasterrun times.

Contact Elements

Contact elements can

values in compression


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.These elements can also

which point the stiffness

.

These elements can beused to simulate cables.

Coupling Elements

Coupling elements aid in

"couple" at a known length.

s coup ng s mo e e


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s coup ng s mo e eby introducing a stiffness

w en reac es s eng .This stiffness is calculated

us ng e mo u us o

elasticity, a coupling areaan e eng o e

element.

Dashpot Elements

Dashpot elements canbe used to apply local

damping to a model.

You can specify a


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You can specify adam in coefficient that

will control how muchthese elements affect

motion.

Actuator Elements

Actuator elements

whose lengths can

.


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.They are used to

movement of a

. .,

hydraulic

solenoids).

Slider Elements

A slider element

consists of two collinear

lines connected at one

d


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lines connected at onenode.

will be allowed to move

the other two points,

such as a slot.

Pulley Elements

Pulley elementsconsist of threenodes: driver, pivotand slack.

As the driver node


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As the driver nodemoves toward oraway rom e p vo ,the slack node will

direction by a set.

Pipe Elements

Pi e elements allow ou to

model piping systems under

internal ressure loads.

Th i l t b


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The pipe elements can be

bends.

Hydrodynamic Elements

Hydrodynamic

2- or 3-D elements.

ese e emen s a ow


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for the simulation of

e n erac on o u s

with solids without

cons er ng e e a s

of the flow.

Impact Planes

ecif a wall or floor arallel to the

global X, Y and Z axes.

th h thi l


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through this plane.

Surface-to-Surface Contact

ecif two or more surfaces that

may come into contact during the

event duration.

C i l d t ti d d i


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Can include static and dynamic.

Mechanical Event Simulation


for information on performing a


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p g

Mechanical Event Simulation:

Mechanical Event Simulation withLinear Material Models Tutorial

Mechanical Event Simulation with

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FEA in Practice 400

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