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difficulties CONTACT problem with plasticity using ABAQUS FEA code.

Hello everyone:

1.  I have built a FEM model 2D plane strain using ABAQUS/Standard (CPE4R) elements,

2. I am  modeling the contact between a cylinder and a plate in 2D.

3. The Cylinder material is given is ELASTIC ISOTROPIC material with no plasticit E=310 GPa

4.  The plate is with a Ramberg-Osgood plasticity with a Young's modulus E=210 GPa.

5. The mesh at the the contact point is VERY refined element characteristic length is about 1 micron. (My model units are  (mm,N,sec)).

6. I validate my model with hertz contact theory and it works well.

7. I try to validate with mindlin theory (Pressure and shear), when I plot the pressure profile at the contact zone I get a well behaved curve. However, the Shear at the contact zone is NOT well behaved, it shows alot of fluctuations and noisy response.

 8. I tried to modify the mesh size at the contact zone (increased in fact) but the response is still the same.

 

P.S. if I remove PLASTICITY from the model, it works fine both in NORMAL pressure and IN SHEAR. 

Question:

 1. How can this be corrected ?

2. Is there a particular plastic model that I should used (my material is a metal) ?

3. can CONTACT CONTROLS be used to remedy this? if yes, how ? 

Comments

Amir Siddiq's picture

Hi,

Before jumping into the details, few questions:

- How do you apply loading?

- What contact properties have you used? For normal as well as tangential?

- I would recommend to use other plasticity model with isotropic hardening etc. (just to check)

- Most importantly how different are your values of normal stress than shear stresses? May be shear part depending upon the type of loading might be negligible?

- Also, ensure that you are using finite sliding algorithm in ABAQUS if you are expecting finite slip.

These are the few points which I can think of at this time. If you can explain a bit then, I might be able to give some more.

All th ebest.

Amir

aslam alikum. i need ur help my brother.i'm facing problems with contact problems code .the idea was contact problems in 2D using ALE

 (Arbitrary Lagrangian-Eulerian algorithm). so if you can help me, you can send me a message.my e-mail is mimo-shishi@hotmail .comm

Hi Amir:

Thanks for taking the time to reply. To answer all your questions I have included here the input file I am working with maybe that could shed some light on the difficulties I have.

 

