Upload
babak4537
View
213
Download
0
Embed Size (px)
Citation preview
8/3/2019 Http Simcompanion.mscsoftware.com Resources Sites MSC Content Meta WEBINARS and Multimedia 0 WM54 ~Secure Marc Contact Analysis 031110
http://slidepdf.com/reader/full/http-simcompanionmscsoftwarecom-resources-sites-msc-content-meta-webinars 1/30
MSC.Software Confidential
Contact Analysis and Its Parameter Settings
Pei Gu
8/3/2019 Http Simcompanion.mscsoftware.com Resources Sites MSC Content Meta WEBINARS and Multimedia 0 WM54 ~Secure Marc Contact Analysis 031110
http://slidepdf.com/reader/full/http-simcompanionmscsoftwarecom-resources-sites-msc-content-meta-webinars 2/30
MSC.Software Confidential
Contact Analysis and Its Parameter
Settings
Mentat: contact/contact bodies;
Patran: LBCs/contact
8/3/2019 Http Simcompanion.mscsoftware.com Resources Sites MSC Content Meta WEBINARS and Multimedia 0 WM54 ~Secure Marc Contact Analysis 031110
http://slidepdf.com/reader/full/http-simcompanionmscsoftwarecom-resources-sites-msc-content-meta-webinars 3/30
MSC.Software Confidential
A group of elements orgeometric entities maycontact.
Types of contactbodies:Deformable: a group ofelementsRigid: a group ofgeometric entities
Analytical contactdefinition to smoothcontact surface
Rigid contact bodies arespecified bydisplacement or forceapplied to them
Contact Definition
8/3/2019 Http Simcompanion.mscsoftware.com Resources Sites MSC Content Meta WEBINARS and Multimedia 0 WM54 ~Secure Marc Contact Analysis 031110
http://slidepdf.com/reader/full/http-simcompanionmscsoftwarecom-resources-sites-msc-content-meta-webinars 4/30
MSC.Software Confidential
Contact bodies:groups ofelements or
geometric entities
Rigid bodies-geometric entitiesor heat transferelements
This rigid body is
controlled byposition in ydirection, x and zare withoutmotion
8/3/2019 Http Simcompanion.mscsoftware.com Resources Sites MSC Content Meta WEBINARS and Multimedia 0 WM54 ~Secure Marc Contact Analysis 031110
http://slidepdf.com/reader/full/http-simcompanionmscsoftwarecom-resources-sites-msc-content-meta-webinars 5/30
MSC.Software Confidential
Manually orautomaticallydefine thediscontinuousnodes oredges
Analytical Contact:deformable
8/3/2019 Http Simcompanion.mscsoftware.com Resources Sites MSC Content Meta WEBINARS and Multimedia 0 WM54 ~Secure Marc Contact Analysis 031110
http://slidepdf.com/reader/full/http-simcompanionmscsoftwarecom-resources-sites-msc-content-meta-webinars 6/30
MSC.Software Confidential
Rigid Body BC andLoad:
(a) Prescribe
translational androtation velocity andposition;
(b) Prescribe forcethrough extra nodes
8/3/2019 Http Simcompanion.mscsoftware.com Resources Sites MSC Content Meta WEBINARS and Multimedia 0 WM54 ~Secure Marc Contact Analysis 031110
http://slidepdf.com/reader/full/http-simcompanionmscsoftwarecom-resources-sites-msc-content-meta-webinars 7/30
MSC.Software Confidential
Symmetry rigid bodies
Provide easy way toapply symmetryboundary conditions
In rigid bodydefinition in Patran:
LBCs/contact
contact/contactbodies in Mentat
8/3/2019 Http Simcompanion.mscsoftware.com Resources Sites MSC Content Meta WEBINARS and Multimedia 0 WM54 ~Secure Marc Contact Analysis 031110
http://slidepdf.com/reader/full/http-simcompanionmscsoftwarecom-resources-sites-msc-content-meta-webinars 8/30
MSC.Software Confidential
Contact Detection
nuΔA•
MSC S ft C fid ti l
8/3/2019 Http Simcompanion.mscsoftware.com Resources Sites MSC Content Meta WEBINARS and Multimedia 0 WM54 ~Secure Marc Contact Analysis 031110
http://slidepdf.com/reader/full/http-simcompanionmscsoftwarecom-resources-sites-msc-content-meta-webinars 9/30
MSC.Software Confidential
D
D
Default
D (1-B)
D (1+B)
Bias factor
Distance tolerance and Bias factor
Contacted surface
Contactedbody
node not in contactnode in contact
node
penetrated
node not
penetrated
default contact distance tolerancecan be founded in out file
MSC Soft are Confidential
8/3/2019 Http Simcompanion.mscsoftware.com Resources Sites MSC Content Meta WEBINARS and Multimedia 0 WM54 ~Secure Marc Contact Analysis 031110
http://slidepdf.com/reader/full/http-simcompanionmscsoftwarecom-resources-sites-msc-content-meta-webinars 10/30
MSC.Software Confidential
MSC Software Confidential
8/3/2019 Http Simcompanion.mscsoftware.com Resources Sites MSC Content Meta WEBINARS and Multimedia 0 WM54 ~Secure Marc Contact Analysis 031110
http://slidepdf.com/reader/full/http-simcompanionmscsoftwarecom-resources-sites-msc-content-meta-webinars 11/30
MSC.Software Confidential
• Use of the Contact Table is to describe the specific interaction betweencontact pairs (i.e. contact checking is defined by contact interfaces).
