solid shell element
TRANSCRIPT
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
ANSYS 9.0Preview II
Grama Bhashyam
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Topics• Mechanics
– Solid Shell Element– Rezoning – 2D– Spotwelds– Pre-Integrated Shell/Beams Sections– Follower Forces– NonLinear Diagnostics and Contact– Temperature Dependent Curve Fitting– Frequency Dependent Harmonic Analysis– Local CYS for Function BC’s– Static Cyclic Symmetry– Component Based Acceleration– CMS Superelements
• Multifield Solver– Flotran Remeshing for Multifield Solver
• Electric and Magnetic Analysis– Electrostatics and Magnetic Forces Calculation– High Frequency Electromagnetic Enhancements– Thermoelectric Analysis
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Solid Shell Element
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Problems associated with a shell theory based FEM
• Nonlinear MPCs or transitional elements are required for connecting shell and solid elements.
• Treatment of variable thickness is unclear.
• Definition of contact interaction needs special attention.
• Difficulties in the specialization of general three-dimensional material laws to plane-stress state.
• Complicated update of rotations in geometrically nonlinear analyses.
ANSYS 9.0:Solid Shell Element
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Numerical locking in low-order 3D solid elements
• The error in the kinematic approximation with linear 3D solid elements becomes apparent in bending dominant problems.
This error is magnified as the thickness decreases, which beyond a certain ratio may make the FE model excessively stiff.
• Current element technologies, such as the enhanced strain (or extra shapes), are not sufficient to remedy this numerical locking in linear 3D solid elements.
ANSYS 9.0:Solid Shell Element
0
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0.6
0.8
1
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1 6 11 16 21 26
Number of Elements Per Edge
Nor
mal
ized
Max
. Def
lect
ion
Solid185 (enhanced strain)
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Element Summary• Involves only displacement
nodal DOFs and features an eight-node brick connectivity. Thus the connection problem between solid and shell elements can be eliminated.
• Performs well in simulating shell structures with a wide range of thickness (from extremely thin to moderate thick).
• Is compatible with 3D constitutive models and automatically accounts for thickness change.
• Performs well for both flat-plate and curved shells.
ANSYS 9.0:Solid Shell Element
1
8
6
4 7
53
R1
R2
R3
X1
X2X3
2
∂∂
∂∂
∂∂
=
∂∂
∂∂
∂∂
=
∂∂
∂∂
∂∂
=
3
3
3
2
3
13
2
3
2
2
2
12
1
3
1
2
1
11
,,
,,
,,
rx
rx
rxR
rx
rx
rxR
rx
rx
rxR
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
FE solution convergence relative to mesh refinement
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0.2
0.4
0.6
0.8
1
1.2
1 6 11 16 21 26
Number of Elements Per Edge
Nor
mal
ized
Max
. Def
lect
ion
Shell181 (enhanced strain)Solid185 (enhanced strain)
SolidShell 190
Normalized shell thickness ( t / L) : 0.001, linear static analysis
ANSYS 9.0:Solid Shell Element
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FE solution convergence relative to mesh refinement
Normalized plate thickness ( t / L) : 0.01, linear static analysis
0
0.02
0.04
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0 5 10 15 20 25 30
Number of Elements Per Edge
Def
lect
ion
at L
ocat
ion
4
Shell181 (enhanced strain)
Solid185 (enhanced strain)
Solid45 (extra shapes)
SolidShel 190
ANSYS 9.0:Solid Shell Element
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FE solution from different modelst/L = 0.01, linear static analysis
Maximum Displacements ------------------------------------------------------------
Ux Uy Uz
SolidShell190 343.41 -642.89 -1395.8
Shell181 Enh 341.91 -639.15 -1395.9
Solid185 Enh 257.12 269.73 -882.97
ANSYS 9.0:Solid Shell Element
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FE solution convergence relative to mesh refinementgeometrically nonlinear static analysis
-0.2
-0.15
-0.1
-0.05
0
0.05
0.1
0.15
0 10 20 30 40 50 60 70 80 90
# elements per edge
Rad
ial D
isp.
At t
wo
corn
ers
Shell181 (pt1)solid190 (pt1)Solid185 (pt1)shell181 (pt2)solid190 (pt2)solid185 (pt2)
ANSYS 9.0:Solid Shell Element
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Modal Analysis of a Hemi-sphere Shell
thickness = 0.001 mesh density = 15 x 15 (Thin Shell)Mode Shell181 Enh Solid185 Enh SolidShell 190
1 3.07759484 8.239738235 3.0717603832 21.24648643 103.9636569 21.228723943 53.86043052 350.1158379 53.829848284 99.48796565 758.7461212 99.481637175 158.4547881 1303.958847 158.47231616 232.5992189 1927.192569 232.66981987 325.8971451 2484.333703 326.0458065
thickness = 0.1 mesh density = 15 x 15 (Thick Shell)Mode Shell181 Enh Solid185 Enh SolidShell 190
1 268.3336331 233.1024418 233.08097732 1401.119808 978.7538942 980.01414573 2400.852477 1761.461958 1763.3263394 3284.527205 2224.35367 2225.6287235 3590.50519 2403.006279 2402.6392126 3670.531134 3157.10644 3155.3068547 4179.724049 3418.795507 3420.088344
ANSYS 9.0:Solid Shell Element
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FE solution from Different Models – Lateral Buckling
L = 100.0 W = 5.0 T = 0.2 (Thin Shell)Mode Shell181 Enh Solid185 Enh Solid190 Enh
1 -5.33E-02 -3.88E-02 -5.32E-022 -1.99E-02 3.88E-02 -1.99E-023 1.99E-02 0.14182488 1.99E-024 5.33E-02 0.34611073 5.32E-02
L = 100.0 W = 5.0 T = 2.0 (Thick Shell)Mode Shell181 Enh Solid185 Enh Solid190 Enh
1 17.892629 18.661164 18.1459592 47.598787 50.793036 48.3937213 82.888858 91.861602 84.700194 128.51412 149.1249 132.4327
ANSYS 9.0:Solid Shell Element
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Car roof assembly part under pressure load (linear static analysis)
Max. Deflection:SOLID186: 0.001521
SOLID190: 0.001575
SOLID185: 0.001290
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Rezoning – 2D
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Why?
