Hallo,
ich habe ein Problem mit der Kontaktdefinition. Ich möchte ein Rohrsegment vierteln, d.h. sie müssen nachher mit Schrauben (habe ich mit cps modelliert) verbunden werden um wieder das komplette Rohr zu ergeben. Dafür müssen sich die Viertelstücke überlappen. Nun gibt es ja (soweit ich weiß) mindestens 2 Möglichkeiten dies abzubilden. Entweder man arbeitet (da es sich bei mir um SHELL181 Elemente handelt) mit der Keyopt 11 und sorgt in der Geometrie dafür, dass der Spalt bei Einsetzen der Dicke gleich 0 ist.Die andere Möglichkeit ist die, dass man mit den Mittelflächen der Elemente arbeitet und versucht dabei die Durchdingungen, die es natürlich gibt, wenn die Dicke der Elemente angesetzt wird, über unterschiedliche Optionen (CNOF,Keyopt 9,Keyopt 5) zu korrigieren. Nur leider (siehe Bild im Anhang) gibt es bei mir in beiden Fällen immer noch Durchdringungen.
Hier meine Kontaktdefinition mit der Keyopt11 (stellvertretend für eine Überlappungsstelle):
mat,3
MP,MU,3,0.2
ET,3,TARGE170,,
ET,4,CONTA173
!erster Spalt
R,3,,,0.1,
Rmore,1,,,
REAL,3
KEYOPT,4,11,1
KEYOPT,4,9,0
KEYOPT,4,10,2
KEYOPT,4,5,3
! Generieren der Target-Oberflächen
ASEL,S,area,,1
TYPE,3
NSLA,S,1
ESLN,S,0
ESURF,,bottom
! Generieren der Contakt-Oberfläche
ASEL,S,area,,2
TYPE,4
NSLA,S,1
ESLN,S,0
ESURF,,top
ALLSEL
!erster Spalt
R,4,,,0.1,
Rmore,1,,,
REAL,4
KEYOPT,4,11,1
KEYOPT,4,9,0
KEYOPT,4,10,2
KEYOPT,4,5,3
! Generieren der Target-Oberflächen
ASEL,S,area,,2
TYPE,4
NSLA,S,1
ESLN,S,0
ESURF,,top
! Generieren der Contakt-Oberfläche
ASEL,S,area,,1
TYPE,3
NSLA,S,1
ESLN,S,0
ESURF,,bottom
ALLSEL
Nun der Kontakt für die Mittelfläche der Shellelemente:
mat,3
MP,MU,3,0.2
ET,3,TARGE170,,
ET,4,CONTA173
!erster Spalt
R,3,,,0.1,
Rmore,1,0,,spalt
REAL,3
KEYOPT,4,9,0
KEYOPT,4,10,2
KEYOPT,4,5,3
! Generieren der Target-Oberflächen
ASEL,S,area,,1
TYPE,3
NSLA,S,1
ESLN,S,0
ESURF,,bottom
! Generieren der Contakt-Oberfläche
ASEL,S,area,,2
TYPE,4
NSLA,S,1
ESLN,S,0
ESURF,,top
ALLSEL
!erster Spalt
R,4,,,0.1,!0.9
Rmore,1,0,,spalt
REAL,4
KEYOPT,4,9,0
KEYOPT,4,10,2
KEYOPT,4,5,3
! Generieren der Target-Oberflächen
ASEL,S,area,,2
TYPE,4
NSLA,S,1
ESLN,S,0
ESURF,,top
! Generieren der Contakt-Oberfläche
ASEL,S,area,,1
TYPE,3
NSLA,S,1
ESLN,S,0
ESURF,,bottom
ALLSEL
Ich bin für jede Idee und jeden Lösungsansatz dankbar!
Vielen Dank!
Gruß,
Carl
Edit: Hier sind die Datein von CNCHECK:
Keyopt11:
*** NOTE *** CP = 7678.166 TIME= 15:56:42
Deformable-deformable contact pair identified by real constant set 3
and contact element type 4 has been set up.
Contact algorithm: Augmented Lagrange method
Contact detection at: Gauss integration point
Beam/shell thickness effect is included.
Contact stiffness factor FKN 0.10000
The resulting contact stiffness 1312.5
Default penetration tolerance factor FTOLN 0.10000
The resulting penetration tolerance 3.2000
Max. initial friction coefficient MU 0.20000
Default tangent stiffness factor FKT 1.0000
Default elastic slip factor SLTOL 0.10000E-01
The resulting elastic slip 0.14556
Update contact stiffness at each iteration
Default Max. friction stress TAUMAX 0.10000E+21
Average contact surface length 14.556
Average contact pair depth 32.000
Default pinball region factor PINB 2.0000
The resulting pinball region 64.000
*** NOTE *** CP = 7678.166 TIME= 15:56:42
One of the contact searching regions contains at least 240 target
elements. You may reduce the pinball radius.
Auto offset used to close gap/penetration -0.16142
MAX. allow penetration range PMAX 1.0000
Default MIN. allow penetration factor PMIN will be used.
*WARNING*: Initial penetration is included.
*** NOTE *** CP = 7678.166 TIME= 15:56:42
The entire target body has been moved by: x= 0.145129542, y=
-1.787348554E-02, z= -2.062414838E-16 to reduce initial penetration
1.682176753E-02.
The adjusted penetration 0.163047776 was detected between contact
element 24452 and target element 19686.
****************************************
*** NOTE *** CP = 7678.166 TIME= 15:56:42
Deformable-deformable contact pair identified by real constant set 4
and contact element type 4 has been set up.