• If no contact table is specified, each contact body is assumed to be able totouch the other including self-contact.
• An additional benefit can be in reducing the solution cost by specifyingonly those bodies that can contact.
• Contact tables must be turned on for the loadcase or loadstep duringwhich it is active
34 1
2
Contact Tables
MSC Software Confidential
8/3/2019 Http Simcompanion.mscsoftware.com Resources Sites MSC Content Meta WEBINARS and Multimedia 0 WM54 ~Secure Marc Contact Analysis 031110
http://slidepdf.com/reader/full/http-simcompanionmscsoftwarecom-resources-sites-msc-content-meta-webinars 12/30
MSC.Software Confidential
Contact Tablesanalysis/loadstep creation/solution parameters
contact/contact tables
MSC Software Confidential
8/3/2019 Http Simcompanion.mscsoftware.com Resources Sites MSC Content Meta WEBINARS and Multimedia 0 WM54 ~Secure Marc Contact Analysis 031110
http://slidepdf.com/reader/full/http-simcompanionmscsoftwarecom-resources-sites-msc-content-meta-webinars 13/30
MSC.Software Confidential
wrong bodynumbering
body 1 body 2
1
72
6
5
4
3
●
Check Body 2:u4 = u4(u1, u3)
u5 = u5(u1, u3)
u6 = u6(u3, u2)
u7 = u7(u3, u2)
Skipped, since node 3 has alreadybeen used as a tied node.
Contact Checking
MSC.Software Confidential
8/3/2019 Http Simcompanion.mscsoftware.com Resources Sites MSC Content Meta WEBINARS and Multimedia 0 WM54 ~Secure Marc Contact Analysis 031110
http://slidepdf.com/reader/full/http-simcompanionmscsoftwarecom-resources-sites-msc-content-meta-webinars 14/30
MSC.Software Confidential
Double-sided contact:
jobs/mechanic
al/control
control/advanc
ed contact
control
analysis/job
parameters/contact
parameters
Double-sided and
single-sided are turned
on in:
MSC.Software Confidential
8/3/2019 Http Simcompanion.mscsoftware.com Resources Sites MSC Content Meta WEBINARS and Multimedia 0 WM54 ~Secure Marc Contact Analysis 031110
http://slidepdf.com/reader/full/http-simcompanionmscsoftwarecom-resources-sites-msc-content-meta-webinars 15/30
SC So t a e Co de t a
Using contact table todefine contact checkingorder:
First->second;Second->first;Double-sided;Default;Automatic.
MSC.Software Confidential
8/3/2019 Http Simcompanion.mscsoftware.com Resources Sites MSC Content Meta WEBINARS and Multimedia 0 WM54 ~Secure Marc Contact Analysis 031110
http://slidepdf.com/reader/full/http-simcompanionmscsoftwarecom-resources-sites-msc-content-meta-webinars 16/30
Glue Option In Contact Table:
Complex body can be split up into part which can be meshed easy:
(1)Define each part as a contact body;
(2)Invoke the glue option in contact table to make a physical body.
MSC.Software Confidential
8/3/2019 Http Simcompanion.mscsoftware.com Resources Sites MSC Content Meta WEBINARS and Multimedia 0 WM54 ~Secure Marc Contact Analysis 031110
http://slidepdf.com/reader/full/http-simcompanionmscsoftwarecom-resources-sites-msc-content-meta-webinars 17/30
δ δ
• A positive value is interferenceclosure.
• A negative value is a gap .• Alternatively, include the
interference into the geometry andlet Marc automatically return thesurfaces.