 **+--------------------------------+                                                                             #
**  UNITS                          |                                                                             #
**+--------------------------------+                                                                             #
** Length: mm  (1E-3 m)                                                                                          #
** Force:  Newton (1 N)                                                                                          #
** Stress: MPa                                                                                                   #
** angle: degrees                                                                                                #
**                                                                                                               #
**---------------------------------------------------------------------------------------------------------------#
**
*PREPRINT,MODEL=YES,HISTORY=NO,CONTACT=NO
*HEADING
   CYLINDER/PLANE CONTACT NOWELL & HILL MODEL
**
**--------------------------------------+
**  DEFINE SEED NODES OF THE SPHERE     |~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~#
**--------------------------------------+
**
*NODE,NSET=NCenterS
1, 0., 0.
*NODE,NSET=LINE1S
2, 12.0, -28.6478897565
162, 12.0, -14.3239448783
234, 12.0, -7.16197243914
274, 12.0, -3.58098621957
290, 12.0, -2.44461992589
1314, 12.0,  2.44461992589
1330, 12.0,  3.58098621957
1370, 12.0,  7.16197243914
1442, 12.0,  14.3239448783
1602, 12.0,  28.6478897565
**
**--------------------------------------+
**  GENERATE NODES OF LINE1S            |~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~#
**--------------------------------------+
**
*NGEN,NSET=LINE1S
2, 162,1
162, 234,1
234, 274,1
274, 290,1
290, 1314,1
1314, 1330,1
1330, 1370,1
1370, 1442,1
1442, 1602,1
**
**---------------------------------------------+
**  GENERATE LINE2S,3&4 USING *NCOPY COMMAND   |~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~#
**---------------------------------------------+
**
*NCOPY,SHIFT,OLD SET=LINE1S,NEW SET=LINE2S,CHANGE NUMBER=3202
-0.002,0,0
0.,0.,0.,0.,0.,1.,0.
**
*NCOPY,SHIFT,OLD SET=LINE1S,NEW SET=LINE3S,CHANGE NUMBER=38424
-0.03,0,0
0.,0.,0.,0.,0.,1.,0.
**
*NCOPY,SHIFT,OLD SET=LINE1S,NEW SET=LINE4S,CHANGE NUMBER=115272
-0.12,0,0
0.,0.,0.,0.,0.,1.,0.
**
*NCOPY,SHIFT,OLD SET=LINE1S,NEW SET=LINE5S,CHANGE NUMBER=281776
-0.48,0,0
0.,0.,0.,0.,0.,1.,0.
**
*NCOPY,SHIFT,OLD SET=LINE1S,NEW SET=LINE6S,CHANGE NUMBER=666016
-9.0,0,0
0.,0.,0.,0.,0.,1.,0.
**
*NCOPY,SHIFT,OLD SET=LINE6S,NEW SET=LINE7S,CHANGE NUMBER=512320
-2.4,0,0
0.,0.,0.,0.,0.,1.,0.
**
**+----------------------------------------------------+
**    NFILL the nodes of the sphere.                   |~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~#
**+----------------------------------------------------+
**
*NFILL,NSET=SPHERE
LINE1S,LINE2S,2, 1601
LINE2S,LINE3S,11, 3202
LINE3S,LINE4S,12, 6404
LINE4S,LINE5S,13, 12808
LINE5S,LINE6S,15, 25616
LINE6S,LINE7S,10, 51232
**
**+----------------------------------------------------+
**    Map nodes of SPHERE from cylindrical coordinates |~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~#
**+----------------------------------------------------+
**
*NSET,NSET=SPHERE
NCenterS
*NMAP,NSET=SPHERE,TYPE=CYLINDRICAL
0.,12.0,0.,0.,12.0,1.
0.,-1.,0.
1.,1.,1.
**
**---------------------------------------------+
**  Generate elements of the SPHERE.           |
**---------------------------------------------+
**
*ELEMENT,ELSET=ZONE1S,TYPE=CPE4
1,290,291,1892,1891
*ELGEN,ELSET=ZONE1S
1,1024,1,1,2,1601,1024
**
*ELEMENT,ELSET=ZONE2S,TYPE=CPE4
2049,274,276,3478,3476
2585,3492,3494,6696,6694
2569,1314,1316,4518,4516
*ELGEN,ELSET=ZONE2S
2049,8,2,1,12,3202,528
2585,512,2,1,11,3202,528
2569,8,2,1,12,3202,528
**
*ELEMENT,ELSET=ZONE3S,TYPE=CPE4
8385,234,238,6642,6638
10099,38698,38702,45106,45102
8659,1330,1334,7738,7734
*ELGEN,ELSET=ZONE3S
8385,10,4,1,18,6404,284
10099,264,4,1,12,6404,284
8659,10,4,1,18,6404,284
**
*ELEMENT,ELSET=ZONE4S,TYPE=CPE4
13497,162,170,12978,12970
14946,115506,115514,128322,128314
13648,1370,1378,14186,14178
*ELGEN,ELSET=ZONE4S
13497,9,8,1,22,12808,160
14946,142,8,1,13,12808,160
13648,9,8,1,22,12808,160
**
*ELEMENT,ELSET=ZONE5S,TYPE=CPE4
17017,2,18,25634,25618
18127,281938,281954,307570,307554
17107,1442,1458,27074,27058
*ELGEN,ELSET=ZONE5S
17017,10,16,1,26,25616,100
18127,80,16,1,15,25616,100
17107,10,16,1,26,25616,100
**
*ELEMENT,ELSET=ZONE6S,TYPE=CPE4
19617,666018,666050,717282,717250
*ELGEN,ELSET=ZONE6S
19617,50,32,1,10,51232,50
**
**
**+-------------------------------------------+
**    define mesh refinement MPCs for SPHERE. |~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~#
**+-------------------------------------------+
**
**  node sets for LINEAR TIE between ZONE1S & ZONE2S
**
*NSET,NSET=NSET1LnrMPCaZ1Z2S,GENERATE
290,290,3202
*NSET,NSET=NSET1LnrMPCbZ1Z2S,GENERATE
3492,3492,3202
*NSET,NSET=NSET1LnrMPCpZ1Z2S,GENERATE
1891,1891,3202
**   1       2
*NSET,NSET=NSET2LnrMPCaZ1Z2S,GENERATE
3492,4514,2
*NSET,NSET=NSET2LnrMPCbZ1Z2S,GENERATE
3494,4516,2
*NSET,NSET=NSET2LnrMPCpZ1Z2S,GENERATE
3493,4515,2
**   1       2
*NSET,NSET=NSET3LnrMPCaZ1Z2S,GENERATE
1314,1314,3202
*NSET,NSET=NSET3LnrMPCbZ1Z2S,GENERATE
4516,4516,3202
*NSET,NSET=NSET3LnrMPCpZ1Z2S,GENERATE
2915,2915,3202
**
**  node sets for LINEAR TIE between ZONE2S & ZONE3S
**
*NSET,NSET=NSET1LnrMPCaZ2Z3S,GENERATE
274,32294,6404
*NSET,NSET=NSET1LnrMPCbZ2Z3S,GENERATE
6678,38698,6404
*NSET,NSET=NSET1LnrMPCpZ2Z3S,GENERATE
3476,35496,6404