• Mesh distortion terminates analysis
ANSYS 9.0:Rezoning
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Solution: rezoning
• What is rezoning?– Remesh base on the deformed domain at a
selected substep– Map the solved variables and achieve equilibrium
based on the mapped variables– Resume the solution based on the new mesh
• Long term goal:– Fully automatic rezoning with different adaptive
criteria to overcome mesh distortion and reduce discretization error
ANSYS 9.0:Rezoning
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Current status
• Manual rezoning for 2D analysis– Elements:
• Plane 182, B-Bar formulation with or without mixed u/P formulation
• All stress states, i.e. plane strain, plane stress, axisymmetric, generalized plane strain
– Materials:• All hyperelastic materials (TB, Hyper…) • Analysis type:
– Static analysis with nlgeom, on
ANSYS 9.0:Rezoning
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Current status (Cont.)
– Loads and boundary conditions:• Displacements• Forces• Pressures• Nodal temperature, applied by BF,TEMP…
– Remesh• Manual remeshing
– Select the elements to remesh– Generate a area– Create the new mesh by ANSYS meshing commands
– Based on multi-frame restart files
ANSYS 9.0:Rezoning
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How Does it work ?
• Based on solved data/batch,list
/prep7
et,1,182...tb,hyper,1,,.....rect,0,b,0,h,esize,el,0,amesh,1d,....
/solunlgeom,ontime,1NSUBST,.....solve
ANSYS 9.0:Rezoning
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How does it work, a pseudo input
• 4 basic steps needed– Step 1
• Retrieve data– Step 2
• Select the region• Generate area• Create new mesh• Transfer load/Bc
– Step 3• Map variables
– Step 4• Resume solving
ANSYS 9.0:Rezoning
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Step 1: Retrieve data
• Command:
ANSYS 9.0:Rezoning
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Step 1: Retrieve data (cont.)
• Functionality:– Check the needed files
• The RDB, RST, RXXX and LDHI files– Rebuild the data environment at the
requested substep by REZONE command– Update the
nodes to the deformed geometry
ANSYS 9.0:Rezoning
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Step 2: Remesh
1. Select the region to remesh– To start by START option
ANSYS 9.0:Rezoning
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Step 2: Remesh
– Select any region on the deformed domain • By any element selection commands • By selecting elements to generate the region to
remesh• The region should have:
– Same material, – Same element type, esys and keyopts– Same thickness (real constant) for plane stress– It can be the whole or part of the domain
ANSYS 9.0:Rezoning
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Step 2: Remesh (Cont.)
2. Generate an area to create new mes
ANSYS 9.0:Rezoning
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Step 2: Remesh (Cont.)
– Functionalities:• Generate an area to create mesh in rezoning• Check the validity of the selected region• Keep compatibility with its neighbors
ANSYS 9.0:Rezoning
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Step 2: Remesh (Cont.)
3. Create new mesh by– Any mesh control
commands (lesize, smrtsize, shpp,..)
– Amesh
• Multiple horizontal Rezoning– Another region can
be chosen and remeshed following the same procedure (in future)
ANSYS 9.0:Rezoning
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New Mesh With BC
Step 2: Remesh (Cont.)
4. Transfer boundary conditions automatically by DONE option
Old Mesh With BC
DONE Will be END in future
ANSYS 9.0:Rezoning
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Step 3: Map solutions
• Intorduce extra substeps to balance the residuals– Rebalance factor: How much residual force has
been balanced, from 0.0 to 1.0– Note: time /external load unchanged
ANSYS 9.0:Rezoning
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Step 3: Map solutions (Cont.)
• Output information ( Mapsol, 10)
ANSYS 9.0:Rezoning
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Step 3: Map solutions (Cont.) ANSYS 9.0:Rezoning
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Step 4: Resume the solution
• Command:– Regular multi-frame restart by
• Antype,,restart…• Solve
ANSYS 9.0:Rezoning
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New files
• Vertical Multiple Rezoning (in future)» Rezone the same/other area during different
time/substeps» All models and solved variables saved in files» Can be restarted from any rezoned model at any
time » Maximum number of rezoning: 99
File name
Regular Run
Rezone 0 Rezone 1 Rezone 2 Rezone 11 Rezone NNRDB RDB RD01 RD02 RD11 RDNNRXXX RXXX RXXX RXXX RXXX RXXXLDHIRST RST RS01 RS02 RS11 RSNN
LDHI
ANSYS 9.0:Rezoning
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Post processing
• Post1 enhancement– SET,List,,Fact
• where Fact is used to control which files are to be listed:• Fact = ALL or blank lists all files (rst,rs01,rs02,etc.)• Fact = LAST lists the last file only (e.g. rs02)• Fact = num of rezoning (e.g. 01) lists only file rsxx
– Example: SET,List,,All
– Other enhancements are coming soon
ANSYS 9.0:Rezoning
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Spotwelds
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New example
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Mesh Independent Spot Weld
• In automotive and/or aerospace industries, many applications require modeling of spot welds between two or more thin parts
• The strength and fatigue properties of thin sheet components are considerably influenced by spot welds
• The traditional model of spot welds:– Matching meshes of different parts at spot weld connection
points.– Effects of spot weld radius is not taken into account– underestimates the strength of the spot weld connection
ANSYS 9.0:Spotweld
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• Parts can be meshed independently• The spot weld can be located anywhere between multiple parts
that are to be connected in a finite element model regardless ofthe mesh.