Important: requires the distance toleranceto be larger than the interference.
Interference Fit
gap overlap
MSC.Software Confidential
8/3/2019 Http Simcompanion.mscsoftware.com Resources Sites MSC Content Meta WEBINARS and Multimedia 0 WM54 ~Secure Marc Contact Analysis 031110
http://slidepdf.com/reader/full/http-simcompanionmscsoftwarecom-resources-sites-msc-content-meta-webinars 18/30
Contact Areas and Exclude Segments
Define nodes that are on contact bodies thatpotentially enter contact. Save contact checking.
Exclude edges (faces) that are oncontact bodies that do not entercontact. Save contact checking.
in contact definition inboth Mentat andPatran
MSC.Software Confidential
8/3/2019 Http Simcompanion.mscsoftware.com Resources Sites MSC Content Meta WEBINARS and Multimedia 0 WM54 ~Secure Marc Contact Analysis 031110
http://slidepdf.com/reader/full/http-simcompanionmscsoftwarecom-resources-sites-msc-content-meta-webinars 19/30
Friction Model
friction models :
• Coulomb friction
• “Stick-slip” model
• Bilinear
analysis/job
parameters/contactparameters/frictionparameters
jobs/mechanical/ contact control
MSC.Software Confidential
8/3/2019 Http Simcompanion.mscsoftware.com Resources Sites MSC Content Meta WEBINARS and Multimedia 0 WM54 ~Secure Marc Contact Analysis 031110
http://slidepdf.com/reader/full/http-simcompanionmscsoftwarecom-resources-sites-msc-content-meta-webinars 20/30
A reasonable choice for constant C
(relative sliding threshold) is 1 to 10
percent of the actual sliding velocity.
C very small causes large friction andnumerical convergence. C very large maycause less friction than physically
expected.
F t
vr
1
-1
C = 0.1
C = 1
C = 10
Conventional Coulomb Friction ModelAll friction models in Marc canbe based on either nodal forceor nodal stress
MSC.Software Confidential
8/3/2019 Http Simcompanion.mscsoftware.com Resources Sites MSC Content Meta WEBINARS and Multimedia 0 WM54 ~Secure Marc Contact Analysis 031110
http://slidepdf.com/reader/full/http-simcompanionmscsoftwarecom-resources-sites-msc-content-meta-webinars 21/30
• ∆u t = incremental tangential displacement
• α= friction coefficient multiplier
• β= slip to stick transition region
• ε= small number (εβ » 0)
F t
∆u t
2β
2εβαµ
F n
µ F
n
Stick-Slip Coulomb FrictionModel
nt f f αµ ≤Stick:
Slip: nt f f αµ >
MSC.Software Confidential
8/3/2019 Http Simcompanion.mscsoftware.com Resources Sites MSC Content Meta WEBINARS and Multimedia 0 WM54 ~Secure Marc Contact Analysis 031110
http://slidepdf.com/reader/full/http-simcompanionmscsoftwarecom-resources-sites-msc-content-meta-webinars 22/30
Bilinear Coulomb FrictionModel
Displacement slipthreshold:
δ
Friction force tolerance is for convergence. Donot change, in general.
This model is the
newest, and isrecommended.
MSC.Software Confidential
8/3/2019 Http Simcompanion.mscsoftware.com Resources Sites MSC Content Meta WEBINARS and Multimedia 0 WM54 ~Secure Marc Contact Analysis 031110
http://slidepdf.com/reader/full/http-simcompanionmscsoftwarecom-resources-sites-msc-content-meta-webinars 23/30
Setting the separation force: – Can be done in the contact
table. – OR
jobs/mechanical/contactcontrol/advanced contactcontrol (Mentat);
analysis/jobparameters/contact
parameters/separation(Patran)
Separation Control
The default critical separationforce/stress is given by:10% of the maximum
reaction force.10% of the maximum
contact body normalstress.
MSC.Software Confidential
8/3/2019 Http Simcompanion.mscsoftware.com Resources Sites MSC Content Meta WEBINARS and Multimedia 0 WM54 ~Secure Marc Contact Analysis 031110
http://slidepdf.com/reader/full/http-simcompanionmscsoftwarecom-resources-sites-msc-content-meta-webinars 24/30
• Chattering:
– Suppressed: A node whichcomes into contact may notseparate again in the sameincrement. In general, NotRecommended.
– By default, chattering is
allowed.• Increment:
– Next: A node which shouldseparate can be forced notto separate in the currentincrement but at the
beginning of the nextincrement. In general, NotRecommended.