**   2       3
*NSET,NSET=NSET2LnrMPCaZ2Z3S,GENERATE
38698,39750,4
*NSET,NSET=NSET2LnrMPCbZ2Z3S,GENERATE
38702,39754,4
*NSET,NSET=NSET2LnrMPCpZ2Z3S,GENERATE
38700,39752,4
**   2       3
*NSET,NSET=NSET3LnrMPCaZ2Z3S,GENERATE
1330,33350,6404
*NSET,NSET=NSET3LnrMPCbZ2Z3S,GENERATE
7734,39754,6404
*NSET,NSET=NSET3LnrMPCpZ2Z3S,GENERATE
4532,36552,6404
**
**  node sets for LINEAR TIE between ZONE3S & ZONE4S
**
*NSET,NSET=NSET1LnrMPCaZ3Z4S,GENERATE
234,102698,12808
*NSET,NSET=NSET1LnrMPCbZ3Z4S,GENERATE
13042,115506,12808
*NSET,NSET=NSET1LnrMPCpZ3Z4S,GENERATE
6638,109102,12808
**   3       4
*NSET,NSET=NSET2LnrMPCaZ3Z4S,GENERATE
115506,116634,8
*NSET,NSET=NSET2LnrMPCbZ3Z4S,GENERATE
115514,116642,8
*NSET,NSET=NSET2LnrMPCpZ3Z4S,GENERATE
115510,116638,8
**   3       4
*NSET,NSET=NSET3LnrMPCaZ3Z4S,GENERATE
1370,103834,12808
*NSET,NSET=NSET3LnrMPCbZ3Z4S,GENERATE
14178,116642,12808
*NSET,NSET=NSET3LnrMPCpZ3Z4S,GENERATE
7774,110238,12808
**
**  node sets for LINEAR TIE between ZONE4S & ZONE5S
**
*NSET,NSET=NSET1LnrMPCaZ4Z5S,GENERATE
162,256322,25616
*NSET,NSET=NSET1LnrMPCbZ4Z5S,GENERATE
25778,281938,25616
*NSET,NSET=NSET1LnrMPCpZ4Z5S,GENERATE
12970,269130,25616
**   4       5
*NSET,NSET=NSET2LnrMPCaZ4Z5S,GENERATE
281938,283202,16
*NSET,NSET=NSET2LnrMPCbZ4Z5S,GENERATE
281954,283218,16
*NSET,NSET=NSET2LnrMPCpZ4Z5S,GENERATE
281946,283210,16
**   4       5
*NSET,NSET=NSET3LnrMPCaZ4Z5S,GENERATE
1442,257602,25616
*NSET,NSET=NSET3LnrMPCbZ4Z5S,GENERATE
27058,283218,25616
*NSET,NSET=NSET3LnrMPCpZ4Z5S,GENERATE
14250,270410,25616
**
**  node sets for LINEAR TIE between ZONE5S & ZONE6S
**
*NSET,NSET=NSET1LnrMPCaZ5Z6S,GENERATE
666018,667586,32
*NSET,NSET=NSET1LnrMPCbZ5Z6S,GENERATE
666050,667618,32
*NSET,NSET=NSET1LnrMPCpZ5Z6S,GENERATE
666034,667602,32
**
*MPC
LINEAR,NSET1LnrMPCpZ1Z2S,NSET1LnrMPCaZ1Z2S,NSET1LnrMPCbZ1Z2S
LINEAR,NSET2LnrMPCpZ1Z2S,NSET2LnrMPCaZ1Z2S,NSET2LnrMPCbZ1Z2S
LINEAR,NSET3LnrMPCpZ1Z2S,NSET3LnrMPCaZ1Z2S,NSET3LnrMPCbZ1Z2S
**
LINEAR,NSET1LnrMPCpZ2Z3S,NSET1LnrMPCaZ2Z3S,NSET1LnrMPCbZ2Z3S
LINEAR,NSET2LnrMPCpZ2Z3S,NSET2LnrMPCaZ2Z3S,NSET2LnrMPCbZ2Z3S
LINEAR,NSET3LnrMPCpZ2Z3S,NSET3LnrMPCaZ2Z3S,NSET3LnrMPCbZ2Z3S
**
LINEAR,NSET1LnrMPCpZ3Z4S,NSET1LnrMPCaZ3Z4S,NSET1LnrMPCbZ3Z4S
LINEAR,NSET2LnrMPCpZ3Z4S,NSET2LnrMPCaZ3Z4S,NSET2LnrMPCbZ3Z4S
LINEAR,NSET3LnrMPCpZ3Z4S,NSET3LnrMPCaZ3Z4S,NSET3LnrMPCbZ3Z4S
**
LINEAR,NSET1LnrMPCpZ4Z5S,NSET1LnrMPCaZ4Z5S,NSET1LnrMPCbZ4Z5S
LINEAR,NSET2LnrMPCpZ4Z5S,NSET2LnrMPCaZ4Z5S,NSET2LnrMPCbZ4Z5S
LINEAR,NSET3LnrMPCpZ4Z5S,NSET3LnrMPCaZ4Z5S,NSET3LnrMPCbZ4Z5S
**
LINEAR,NSET1LnrMPCpZ5Z6S,NSET1LnrMPCaZ5Z6S,NSET1LnrMPCbZ5Z6S
**
**--------------------------------------------------------------------------+
** CONTACT SURFACE DEFINITIONS OF THE SPHERE                                |~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~#
**--------------------------------------------------------------------------+
**
*ELSET,ELSET=ESurfSphere,GENERATE
1,1024,1
2049,2056,1
8385,8394,1
13497,13505,1
17017,17026,1
2569,2576,1
8659,8668,1
13648,13656,1
17107,17116,1
**
*SURFACE,NAME=SurfSphere,TYPE=ELEMENT
ESurfSphere,S1
**
**+--------------------------------------------+
**    define MATERIAL properties of the SPHERE |~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~#
**+--------------------------------------------+
**
*MATERIAL,NAME=SPHERE
*ELASTIC,TYPE=ISOTROPIC
310000.0,0.27
*DENSITY
3900.0
**
*SOLID SECTION,ELSET=Zone1S,MATERIAL=SPHERE
1.0
*SOLID SECTION,ELSET=Zone2S,MATERIAL=SPHERE
1.0
*SOLID SECTION,ELSET=Zone3S,MATERIAL=SPHERE
1.0
*SOLID SECTION,ELSET=Zone4S,MATERIAL=SPHERE
1.0
*SOLID SECTION,ELSET=Zone5S,MATERIAL=SPHERE
1.0
*SOLID SECTION,ELSET=Zone6S,MATERIAL=SPHERE
1.0
*RIGID BODY, REF NODE=NCenterS,POSITION=INPUT,ELSET=Zone6S,DENSITY=2700.
**
**~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~#
**~~~~~~~~~~~~~~~~~~~~~~~~~~~~~########################################~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~#
**~~~~~~~~~~~~~~~~~~~~~~~~~~~~~# ABAQUS INPUT COMMANDS FOR THE PLATE  #~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~#
**~~~~~~~~~~~~~~~~~~~~~~~~~~~~~########################################~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~#
**~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~#
**
**--------------------------------------+
**  DEFINE SEED NODES FOR THE PLATE     |~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~#
**--------------------------------------+
**
**
*NODE,NSET=LINE1P
1181539, -8.0, 0.0
1181859, -6.0, 0.0
1182019, -3.0, 0.0
1182091, -1.5, 0.0
1182131, -0.75, 0.0
1182147, -0.512, 0.0
1183171,  0.512, 0.0
1183187,  0.75, 0.0
1183227,  1.5, 0.0
1183299,  3.0, 0.0
1183459,  6.0, 0.0
1183779,  8.0, 0.0
**
**----------------------------------------+
**  GENERATE NODES OF LINE1P OF THE PLATE |~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~#
**----------------------------------------+
**
*NGEN,NSET=LINE1P
1181539, 1181859,1
1181859, 1182019,1
1182019, 1182091,1
1182091, 1182131,1
1182131, 1182147,1
**
1182147, 1183171,1
1183171, 1183187,1
**
1183187, 1183227,1
1183227, 1183299,1
1183299, 1183459,1
1183459, 1183779,1
**
**---------------------------------------------------------------------+
**  GENERATE LINE2P,LINE3P & LINE4P USING *NCOPY COMMAND FOR THE PLATE |~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~#
**---------------------------------------------------------------------+
**
*NCOPY,SHIFT,OLD SET=LINE1P,NEW SET=LINE2P,CHANGE NUMBER=4482
0.,-0.002,0.
0.,0.,0.,0.,0.,1.,0.
**
*NCOPY,SHIFT,OLD SET=LINE1P,NEW SET=LINE3P,CHANGE NUMBER=53784
0.,-0.03,0.
0.,0.,0.,0.,0.,1.,0.
**
*NCOPY,SHIFT,OLD SET=LINE1P,NEW SET=LINE4P,CHANGE NUMBER=161352
0.,-0.12,0.