• A spot weld is defined by the surfaces to be connected and a spot weld node near the surfaces. The spot weld node determines the location of spot weld
• The location of the spot weld can be independent of the locationof the nodes on the surface to be welded.
• The approach takes into account of effects of spot weld radius. ANSYS will generate – RBE3 type MPC via a contact pair on each spot weld surface. The
radius defines the range of force distribution.– A beam element to link the two adjacent surfaces. The beam has
physical radius.• The spot weld can be either rigid or deformed
Mesh Independent Spot Weld ANSYS 9.0:Spotweld
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Create a New Spot Weld Set ANSYS 9.0:Spotweld
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Create a New Spot Weld Set
SWGEN, Ecomp, SWRD, NCM1, NCM2, SND1, SND2, SHRD, DIRX, DIRY, DIRZ, ITTY,I CTY
ECOMP – Spot weld set name. It is the element component and it is used to identify set of spot weld for list, output, and adding more surfaces.
NCM1/NCM2: – Spot weld surfacesPre-defined node components (for select)Meshed areas (for pick)
SND1: – First spot weld node. It determines the location of spot weld. It can be one of node on surface NCM1 or an independent node near the surface. ANSYS will determine the actual location by projecting it onto surface NCM1.
Spot weldsurface 1
Spot weld node 1After projection
Original position of spot weld node 1
Spot weldsurface 1
Spot weld node 1After projection
Original position of spot weld node 1
Projection onto surface Projection direction specified by user
ANSYS 9.0:Spotweld
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Create a New Spot Weld Set
SWRD – Spot weld radius. Each spot weld has a circular projection onto the spot weld surface. By the definition of each contact pair, ANSYS will form RBE3 type constraint equations internally which distribute internal force of contact node (i.e. spot weld node) to the target nodes lying with in the region of spot weld radius.
CONTA175(spot weld node 1)
Spot weldsurface 1
TARGE170 elements
Spot weld radius
CONTA175
Nodes to be constrained
ANSYS 9.0:Spotweld
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Create a New Spot Weld Set
Beam element – connects two spot weld surfaces.Rigid Link is a default : MPC184 with KEYOPT(1)=1Deformed Link : if current defined element type is BEAM188 with proper Material ID and section ID (solid circle)
Spot weldsurface 1
Spot weld node 1
Spot weldsurface 2
Spot weld node 2 A beam elementMPC184/BEAM188
Example:
MP,EX,3,200000000000. ! define spot weld material propertiesMP,NUXY,3,0.3SECTYPE,3,beam,csolid ! define a cylinder beamSECDATA,2.75e-002 ! beam circular radiusET,3,188 ! define a deformed spot weldTYPE,3MAT,3SECNUM,3*SET,NODE1,9000 ! define a spot weld nodeN,NODE1,0.1,0.5,10.2 ! define location of spot weld
SWGEN,SWELD1,2.75e-2,2,3,NODE1 ! Spot sweld name=SWELD1,! RADIUS=2.75e-2,!Spot weld surfaces=AREA 2 and 3.
ANSYS 9.0:Spotweld
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Add more surfaces ANSYS 9.0:Spotweld
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Add more surfaces
SWADD, Ecomp, SHRD, NCM1, NCM2, NCM3, NCM4, NCM5, NCM6, NCM7, NCM8, NCM9Ecomp - The name of an existing spot weld set which composes contact, target and beam elements for the spot weld definition.SHRD - Search radius. It defauts to 4 times of spot weld radius SWRDNCM1-NCM9 - Surfaces to be added the spot weld set. Each surface can input by a pre-defined node component or by a meshed area.
- SWADD command can be repeated to add more surfaces- Max. number of allowabl2 surfaces (including two from basic set) = 11.
Spot weldsurface 1
Spot weld radius
Spot weld node 1
Spot weldsurface 2Spot weld node 2
Spot weldsurface 3Spot weld node 3
Basic spot weld setOriginal position of spot weld node 1
Beam2
Beam1
Spot weldsurface 4Spot weld node 4
More surfaces
Beam3
ANSYS 9.0:Spotweld
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Mesh-Independent Spot Weld
SWDEL, Ecomp- Delete spot weld set- Ecomp - The name of an existing spot
weld set.- If Ecomp = ALL (default) all the spot
welds are deleted
ANSYS 9.0:Spotweld
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Mesh-Independent Spot Weld
SWLIST, Ecomp- List spot weld set- Ecomp - The name of an existing
spot weld set.- If Ecomp = ALL (default) all the spot
welds are Listed
• In POST1 not only elements and contact pairs are listed but also output beam results. For deformed BEAM188 both forces/moments and stresses are listed.