– By default, it separates inthe current increment.
Additional Separation Parameters forSeparation
analysis/job parameters/contactparameters/separation
MSC.Software Confidential
8/3/2019 Http Simcompanion.mscsoftware.com Resources Sites MSC Content Meta WEBINARS and Multimedia 0 WM54 ~Secure Marc Contact Analysis 031110
http://slidepdf.com/reader/full/http-simcompanionmscsoftwarecom-resources-sites-msc-content-meta-webinars 25/30
Marc Input Deck
Three portions:
(1) Parameters section: before the ‘end’card
-job controls
(1) Model definition section: before the‘end option’ card
-nodes, elements, contactdefinition, BCs and loadsdefinition, tables,materials
(1) History section: after the ‘end option’card
-loadsteps (loading controls)
MSC.Software Confidential
8/3/2019 Http Simcompanion.mscsoftware.com Resources Sites MSC Content Meta WEBINARS and Multimedia 0 WM54 ~Secure Marc Contact Analysis 031110
http://slidepdf.com/reader/full/http-simcompanionmscsoftwarecom-resources-sites-msc-content-meta-webinars 26/30
Contact Definition in Marc Input Deck
Contact Table
MSC.Software Confidential
8/3/2019 Http Simcompanion.mscsoftware.com Resources Sites MSC Content Meta WEBINARS and Multimedia 0 WM54 ~Secure Marc Contact Analysis 031110
http://slidepdf.com/reader/full/http-simcompanionmscsoftwarecom-resources-sites-msc-content-meta-webinars 27/30
Contact works with nearly 100% elementsin Marc, i.e. quad, hex, tet, shell, beam…
Contact works with every material models inMarc, i.e. elastic, isotropic, anisotropic,
orthotropic, plasticity, creep, elastomer,fracture mechanics…
Contact works with coupled thermal-mechanical analysis.
Contact works with remesh (auto-remesh). Post-processing is the same as models
without contact.
Vol A: Theory Manual (Chapter 8 for
Contact)Vol B: Element LibraryVol C: Input Deck, including contactrelated cards in input deck
Where to find contact topics: MarcDocumentations:
Rigid body
Rigid body
MSC.Software Confidential
8/3/2019 Http Simcompanion.mscsoftware.com Resources Sites MSC Content Meta WEBINARS and Multimedia 0 WM54 ~Secure Marc Contact Analysis 031110
http://slidepdf.com/reader/full/http-simcompanionmscsoftwarecom-resources-sites-msc-content-meta-webinars 28/30
Few Tips for Running Marc Contact Jobs
(1) Set contact parameters as default at the initialtry, except in the case that you know thephysical problem. For example, set distancetolerance, bias factor, separation force, etc., asdefault.
(2) If many contact bodies in a model, try to run themodel with fewer contact bodies as the initialtry. This gives insight.
(3) In general, increasing the separation forcestabilize the structure and makes the contact tobe easier to converge.
(4) Glue option stabilizes the structure and makescontact easier to converge. But, whether it canbe used depends on the physical condition
(5) Use contact table to define contact pairs. If youknow the two bodies do not touch, do not definethem contact in the contact table.
(6) Use the card ‘print,5’ in the input deck to debugcontact.
MSC.Software Confidential
8/3/2019 Http Simcompanion.mscsoftware.com Resources Sites MSC Content Meta WEBINARS and Multimedia 0 WM54 ~Secure Marc Contact Analysis 031110
http://slidepdf.com/reader/full/http-simcompanionmscsoftwarecom-resources-sites-msc-content-meta-webinars 29/30
Modeling Contact
Geometrical entities (circular arc andstraight lines)
MSC Marc element 10(full integration axisymmetric)
• Rigid body for channel
– No stress distribution
channel
billet
MSC.Software Confidential
8/3/2019 Http Simcompanion.mscsoftware.com Resources Sites MSC Content Meta WEBINARS and Multimedia 0 WM54 ~Secure Marc Contact Analysis 031110
http://slidepdf.com/reader/full/http-simcompanionmscsoftwarecom-resources-sites-msc-content-meta-webinars 30/30
MSC Marc element 10(full integrationaxisymmetric)
MSC Marc element 40(full integration axisymmetric
thermal)
MSC Marc element 10(full integrationaxisymmetric)
MSC Marc element 10(full integrationaxisymmetric)
Modeling Contact (continued)
Channel is defined as the contactbody of Rigid with Transfer
Channel is defined asdeformable contact body