0.,0.,0.,0.,0.,1.,0.
**
*NCOPY,SHIFT,OLD SET=LINE1P,NEW SET=LINE5P,CHANGE NUMBER=394416
0.,-0.48,0.
0.,0.,0.,0.,0.,1.,0.
**
*NCOPY,SHIFT,OLD SET=LINE1P,NEW SET=LINE6P,CHANGE NUMBER=788832
0.,-1.92,0.
0.,0.,0.,0.,0.,1.,0.
**
*NCOPY,SHIFT,OLD SET=LINE1P,NEW SET=LINE7P,CHANGE NUMBER=1075680
0.,-7.68,0.
0.,0.,0.,0.,0.,1.,0.
**
**+----------------------------------------------------+
**    NFILL the nodes of the PLATE.                    |~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~#
**+----------------------------------------------------+
**
*NFILL,NSET=PLATE
LINE1P,LINE2P,   2, 2241
LINE2P,LINE3P,11, 4482
LINE3P,LINE4P,12, 8964
LINE4P,LINE5P,13, 17928
LINE5P,LINE6P,11, 35856
LINE6P,LINE7P,4, 71712
**
**+----------------------------------------------------+
**    Map nodes of PLATE from RECTANGULAR coordinates  |~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~#
**+----------------------------------------------------+
**
*NMAP,NSET=PLATE,TYPE=RECTANGULAR
0.,0.,0.,-1.,0.,0.
1.,1.,0.
1.,1.,1.
**-----------------------------------------------+
**  GENERATE ELEMENTS OF MESH ZONES OF THE PLATE |~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~#
**-----------------------------------------------+
** Elements of Zone1P
**
*ELEMENT,ELSET=ZONE1P,TYPE=CPE4
20117,1182147,1182148,1184389,1184388
*ELGEN,ELSET=ZONE1P
20117,1024,1,1,2,2241,1024
**
** Elements of Zone2P
**
*ELEMENT,ELSET=ZONE2P,TYPE=CPE4
22165,1182131,1182133,1186615,1186613
22701,1186629,1186631,1191113,1191111
22685,1183171,1183173,1187655,1187653
*ELGEN,ELSET=ZONE2P
22165,8,2,1,12,4482,528
22701,512,2,1,11,4482,528
22685,8,2,1,12,4482,528
**
** Elements of Zone3P
**
*ELEMENT,ELSET=ZONE3P,TYPE=CPE4
28501,1182091,1182095,1191059,1191055
30215,1235915,1235919,1244883,1244879
28775,1183187,1183191,1192155,1192151
*ELGEN,ELSET=ZONE3P
28501,10,4,1,18,8964,284
30215,264,4,1,12,8964,284
28775,10,4,1,18,8964,284
**
** Elements of Zone4P
**
*ELEMENT,ELSET=ZONE4P,TYPE=CPE4
33613,1182019,1182027,1199955,1199947
35062,1343443,1343451,1361379,1361371
33764,1183227,1183235,1201163,1201155
*ELGEN,ELSET=ZONE4P
33613,9,8,1,22,17928,160
35062,142,8,1,13,17928,160
33764,9,8,1,22,17928,160
**
** Elements of Zone5P
**
*ELEMENT,ELSET=ZONE5P,TYPE=CPE4
37133,1181859,1181875,1217731,1217715
38243,1576435,1576451,1612307,1612291
37223,1183299,1183315,1219171,1219155
*ELGEN,ELSET=ZONE5P
37133,10,16,1,22,35856,100
38243,80,16,1,11,35856,100
37223,10,16,1,22,35856,100
**
** Elements of Zone6P
**
*ELEMENT,ELSET=ZONE6P,TYPE=CPE4
39333,1181539,1181571,1253283,1253251
40113,1970691,1970723,2042435,2042403
39393,1183459,1183491,1255203,1255171
*ELGEN,ELSET=ZONE6P
39333,10,32,1,15,71712,70
40113,50,32,1,4,71712,70
39393,10,32,1,15,71712,70
**
**+-------------------------------------------------------------+
**    Define nodeset for data output along the symmetry axis Y  |~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~#
**+-------------------------------------------------------------+
**
*NSET,NSET=SYMMETRY,GENERATE
1182659 ,1187141 , 2241
1187141 ,1236443 , 4482
1236443 ,1344011 , 8964
1344011 ,1577075 , 17928
1577075 ,1971491, 35856
1971491,2258339, 71712
**
**+-------------------------------------------------------------+
**    Mesh refinement MPCs for the PLATE mesh zones.            |~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~#
**+-------------------------------------------------------------+
**
**  node sets for LINEAR TIE between ZONE1P & ZONE2P
**
*NSET,NSET=NSET1LnrMPCaZ1Z2P,GENERATE
1182147,1182147,4482
*NSET,NSET=NSET1LnrMPCbZ1Z2P,GENERATE
1186629,1186629,4482
*NSET,NSET=NSET1LnrMPCpZ1Z2P,GENERATE
1184388,1184388,4482
**   1       2
*NSET,NSET=NSET2LnrMPCaZ1Z2P,GENERATE
1186629,1187651,2
*NSET,NSET=NSET2LnrMPCbZ1Z2P,GENERATE
1186631,1187653,2
*NSET,NSET=NSET2LnrMPCpZ1Z2P,GENERATE
1186630,1187652,2
**   1       2
*NSET,NSET=NSET3LnrMPCaZ1Z2P,GENERATE
1183171,1183171,4482
*NSET,NSET=NSET3LnrMPCbZ1Z2P,GENERATE
1187653,1187653,4482
*NSET,NSET=NSET3LnrMPCpZ1Z2P,GENERATE
1185412,1185412,4482
**
**  node sets for LINEAR TIE between ZONE2P & ZONE3P
**
*NSET,NSET=NSET1LnrMPCaZ2Z3P,GENERATE
1182131,1226951,8964
*NSET,NSET=NSET1LnrMPCbZ2Z3P,GENERATE
1191095,1235915,8964
*NSET,NSET=NSET1LnrMPCpZ2Z3P,GENERATE
1186613,1231433,8964
**   2       3
*NSET,NSET=NSET2LnrMPCaZ2Z3P,GENERATE
1235915,1236967,4
*NSET,NSET=NSET2LnrMPCbZ2Z3P,GENERATE
1235919,1236971,4
*NSET,NSET=NSET2LnrMPCpZ2Z3P,GENERATE
1235917,1236969,4
**   2       3
*NSET,NSET=NSET3LnrMPCaZ2Z3P,GENERATE
1183187,1228007,8964
*NSET,NSET=NSET3LnrMPCbZ2Z3P,GENERATE
1192151,1236971,8964
*NSET,NSET=NSET3LnrMPCpZ2Z3P,GENERATE
1187669,1232489,8964
**
**  node sets for LINEAR TIE between ZONE3P & ZONE4P
**
*NSET,NSET=NSET1LnrMPCaZ3Z4P,GENERATE
1182091,1325515,17928
*NSET,NSET=NSET1LnrMPCbZ3Z4P,GENERATE
1200019,1343443,17928
*NSET,NSET=NSET1LnrMPCpZ3Z4P,GENERATE
1191055,1334479,17928
**   3       4
*NSET,NSET=NSET2LnrMPCaZ3Z4P,GENERATE
1343443,1344571,8
*NSET,NSET=NSET2LnrMPCbZ3Z4P,GENERATE
1343451,1344579,8
*NSET,NSET=NSET2LnrMPCpZ3Z4P,GENERATE
1343447,1344575,8
**   3       4
*NSET,NSET=NSET3LnrMPCaZ3Z4P,GENERATE
1183227,1326651,17928
*NSET,NSET=NSET3LnrMPCbZ3Z4P,GENERATE
1201155,1344579,17928
*NSET,NSET=NSET3LnrMPCpZ3Z4P,GENERATE
1192191,1335615,17928
**
** node sets for LINEAR TIE between ZONE4P & ZONE5P
**
*NSET,NSET=NSET1LnrMPCaZ4Z5P,GENERATE
1182019,1540579,35856
*NSET,NSET=NSET1LnrMPCbZ4Z5P,GENERATE
1217875,1576435,35856
*NSET,NSET=NSET1LnrMPCpZ4Z5P,GENERATE
1199947,1558507,35856
**   4       5
*NSET,NSET=NSET2LnrMPCaZ4Z5P,GENERATE
1576435,1577699,16
*NSET,NSET=NSET2LnrMPCbZ4Z5P,GENERATE
1576451,1577715,16
*NSET,NSET=NSET2LnrMPCpZ4Z5P,GENERATE