ANSYS 9.0:Spotweld
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Mesh-Independent Spot Weld
Beam188
Conta175
Targ170Output
ANSYS 9.0:Spotweld
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Mesh-Independent Spot Weld
Beam188
Conta175
Targ170Output
ANSYS 9.0:Spotweld
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Pre-integrated shell/beam sections
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Preintegrated Shell Section
• A,B, D and E sub-matrices are symmetric – Allow only bottom symmetric half to be defined – MT, BT are generalized stresses caused by a fully
constrained unit temperature rise• θ is the current temperature, θI is reference
temperature• A,B,D,E,MT,BT can be defined at 6 temperatures
independently• Mass Density of shell/unit area may also be defined
at 6 temperatures
( )
−−
=
BTMT
DBBA
MN I
T θθκε
=
2
1
2221
1211
2
1
γγ
EEEE
SS
ANSYS 9.0:Pre-integrated Shell Sections
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Benefits/Limitations
• Benefits– Missing capability for 4
node shells in ANSYS– Faster: no material point
calculations or storage– Third party software
provide the section stiffness for layered, sandwich or other constructions
– Optimization with homogenized behavior
• Limitations– No output of stresses
• Section resultants (membrane forces and bending moments are available)
– Ability to specify initial stresses is lost
– Linear material behavior– Birth and death is not
supported (currently)– Not meaningful to use at
finite strains • Thickness is not
updated– Offset is not allowed
ANSYS 9.0:Pre-integrated Shell Sections
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Nonlin. Beam General Sections
• We define the “section stiffness” directly as a function of– “section strain” and– Temperature
• There is no material input necessary
• We also define mass density and thermal expansion coefficient– One temp. input per node
(no variation across section)
=
2
1
2
1
2
1
2
1
2
1
2
1
),(),(
0
),(),(
0),(),(
γγθκκε
εε
εε
εε
tSFtSF
tQtF
tFtAx
SSTMMN
CurvatureBen
ding
Mom
ent
ANSYS 9.0:Nonlinear Beam Preintegrated
Sections
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Benefits/Limitations
• Why?– Allows nonlinear
relationships (elastic and elasto-plastic) in terms of generalized stresses and generalized strains
– Very efficient– Allows results from
experiments or another slice analysis as input
• Limitations– No coupling between Axial
and Bending behaviors– Allows nonlinear elastic and
plastic behavior– 20 points of stress-strain
supported– Stress-Strain curve may be
supplied at 6 temperatures– Not applicable for “Warping”
Key-option– Only SMISC quantities are
supported• PRSSOL is meaningless
ANSYS 9.0:Nonlinear Beam Preintegrated
Sections
Beam188/Beam184
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Follower Forces
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Follower load example
P/100P P
Nodal loads
Follower loads
ANSYS 9.0:Follower load
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FOLLW201 element
• A “one” node element – Must be used with nodes
that are attached to shells & beams (uses 6 d.o.f per node)
– No material, section, esys attributes necessary
– Contributes to “stiffness”only for NLGEOM,ON
• NROPT,UNSYM preferred• Follower stiffness
symmetrized for NROPT,FULL
• Real constants– 6 values
• First three n1,n2,n3 entrees are direction cosines of the force vector
• Next three m1,m2,m3 entrees are direction cosines of the moment vector
– The vectors defined by real constants will evolve with deformation (follow the displacements)
ANSYS 9.0:Follower load
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Follower loads
• Follower loads are non-conservative
• Introduce unsymmetric load stiffness contributions
• Introduce stability issues; flutter, dynamic stability
• Often counter intutiveand non-predictable
• A simple cantilever with follower load has flutter instabilities
• SFE command is used to specify load magnitude
• FACE 1 – force• FACE 2 – moment
ANSYS 9.0:Follower load
sfe,nel+1,1,pres,1,-load
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Nonlinear Diagnostics & Contact
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Diagnostic Tool
• Visualization and adjustment tools for initial contact status– CNCHECK, DETAIL: evaluate Contact Pair specifications– CNCHECK, ADJUST: move contact nodes to target to close
gap or reduce penetration– CNCHECK, POST: view contact initial status before solving– CNCHECK, RESET: reset contact default settings
ANSYS 9.0:Contact
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Diagnostic Tool
• NLDIAG,CONTACT,on– File Jobname.cnd is written during
iteration/substep/loadsetp– Lists on a pair-based items.– Identify when and how contact occurs.– When divergence occurs, it
determines the regions where contact is unstable.
ANSYS 9.0:Contact
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Penalty based shell-shell Assembly
• Prevent overconstraint when contact occurs on both sides of shell
Surface-surface contact:
Only translation DOF’s are constrained
Penalty based shell-shell:
Both translation & rotation DOF’s are constrained
Rotationalresistance
ANSYS 9.0:Contact
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Temperature Dependent Curve Fitting
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Purpose
• The purpose of the project is to generate coefficients from temperature dependent experimental data.
• This is applicable to all HyperElastic, ViscoElastic(Prony Series) and Implicit Creep models.
• This is an extension of the existing curve fitting capabilities for all the above mentioned material models.
ANSYS 9.0:Temp. Dependent Curve
Fitting
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Experimental Data Definition
• Add data at various temperatures and as many as you like in the following format. This is applicable to all experimental data types.(uniaxial, biaxial, shear, volumetric, creep,…)Example;/temp,1000.0 10.1 20.2 3
• Only one temperature per file.
ANSYS 9.0:Temp. Dependent Curve
Fitting
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New Functionality
• A new option is added to enable temperature dependent curve fitting.• With the temperature dependent option on, The solver filters
experimental data depending on the temperature and generates separate sets of coefficients at corresponding temperatures.
• There are two solution procedures– Set a temperature and solve. Repeat this for all other temperatures,
verify/view the results and save the coefficient to ansys material database.– Set the temperature to “all” and solve. This will solve for all temperatures at
once. Verify/view the results and save to database.• The plot page plots the curves at all temperatures.
ANSYS 9.0:Temp. Dependent Curve
Fitting
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Step by step procedure
• Import Experimental Data – One temperature per file
• Pick an appropriate material model.• Enable temperature dependent curve fitting (tbft,set,categ,func,opt,tdep,1)• Solution
– Set the temperature (tbft,set,categ,func,opt,tref,temp1)– Solve– Set the temperature (tbft,set,categ,func,opt,tref,temp2)– Solve ……
Or– Set the temperature (tbft,set,categ,func,opt,tref,all)– Solve command solves for coefficients at all temperatures.
• Verify the results using plots for all temperatures.• Save the data to Ansys database.
ANSYS 9.0:Temp. Dependent Curve
Fitting
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Sample Script
/prep7! Define Materialtbft,fadd,1,hyper,moon,2
! Define Uniaxial Datatbft,eadd,1,unia,unia-100.exptbft,eadd,1,unia,unia-200.exptbft,eadd,1,unia,unia-300.exptbft,eadd,1,unia,unia-400.exp
! Define Volumetric Datatbft,eadd,1,volu,volu-100.exptbft,eadd,1,volu,volu-200.exptbft,eadd,1,volu,volu-300.exptbft,eadd,1,volu,volu-400.expContd ………..