Contact algorithm: Augmented Lagrange method
Contact detection at: Gauss integration point
Beam/shell thickness effect is included.
Contact stiffness factor FKN 0.10000
The resulting contact stiffness 1312.5
Default penetration tolerance factor FTOLN 0.10000
The resulting penetration tolerance 3.2000
Max. initial friction coefficient MU 0.20000
Default tangent stiffness factor FKT 1.0000
Default elastic slip factor SLTOL 0.10000E-01
The resulting elastic slip 0.14556
Update contact stiffness at each iteration
Default Max. friction stress TAUMAX 0.10000E+21
Average contact surface length 14.556
Average contact pair depth 32.000
Default pinball region factor PINB 2.0000
The resulting pinball region 64.000
*** NOTE *** CP = 7678.166 TIME= 15:56:42
One of the contact searching regions contains at least 240 target
elements. You may reduce the pinball radius.
Auto offset used to close gap/penetration -0.16142
MAX. allow penetration range PMAX 1.0000
Default MIN. allow penetration factor PMIN will be used.
*WARNING*: Initial penetration is included.
*** NOTE *** CP = 7678.166 TIME= 15:56:42
The entire target body has been moved by: x= 0.145129542, y=
-1.787348554E-02, z= -2.062414838E-16 to reduce initial penetration
1.682176753E-02.
The adjusted penetration 0.163047776 was detected between contact
element 29052 and target element 33686.
****************************************
2 CONTACT PAIRS ARE SELECTED
CONTACT PAIR HAVING REAL ID = 3 IS INITIALLY CLOSED
CONTACT PAIR HAVING REAL ID = 4 IS INITIALLY CLOSED
Mittelfläche Shellelemente:
*** NOTE *** CP = 5354.234 TIME= 15:57:49
Deformable-deformable contact pair identified by real constant set 3
and contact element type 4 has been set up.
Contact algorithm: Augmented Lagrange method
Contact detection at: Gauss integration point
Contact stiffness factor FKN 0.10000
The resulting contact stiffness 1312.5
Default penetration tolerance factor FTOLN 0.10000
The resulting penetration tolerance 3.2000
Max. initial friction coefficient MU 0.20000
Default tangent stiffness factor FKT 1.0000
Default elastic slip factor SLTOL 0.10000E-01
The resulting elastic slip 0.14256
Update contact stiffness at each iteration
Default Max. friction stress TAUMAX 0.10000E+21
Average contact surface length 14.256
Average contact pair depth 32.000
Default pinball region factor PINB 2.0000
The resulting pinball region 64.000
*** NOTE *** CP = 5354.234 TIME= 15:57:49
One of the contact searching regions contains at least 240 target
elements. You may reduce the pinball radius.
Auto offset used to close gap/penetration -0.16138
Contact offset towards to contact CNOF 2.0000
MAX. allow penetration range PMAX 1.0000
Default MIN. allow penetration factor PMIN will be used.
*WARNING*: Initial penetration is included.
*** NOTE *** CP = 5354.234 TIME= 15:57:49
The entire target body has been moved by: x= 0.141171438, y=
-1.709757773E-02, z= -1.823938405E-16 to reduce initial penetration
2.080491284E-02.
The adjusted penetration 0.163007944 was detected between contact
element 26009 and target element 21229.
****************************************
*** NOTE *** CP = 5354.234 TIME= 15:57:49
Deformable-deformable contact pair identified by real constant set 4
and contact element type 4 has been set up.
Contact algorithm: Augmented Lagrange method
Contact detection at: Gauss integration point
Contact stiffness factor FKN 0.10000
The resulting contact stiffness 1312.5
Default penetration tolerance factor FTOLN 0.10000
The resulting penetration tolerance 3.2000
Max. initial friction coefficient MU 0.20000
Default tangent stiffness factor FKT 1.0000
Default elastic slip factor SLTOL 0.10000E-01
The resulting elastic slip 0.14256
Update contact stiffness at each iteration
Default Max. friction stress TAUMAX 0.10000E+21
Average contact surface length 14.256
Average contact pair depth 32.000
Default pinball region factor PINB 2.0000
The resulting pinball region 64.000
*** NOTE *** CP = 5354.234 TIME= 15:57:49
One of the contact searching regions contains at least 240 target
elements. You may reduce the pinball radius.
Auto offset used to close gap/penetration -0.16138
Contact offset towards to contact CNOF 2.0000
MAX. allow penetration range PMAX 1.0000
Default MIN. allow penetration factor PMIN will be used.
*WARNING*: Initial penetration is included.
*** NOTE *** CP = 5354.234 TIME= 15:57:49
The entire target body has been moved by: x= 0.141171438, y=
-1.709757773E-02, z= -1.823938405E-16 to reduce initial penetration
2.080491284E-02.
The adjusted penetration 0.163007944 was detected between contact
element 30809 and target element 35629.
****************************************
2 CONTACT PAIRS ARE SELECTED
CONTACT PAIR HAVING REAL ID = 3 IS INITIALLY CLOSED
CONTACT PAIR HAVING REAL ID = 4 IS INITIALLY CLOSED
Da habe ich mich gefragt, woher sich das FTOLN die resultierende Durchdringungstoleranz (resulting penetration tolerance) ausrechnet, weil meine Elemente eigentlich nur jeweils 8mm dick sind und es dann ja 16*0.1=1.6 und nicht 3.2 wären.
[Diese Nachricht wurde von Carl87 am 05. Okt. 2010 editiert.]