1576443,1577707,16
**   4       5
*NSET,NSET=NSET3LnrMPCaZ4Z5P,GENERATE
1183299,1541859,35856
*NSET,NSET=NSET3LnrMPCbZ4Z5P,GENERATE
1219155,1577715,35856
*NSET,NSET=NSET3LnrMPCpZ4Z5P,GENERATE
1201227,1559787,35856
****
** node sets for LINEAR TIE between ZONE5P & ZONE6P
**
*NSET,NSET=NSET1LnrMPCaZ5Z6P,GENERATE
1181859,1898979,71712
*NSET,NSET=NSET1LnrMPCbZ5Z6P,GENERATE
1253571,1970691,71712
*NSET,NSET=NSET1LnrMPCpZ5Z6P,GENERATE
1217715,1934835,71712
**   5       6
*NSET,NSET=NSET2LnrMPCaZ5Z6P,GENERATE
1970691,1972259,32
*NSET,NSET=NSET2LnrMPCbZ5Z6P,GENERATE
1970723,1972291,32
*NSET,NSET=NSET2LnrMPCpZ5Z6P,GENERATE
1970707,1972275,32
**   5       6
*NSET,NSET=NSET3LnrMPCaZ5Z6P,GENERATE
1183459,1900579,71712
*NSET,NSET=NSET3LnrMPCbZ5Z6P,GENERATE
1255171,1972291,71712
*NSET,NSET=NSET3LnrMPCpZ5Z6P,GENERATE
1219315,1936435,71712
**
**--------------------------------------------------------------------------+
** "LINEAR" type MPCs for mesh transitons between mesh zones of the plate   |~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~#
**--------------------------------------------------------------------------+
*MPC
**
LINEAR,NSET1LnrMPCpZ1Z2P,NSET1LnrMPCaZ1Z2P,NSET1LnrMPCbZ1Z2P
LINEAR,NSET2LnrMPCpZ1Z2P,NSET2LnrMPCaZ1Z2P,NSET2LnrMPCbZ1Z2P
LINEAR,NSET3LnrMPCpZ1Z2P,NSET3LnrMPCaZ1Z2P,NSET3LnrMPCbZ1Z2P
**
LINEAR,NSET1LnrMPCpZ2Z3P,NSET1LnrMPCaZ2Z3P,NSET1LnrMPCbZ2Z3P
LINEAR,NSET2LnrMPCpZ2Z3P,NSET2LnrMPCaZ2Z3P,NSET2LnrMPCbZ2Z3P
LINEAR,NSET3LnrMPCpZ2Z3P,NSET3LnrMPCaZ2Z3P,NSET3LnrMPCbZ2Z3P
**
LINEAR,NSET1LnrMPCpZ3Z4P,NSET1LnrMPCaZ3Z4P,NSET1LnrMPCbZ3Z4P
LINEAR,NSET2LnrMPCpZ3Z4P,NSET2LnrMPCaZ3Z4P,NSET2LnrMPCbZ3Z4P
LINEAR,NSET3LnrMPCpZ3Z4P,NSET3LnrMPCaZ3Z4P,NSET3LnrMPCbZ3Z4P
**
LINEAR,NSET1LnrMPCpZ4Z5P,NSET1LnrMPCaZ4Z5P,NSET1LnrMPCbZ4Z5P
LINEAR,NSET2LnrMPCpZ4Z5P,NSET2LnrMPCaZ4Z5P,NSET2LnrMPCbZ4Z5P
LINEAR,NSET3LnrMPCpZ4Z5P,NSET3LnrMPCaZ4Z5P,NSET3LnrMPCbZ4Z5P
**
LINEAR,NSET1LnrMPCpZ5Z6P,NSET1LnrMPCaZ5Z6P,NSET1LnrMPCbZ5Z6P
LINEAR,NSET2LnrMPCpZ5Z6P,NSET2LnrMPCaZ5Z6P,NSET2LnrMPCbZ5Z6P
LINEAR,NSET3LnrMPCpZ5Z6P,NSET3LnrMPCaZ5Z6P,NSET3LnrMPCbZ5Z6P
**----------------------------------------------------------------------------------+
** GENERATE NODE SET FOR THE APPLICATION OF THE LOAD TO THE LEFT SIDE OF THE SPHERE.|~~~~~~~~~~~~~~~~~~~~~~~~~~~~~#
**----------------------------------------------------------------------------------+
*NSET,NSET=LFTEDGE_S,GENERATE
2, 640402,25616
*NSET,NSET=RGTEDGE_S,GENERATE
1602, 642002,25616
*EQUATION
2
LFTEDGE_S,1,1.0,NCenterS,1,-1.0
2
RGTEDGE_S,1,1.0,NCenterS,1,-1.0
**
2
LFTEDGE_S,2,1.0,NCenterS,2,-1.0
2
RGTEDGE_S,2,1.0,NCenterS,2,-1.0
**-----------------------------------------------------------------------------------+
** GENERATE NODE & ELEMENT SETS FOR THE APPLICATION OF THE LOAD & BC's ON THE PLATE. |~~~~~~~~~~~~~~~~~~~~~~~~~~~~~#
**-----------------------------------------------------------------------------------+
** CREATE NODE_SET LEFT EDGE
*NSET,NSET=LFTEDGE_P,GENERATE
1183779, 2187747,71712
*NSET,NSET=RGTEDGE_P,GENERATE
1253251, 2185507,71712
**
** USE *EQUATION TO APPLY BULK TENSION TO THE RIGHT EDGE OF THE PLATE.
*EQUATION
2
RGTEDGE_P,1,1.0,1181539,1,-1.0
**
*NSET,NSET=NRgtMasterP
1181539
**
**--------------------------------------------------------------------------+
** CONTACT SURFACE DEFINITIONS OF THE PLATE                                 |~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~#
**--------------------------------------------------------------------------+
*ELSET,ELSET=ESurfPlate,GENERATE
20117,21140,1
22165,22172,1
28501,28510,1
33613,33621,1
37133,37142,1
39333,39342,1
**
22685,22692,1
28775,28784,1
33764,33772,1
37223,37232,1
39393,39402,1
**
*SURFACE,NAME=SurfPlate,TYPE=ELEMENT
ESurfPlate,S1
**Fayza
**
*ELSET,ELSET=ESurfBulk,GENERATE
39333,40313,70
*SURFACE,NAME=ESurfBulk,TYPE=ELEMENT
ESurfBulk,S4
**+------------------------------------------------------+
**    define MATERIAL properties of the PLATE substrate  |~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~#
**+------------------------------------------------------+
***MATERIAL,NAME=PLATE
***ELASTIC,TYPE=ISOTROPIC
**210000.0,0.3
***DENSITY
**7800.0
*MATERIAL,NAME=PLATE
*Density
7800.0
*Elastic
210000.0,0.3
***DEFORMATION PLASTICITY
**206.8e3,0.3,170.,4.76,7.42,0
**
***PLASTIC,HARDENING=JOHNSON COOK
**382.0499392,2441.447443,0.655129073,1,0
**    
*PLASTIC
422.66349, 0.00000
430.81336, 0.00100
438.80393, 0.00200
446.64406, 0.00300
454.34181, 0.00400
461.90454, 0.00500
469.33900, 0.00600
476.65141, 0.00700
483.84749, 0.00800
490.93254, 0.00900
497.91146, 0.01000
504.78881, 0.01100
511.56883, 0.01200
518.25547, 0.01300
524.85243, 0.01400
531.36316, 0.01500
537.79090, 0.01600
544.13871, 0.01700
550.40943, 0.01800
556.60577, 0.01900
562.73028, 0.02000
568.78534, 0.02100
574.77324, 0.02200
580.69613, 0.02300
586.55605, 0.02400
592.35492, 0.02500
598.09459, 0.02600
603.77680, 0.02700
609.40323, 0.02800
614.97544, 0.02900
620.49497, 0.03000
625.96324, 0.03100
631.38164, 0.03200
636.75149, 0.03300
642.07404, 0.03400
647.35051, 0.03500
652.58205, 0.03600
657.76977, 0.03700
662.91473, 0.03800
668.01797, 0.03900
673.08046, 0.04000
678.10314, 0.04100
683.08694, 0.04200
688.03271, 0.04300
692.94130, 0.04400
697.81354, 0.04500
702.65019, 0.04600
707.45201, 0.04700
712.21974, 0.04800
716.95408, 0.04900
721.65571, 0.05000
726.32528, 0.05100
730.96344, 0.05200
735.57079, 0.05300
740.14794, 0.05400
744.69546, 0.05500
749.21390, 0.05600
753.70382, 0.05700
758.16573, 0.05800
762.60014, 0.05900
767.00756, 0.06000
771.38845, 0.06100
775.74328, 0.06200
780.07250, 0.06300
784.37656, 0.06400
788.65588, 0.06500
792.91087, 0.06600
797.14194, 0.06700