ANSYS 9.0:Temp. Dependent Curve
Fitting
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Sample Scripts contd.
tbft,set,1,hyper,moon,2,tdep,1
tbft,set,1,hyper,moon,2,tref,100tbft,solve,1,hyper,moon,2,0
tbft,set,1,hyper,moon,2,tref,200tbft,solve,1,hyper,moon,2,0
tbft,set,1,hyper,moon,2,tref,300tbft,solve,1,hyper,moon,2,0
tbft,set,1,hyper,moon,2,tref,400tbft,solve,1,hyper,moon,2,0a
tbft,list,1
tbft,fset,1,hyper,moon,2tblis,all,allfini
ANSYS 9.0:Temp. Dependent Curve
Fitting
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Temperature dependent Uniaxial Experimental DataANSYS 9.0:
Temp. Dependent Curve Fitting
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Solver PageANSYS 9.0:
Temp. Dependent Curve Fitting
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
HyperElastic Polynomial –Uniaxial Data Fit at four temperatures
ANSYS 9.0:Temp. Dependent Curve
Fitting
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Saved Coefficients inAnsys Material GUI
ANSYS 9.0:Temp. Dependent Curve
Fitting
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Frequency Dependent Harmonic Analysis
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Frequency Dependent Harmonic Analysis
• Objectives– Frequency and temperature dependent
elastic properties– Frequency and temperature dependent
damping coefficient– Calculate damping matrix from elements – Support full harmonic response analysis
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Frequency Dependent Harmonic Analysis
• Equation of motion
[ ]{ } [ ]{ } [ ]{ } { }FuKuCuM =++ &&&
[M] – mass matrix
[K] – stiffness matrix[C] – damping matrix
[ ] [ ]∑ ωµω= ))(),(E(KK e
[ ] [ ]∑= eCC [ ] [ ]ee K)(sC ω=
s – structure damping coefficient
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Frequency Dependent Harmonic Analysis
– Elasticity• TB,ELASTIC Command
Isotropic elasticity (Ex, NUxy)Orthotropic elasticity (Ex,Ey,Ez,Gxy,Gxz,Gyz,Nuxy,Nuxz,Nuyz)Use TBFIELD to define frequency and temperaturedependent elastic properties
– Damping coefficient• TB,SDAMP (SDAMP - stand for structure damping)
Use TBFIELD to define Frequency and temperaturedependent damping coefficient
– Element supports• 182, 183, 185, 186, 187 for all stress states
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Frequency Dependent Harmonic Analysis
• Elasticity– The Command
TB,ELASTIC,MAT,NTEMP,NPTS,TBOPTMAT
Material numberNTEMP
Number of temperatureNPTS
Number of data point2 – for isotropic elasticity9 – for orthotropic elasticity
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Frequency Dependent Harmonic Analysis
• Elasticity– The Command
TB,ELASTIC,MAT,NTEMP,NPTS,TBOPTTBOPT elastic data table optionIEL isotropic elasticity behavior, the
defaultOELN orthotropic elasticity behavior
with minor Poisson ratio
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Frequency Dependent Harmonic Analysis
• Procedure• Use ANSYS full harmonic analysis procedure
ANTYP,HARM• Parallel to other ANSYS full harmonic analysis
with damping effect through commands such as ALPHA and BETA; MP,DAMP; DMPR; …
• The DAMPING matrix from TB,SDAMP is additive to other damping matrix, and therefore the damping effect is “add on”
• TB,ELASTIC can be used with TB,SDAMP and also MP,DAMP;ALPHA and BETA; DMPR.
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Frequency Dependent Harmonic Analysis
• Example• Define an elastic data table with frequency dependence
TB,ELASTIC,1, ,2 ! Elastic data tableTBFIELD , FREQ,25 ! First frequency valueTBFIELD , TEMP,25 ! First temperature valueTBDATA,1,2.50e11,0.3 ! E and µTBFIELD ,FREQ,50 ! Second frequency valueTBDATA,1,2.0e11,0.3TBFIELD ,TEMP,50 ! Second temperature valueTBFIELD ,FREQ,75 ! Third frequency valueTBDATA,1,1.5e11,0.3TBFIELD ,FREQ,100 ! Forth frequency valueTBDATA,1,1.0e11,0.3
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Frequency Dependent Harmonic Analysis
• Example• Define a damping coefficient data table with frequency
dependence TB,SDAMP,1, ,1 ! damping data tableTBFIELD , FREQ,25 ! First frequency valueTBFIELD , TEMP,25 ! First temperature valueTBDATA,1, 0.2 ! Damping co.TBFIELD ,FREQ,50 ! Second frequency valueTBDATA,1, 0.19TBFIELD ,TEMP,50 ! Second temperature valueTBFIELD ,FREQ,75 ! Third frequency valueTBDATA,1, 0.18TBFIELD ,FREQ,100 ! Forth frequency valueTBDATA,1, 0.17
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Frequency Dependent Harmonic Analysis
• Example– SOLUTION procedure
/SOLUTIONANTYPE,HARMIC ! Harmonic response analysisHROPT,FULL ! Full harmonic responseHROUT,OFF ! Turn off printoutHARFRQ,25,400 ! Frequency rangeNSUB,16,,16
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Frequency Dependent Harmonic Analysis
• Example: Cantilever beam subject to uniform pressure
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Frequency Dependent Harmonic Analysis
• Material data
0.0E+00
5.0E+10
1.0E+11
1.5E+11
2.0E+11
2.5E+11
3.0E+11
0 100 200 300 400
Young's modulus as function of frequency
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Frequency Dependent Harmonic Analysis
• Material data
Damping coefficient as function of frequency
0
0.05
0.1
0.15
0.2
0.25
0 100 200 300 400
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
0.0E+00
2.0E-07
4.0E-07
6.0E-07
8.0E-07
1.0E-06
1.2E-06
0 100 200 300 400 500
Results from FDM
Expected results
Frequency Dependent Harmonic Analysis
• Comparison of displacement
di
Note:Reference solution is obtained by defining material properties with the corresponding frequency at every load step
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Frequency Dependent Harmonic Analysis
• On going development– Frequency dependent anisotropic elasticity– Extension to support SHELL181,
BEAM188, BEAM189, LINK180, SHELL208, SHELL209
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
0.0E+00
2.0E-07
4.0E-07
6.0E-07
8.0E-07
1.0E-06
1.2E-06
0 100 200 300 400 500
Results from FDM
Expected results
Frequency Dependent Harmonic Analysis
• Comparison of displacement
di
NoteReference solution is obtained by using material property defined by MP and change the property with the frequency every load step
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
New Material DefinitionStress vs. Plastic strain Curve
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Requirements
• Directly define stress vs plastic strain data for multilinear isotropic hardening plasticity (MSIO)
• Directly define stress vs plastic strain data for multilinear kinematic hardening plasticity (KINH)
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Stress Plastic Strain Data
• The commandTB,PLASTIC,mat,ntemp,npts,TBOPTmat = material numberntemp = number of temperaturenpts = number of stress plastic strain pointsTBOPT = MISO for isotropic hardening
= KINH for kinematic hardeningNote:The first data point is always the yield stress with zero plastic strain.