*SOLID SECTION,ELSET=Zone1P,MATERIAL=PLATE
1.0
*SOLID SECTION,ELSET=Zone2P,MATERIAL=PLATE
1.0
*SOLID SECTION,ELSET=Zone3P,MATERIAL=PLATE
1.0
*SOLID SECTION,ELSET=Zone4P,MATERIAL=PLATE
1.0
*SOLID SECTION,ELSET=Zone5P,MATERIAL=PLATE
1.0
*SOLID SECTION,ELSET=Zone6P,MATERIAL=PLATE
1.0
**
**-----------------------+
** AMPLITUDE DEFINITIONS |
**-----------------------+
**
*Amplitude, name=LoadRamp
0., 0., 1.0,1.
**
*Amplitude, name=BattmRamp
0.00  , 0.00  ,0.25  , 1.00  ,0.50  , 0.00  
**
**+------------------------------------------------------+
**    define SURFACE CONTACT properties.                 |~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~#
**+------------------------------------------------------+
*CONTACT PAIR, INTERACTION=Steel-Steel, FINITE SLIDING
SurfPlate,SurfSphere
**
**
*SURFACE INTERACTION,NAME=Steel-Steel
*FRICTION
**, SLIP TOLERANCE=.005
0.6,
*SURFACE BEHAVIOR, PRESSURE-OVERCLOSURE=EXPONENTIAL
1e-005,721.5
**
**+------------------------------------------------------+
**    define BOUNDARY conditions       .                 |~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~#
**+------------------------------------------------------+
*BOUNDARY,TYPE=DISPLACEMENT
Line7P   ,2,2
LFTEDGE_P,2,2
**
**+------------------------------------------------------+
**    STEP1: APPLY NORMAL LOAD                           |~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~#
**+------------------------------------------------------+
**
*STEP,NAME=APPLY-NORMAL,NLGEOM=NO
*STATIC
**, DIRECT
**,STABILIZE=0.0002
0.25,1.
*BOUNDARY,TYPE=DISPLACEMENT
**Line7P,2,2
NCenterS,1,1
**
*CLOAD
NCenterS,2,-571.5
**
** INTERACTIONS
**
** Contact Controls for Interaction: CylinderPlaneContact
*CONTACT CONTROLS,SLAVE=SURFPLATE,MASTER=SURFSPHERE, AUTOMATICTOLERANCES, STABILIZE=1.
**
**
** OUTPUT REQUESTS FOR STEP1
**
*OUTPUT,HISTORY,FREQUENCY=99
*CONTACT OUTPUT,SLAVE=SurfPlate,MASTER=SurfSphere
CPRESS,CSHEAR1
*CONTACT FILE,SLAVE=SurfPlate,MASTER=SurfSphere,FREQUENCY=1
CAREA
*CONTACT PRINT,SLAVE=SurfPlate,MASTER=SurfSphere,TOTALS=NO,SUMMARY=YES,FREQUENCY=99
**CPRESS,CSHEAR1,CDISP
CAREA
*NODE PRINT, NSET=LINE1P,TOTALS=NO,SUMMARY=YES,FREQUENCY=99
**COORD
*NODE PRINT, NSET= NCenterS,TOTALS=NO,SUMMARY=YES,FREQUENCY=99
RF,CF,U
*OUTPUT,FIELD,FREQUENCY=10,VARIABLE=PRESELECT
*END STEP
**
**+------------------------------------------------------+
**    STEP2: APPLY TANGENTIAL LOAD TO THE LEFT           |~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~#
**+------------------------------------------------------+
**
*STEP, NAME=APPPLY Q,NLGEOM=NO
APPLY TANGENTIAL LOAD.
*STATIC
**,Direct
**,STABILIZE=0.0002
0.1,1.
*BOUNDARY,OP=NEW,TYPE=DISP
Line7P,2,2
LFTEDGE_P,1,1