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Stress Plastic Strain Data
• Example multilinear isotropic hardening plasticity
TB,PLASTIC,1, ,10,MISOTBPT,, 0.000000, 0.3000D+05TBPT,, 0.000378, 0.3875D+05TBPT,, 0.000955, 0.4500D+05TBPT,, 0.001617, 0.5000D+05TBPT,, 0.002406, 0.5312D+05TBPT,, 0.003236, 0.5563D+05TBPT,, 0.004067, 0.5813D+05TBPT,, 0.004940, 0.6000D+05TBPT,, 0.006771, 0.6250D+05TBPT,, 0.010561, 0.6560D+05
Stress vs. plastic strain curve
0
10000
20000
30000
40000
50000
60000
70000
0.000 0.002 0.004 0.006 0.008 0.010 0.012
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Stress Plastic Strain Data
• Example for a multilinear kinematichardening plasticity
TB,PLASTIC,1, ,10,KINHTBPT,, 0.000000, 0.3000D+05TBPT,, 0.000378, 0.3875D+05TBPT,, 0.000955, 0.4500D+05TBPT,, 0.001617, 0.5000D+05TBPT,, 0.002406, 0.5312D+05TBPT,, 0.003236, 0.5563D+05TBPT,, 0.004067, 0.5813D+05TBPT,, 0.004940, 0.6000D+05TBPT,, 0.006771, 0.6250D+05TBPT,, 0.010561, 0.6560D+05
Stress vs. plastic strain curve
0
10000
20000
30000
40000
50000
60000
70000
0.000 0.002 0.004 0.006 0.008 0.010 0.012
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Stress Plastic Strain Data
• TB,PLASTIC applies whenever TB,MISO or TB,KINH apply
– TB,PLASTIC,,,,MISO is equivalent to TB,MISO– TB,PLASTIC,,,,KINH is equivalent to TB,KINH– TB,PLASTIC can be combined with other material
models, such as CHABOCHE, CREEP, RATE, HILL
– Use TBTEMP to define a temperature dependent data table
– Support elements 180, 181, 182, 183, 185, 186, 187, 188,189, 208, and 209
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Preprocessing
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
• Function loads can now interpret (x,y,z) in local coordinate system
ANSYS 9.0:Sim. Support
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
• Post1 surface calculations- New “Cylinder” surface. Creates a cylindrical cut through the model of user specified radius and orientation.
• Map results on to the cylindrical surface to perform calculations
ANSYS 9.0:Sim. Support
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Static Cyclic Symmetry
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Static Cyclic Symmetry
• Plotting of /CYCEXPAN’ded B.C’s in POST• B.C. application through ‘Picking’• Point loads and Surface loads
• B.C. through nodes, keypoints picking to apply forces and displacements
• B.C. through picking - pressure on elements, lines, areas and displacement on lines and areas
• Verify results and compare with commands
• Imaginary loads (F, SF, D)• Post data structure – real and imaginary
results
ANSYS 9.0:Linear Dynamics
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
B.C. plotting in POST
B.C. through picking - areas
AREA LKEY LOAD LABEL VALUE(S)
3 1 PRES -200.00 0.0000 SECTOR 1
3 1 PRES -200.00 0.0000 SECTOR 3
9 1 PRES 10.000 0.0000 SECTOR 2
9 1 PRES 10.000 0.0000 SECTOR 5
10 1 PRES 10.000 0.0000 SECTOR 2
10 1 PRES 10.000 0.0000 SECTOR 5
12 1 PRES 20.000 0.0000 SECTOR 7
ANSYS 9.0:Linear Dynamics
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Component based Acceleration
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Component Based Acceleration
• Apply apply inertia forces on different element components, based on the accelerations on the different parts of the structure.CMACEL, CM_NAME, CMACELX, CMACELY, CMACELZCM_NAME The name of the element component
CMACELX, CMACELY, CMACELZ
Linear acceleration of the element component CM_NAME in the global Cartesian X, Y, and Z axis directions, respectively.
ANSYS 9.0:Linear Dynamics
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Example/prep7…nsel,s,loc,z,0,-72esln,,1cm,roof1,elemnsel,s,loc,z,-75,-140eslncm,roof2,elem nsel,s,loc,z,-150,-220esln,,1cm,roof3,elemnsel,s,loc,z,-225,-300eslncm,roof4,elemesel,allnsel,alFini
/soluantype,staticcmacel,roof1,,0.36cmacel,roof2,,0.37cmacel,roof3,,0.38cmacel,roof4,,0.39solvefini
ANSYS 9.0:Linear Dynamics
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
CMS - Superelements
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Expansion in transformed location
• Expand the substructure results in transformed location if SETRAN or SESYMM command is applied in USE pass.
1. SEEXP, Sename, Usefil, Imagky, ExpoptExpopt
Key to specify whether the superelement expansion pass 2. RSTOFF, Lab, OFFSET
Offsets node or element IDs in the FE geometry record.
ANSYS 9.0:Linear Dynamics
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Example
!left wing is from right wing in USE pass/prep7et,1,50se,RightWingsesymm, LeftWing, X, 100, se2, subse,se2cp,...fini
! expansion Pass /assign,rst,rightwing,rst/solutionexpass,onseexp,rightwing,use, ,onrstoff, node, nof2rstoff, elem, eof2numexp,allsolvefinish
ANSYS 9.0:Linear Dynamics
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
CMSFILE command enhancement
• Handle the CMS result file, but also other types of result file. So, the user can keep FEM parts in CMS analysis and postprocessthe substructure expanded result files and FEM result files together.
CMSFILE, Option, Fname, Ext, CmsKeyCmsKey
Valid only when adding a results file (Option = ADD or ALL), this key specifies whether or not to check the specified .rst file to determine if it was created via a CMS expansion pass:ON — Check (default).OFF — Do not check.
ANSYS 9.0:Linear Dynamics
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Re-meshing for Ansys Flotran inMultiField solver
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Motivation
• For FSI problem when fluid mesh is highly distorted (affect the accuracy) or mesh fails in morphing
• Improve the accuracy when the mesh was distorted by ALE mesh moving scheme.
• Enable user to solve FSI problem with large domain changes when the mesh fails in ALE mesh update process by using Ansys MF solver.
ANSYS 9.0:Remesh in MF Solver
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
How to use
• Use FLDATA39 to setup the re-meshing parameters for fluid field in Multifieldsolver, no new MF commands required by re-meshing.
• FLDATA39, REMESH, Label, Value
ANSYS 9.0:Remesh in MF Solver
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Example:Rigid body rotation of a valve in a tube
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Electrostatic & Magnetic forces
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Basis & advantagesThe theoretical basis for the projects is based on a new 3D electromagnetic formulation that uses analytic formulae for integral and post evaluations.
• General– + Reluctance forces due to material changes (not available currently)– + Current segment forces like electrodes (not available currently)– + Lorentz forces in permeable material (not available currently)– + Consistently combine these forces (there is confusion here now)– ! Yes, presently we can't do these forces; I think competition can't either
• Fast: • Accurate• Consistent
– Electric and magnetic methodology are the same– Easier usage, no prep7 action needed
• no need to create think air layer around body (present usage)• no more flagging (present usage)
– Users, at post1, select nodes on bodies of interes and call a FMGN to report forces– Compliant with present FMAGSUM: existing input continue to run
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
2-D ELECTROSTATIC FORCES
gVN
xWF r
t
20
argεε
=∂∂
=Simplified expression for combdrive driving force (ignores fringing effects [1,2]):
Electrostatic Force (N)
Driving (x) Transverse (y)
Simplified analytical [1,2] 5.31⋅10-9 0.0
ANSYS (Maxwell Stress Tensor)
3.55⋅10-9 0.006⋅10-9
ANSYS (New Virtual Work)
5.65⋅10-9 0.005⋅10-9
Potential distribution between comb fingers
Electrostatic forces developing between comb fingers
REFERENCES
1. T.-C. H. Nguyen W.C. Tang and R.T. Howe. Laterally driven polysilicon resonant microstructures. Sensors and Actuators A, 20:25–32, 1989.
2. M.W. Judy W.C. Tang, T.-C.H. Nguyen and R.T. Howe. Electrostatic-comb drive of lateral polysilicon resonators. Sensors and Actuators A, 21-23:328–331, 1990.
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
3-D ELECTROSTATIC FORCES
Potential distribution between two spherical electrodes
Electrostatic forces developing between two electrodes
REFERENCES
http://hyperphysics.phy-astr.gsu.edu/hbase/electric/capsph.html#c1
.
22
20
112
−
=∂∂
=
baa
VaWF r
aεπε
22
20
112
−
−=∂∂
=
bab
VbWF r
bεπε
Forces developing between two spherical electrodes:
Radial Electrostatic Force (N)
Fa (inner) Fb (outer)
Analytical model 2.23⋅10-6 -0.56⋅10-6
ANSYS (Maxwell Stress Tensor)
1.59⋅10-6 -0.79⋅10-6
ANSYS (New Virtual Work)
2.21⋅10-6 -0.55⋅10-6
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
3-D MAGNETIC FORCES: TEAM20 BENCHMARK
REFERENCES
1. M. Gyimesi, D. F. Ostergaard, “Analysis of Benchmark Problem TEAM20 with Various Formulations”, Proceedings of TEAM Workshop, COMPUMAG, Rio, 1997.
2. M. Gyimesi, D. F. Ostergaard, “Mixed Shape Non-Conforming Edge Elements”, IEEE Transactions on Magnetics, Vol. 35 No. 3, 1999, pp. 1407-1409.
3. M. Gyimesi, D. F. Ostergaard, “Non-Conforming Hexahedral Edge Elements for Magnetic Analysis”, IEEE Transactions on Magnetics, Vol 34 No. 5, 1998, pp. 2481-2484.