NCenterS,1,1
***BOUNDARY,OP=NEW,TYPE=DISP, AMPLITUDE=BattmRamp
**Line7P       ,1,1,0.02
**LFTEDGE_P    ,1,1,0.02
**1181539,1,1,0.02
**
*BOUNDARY,OP=NEW,TYPE=DISP
Line7P,2,2
LFTEDGE_P,1,1
**
*CLOAD,OP=MOD, AMPLITUDE=BattmRamp
NCenterS     ,1,-171.45
*DLOAD, AMPLITUDE=BattmRamp
ESurfBulk,P4,-431.6087917
**
**
** INTERACTIONS
**
** Contact Controls for Interaction: CylinderPlaneContact
*CONTACT CONTROLS,SLAVE=SURFPLATE,MASTER=SURFSPHERE, AUTOMATICTOLERANCES, STABILIZE=1.
**
** OUTPUT REQUESTS FOR STEP2
**
*OUTPUT,HISTORY,FREQUENCY=1
*CONTACT OUTPUT,SLAVE=SurfPlate,MASTER=SurfSphere
**CPRESS,CSHEAR1
*NODE OUTPUT, NSET= NCenterS
RF,CF,U
*NODE OUTPUT, NSET= NRgtMasterP
U
*CONTACT FILE,SLAVE=SurfPlate,MASTER=SurfSphere,FREQUENCY=1
CAREA
**CDISP
*CONTACT PRINT,SLAVE=SurfPlate,MASTER=SurfSphere,TOTALS=NO,SUMMARY=YES,FREQUENCY=99
**CPRESS,CSHEAR1,CDISP
CAREA
*NODE PRINT, NSET=LINE1P,TOTALS=NO,SUMMARY=YES,FREQUENCY=99
COORD
*NODE PRINT, NSET= NCenterS,TOTALS=NO,SUMMARY=YES,FREQUENCY=99
RF,CF,U
*NODE PRINT, NSET= NRgtMasterP
U
*OUTPUT,FIELD,VARIABLE=PRESELECT,FREQUENCY=1
*END STEP