Vertical (z-direction) force (N)1000 A-turns 3000 A-turns 5000 A-turns
Experimental (target) 8.10 54.4 80.1
ANSYS (Old Virtual Work) 7.24 51.3 76.7
ANSYS (New Virtual Work) 7.25 51.4 76.8
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
High Frequency Electromagnetics
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
High-Frequency Electromagnetics
• Electromagnetic Wave Scattering from Periodic Structures and Frequency Selective Surface (FSS)
– Very difficult to simulate whole structure by FEA with HUGE number of DOFs
– Simplify the simulation using unit cell with Periodic Boundary Condition
Plane Wave
Periodic Structure
Master surfaceSlave surface
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
High-Frequency Electromagnetics
– Vector basis function with Floquet principle leads toEslave = Emastere-jΨ
– Hex, Tet, Wedge and Pyramid element– Coupling between master and slave surface– Plane wave excitation – Perfectly Matched Layers (PML) absorbing boundary
condition– Reflection/Transmission and radar cross section (RCS)
Calculation• Lumped Circuit Model in FEA Full-Wave Electromagnetic Solver
Microstrip line
FEA Mesh
Lumped circuit modelRLC
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
High-Frequency Electromagnetics
– Present the lumped circuit parameter in the high frequency electromagnetic distribution parameter system
– Integrate lumped RLC circuit model into full-wave electromagnetic FEA solver
– Hex, Tet, Wedge and Pyramid element
• Improve Fast Frequency Sweep Performance– Variation Technology (VT) for broadband Fast
Frequency Sweep– Speed up VT performance ~20% with the similar
memory requirement– PML termination with acceptable absorbing rate– Hex, Tet, Wedge and Pyramid element
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
High-Frequency Electromagnetics
• Special Absorption Rate (SAR) Calculation– Calculation of SAR in FEA element for lossy material– Plot/Print SAR distribution using ETABLE of ANSYS
postprocessor– Available in Hex, Tet, Wedge and Pyramid element
• Power Calculation of a N-port High-Frequency Electromagnetic System
– Input/Output power at ports– Dissipated power in N-port system– Power reflection/transmission coefficient, return loss
and insertion loss at ports
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Thermoelectric Analysis
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
• Enhance the thermoelectric analysis to include (in addition to Joule heating) – Seebeck, Peltier, Thomson effects– transient electrical effects
Objectives
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
• New thermoelectric analysis option on the coupled-field elements– PLANE223, SOLID226, SOLID227– keyopt(1)=110
Electric field on Thermal field on Structural field off
• New material property to input Seebeck coefficients – MP,SBKX (also SBKY, SBKZ) - to model Seebeck and Peltier effects– MPDATA,SBKX (also SBKY, SBKZ) – to model Thomson effect
• Transient thermoelectric analysis now uses electric permittivity– MP,PERX (also PERY, PERZ) – to capture transient electrical effects
Scope
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Elements - Summary
SF: CONV, HFLUX, RADBF: HGEN
Loads
3-D 10-node3-D 20-node2-D 8-nodeNameCoupled-field solid
SOLID227SOLID226PLANE223
0 - Plane1-Axisymmetric
KEYOPT(3)
KZZ, RSVZ, SBKZ, PERZ
KXX, KYY, RSVX, RSVY, SBKX, SBKY, DENS, C, ENTH, PERX, PERYMaterial
Properties
Temperature (TEMP) – Heat flow (HEAT)Electric scalar potential (VOLT) - Electric current (AMPS)
DOFs-Reactions
110 (thermoelectric analysis)KEYOPT(1)MP,PP,EDProduct
Geometry
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
• To do a thermoelectric analysis you need to– use one of these element types - PLANE223, SOLID226, SOLID227– set KEYOPT(1)=110– specify electrical resistivity (RSVX), thermal conductivity (KXX), and other
applicable properties (DENS,C,ENTH) if needed
• To include Seebeck/Peltier thermoelectric effects– specify Seebeck coefficients (SBKX)– specify the temperature offset from absolute zero to zero (TOFFST)– temporarily, you have to set KEYOPT(2)=1 to activate Seebeck/Peltier
coupling (in the final release, the coupling will be activated automatically upon the definition of Seebeck coefficients)
• To add electric transient effects – specify electrical permittivity (PERX)
Procedure
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Example - Peltier Cooler
p-type material
n-type material
Iout
Iin= 10 A
conductor
Cold side T= -3 oC
Hot side T= -54 oC
Temperature distribution
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
• TECs are used in applications where temperature stabilization, temperature cycling, compact or pinpoint cooling are required:– Electronic and optical component cooling
• CPU, photodetectors, low noise amplifiers, laser diodes
– Consumer products• Portable food/beverage coolers, automotive seat cooling/heating
– Medical, laboratory and scientific equipment• Blood analyzers, thermal cycling devices (blood, lymph, DNA), heart and
eye surgery
– Military & Space• Naval navigation, night vision equipment, guidance systems
– Indoor environmental devices• Conditioners, fans, humidifiers
Markets and Applications
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
HEAT TRANSFER ENHACEMENTS –
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Radiosity Solution Enhancements
Three major enhancements at ANSYS9.0(NOT available for FLOTRAN)-Posprocess radiation data via SURF251& SURF252 element types-Efficient solution for fine surface meshes
via decimation/agglomeration-Efficient solution for models with
symmetry planes
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Decimation Concept
Radiation via coarse SURF251
Thermal via PLANE55
/SHRINK,.5 used for clarification
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Radiation Enhancements
The following new commands allow generation of SURF251/252 elements:
RDEC : This specifies decimation parameters for coarsening
RSYM: allows user to define symmetry parameters
RSURF: action command to generate the surface elements
(Details in attachment command.doc)
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Radiation Enhancements
Use the NMISC records of SURF251/252Elements to print /display the following:-area of each surface element-temperature of surface element-emissivity of surface element-enclosure # of surface element-net radiation heat flux leaving surface element(see attached input files for details)
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Planer vs Cyclic Symmetry
POS(plane of symmetry) specified by user via CS command
COR(center of rotation) specified by user via CS command
1 reflection only
2 repetitions
original
original
Reflection is NOT the same as Repetition !!!
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Planer Symmetry
SURF251
PLANE55
2 Planes of symmetry
Input file is RSYMtest1.dat
ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.
Cyclic Symmetry
Center of rotation
Cyclic symm plane
SURF251
PLANE55
Input file is RSYMtest2.dat