Amir Siddiq's picture

Hi,

I had a brief look at your input file. I found few things to mention. You might already know or missed somehow.

- You can't use finite sliding option in Contact Pair. Were you able to successfully run the job with it?
- no contact pair definition was there. I think you missed to define master and slave surface names in the contact pair option.
- you have used contact stabilization option along with model stabilization which is never recommended. Its bit tricky to use them as one has to compare contact damping stresses with contact normal and tangential stresses to check whether contact damping stresses are not high enough. Similarly if you use stabilize option in the step definition then static dissipation of the model has to be compared with the total strain energy of the system to avoid over damped system (which would lead to spurious results). Just a tip! In my experience, one has to do fine tunning of this parameter by making a few runs to come up to a reasonable value of stabilize parameter.

-There is a section in ABAQUS analysis manual which discusses common difficulties associated with contact/interaction models. Please have a look. About fluctuating shear stresses, It states the following 

- By default, tangential contact constraints are applied as soon as contact is established. In most cases, this will yield satisfactory results and reasonable convergence. However, experience has shown that applying the normal constraint in the increment when contact is established and applying the tangential constraints in the subsequent increment can sometimes lead to improved convergence, particularly if frictional stresses have a strong effect on contact stresses.

In such cases you can change the default behavior to delay friction to the increments subsequent to the increment in which a contact point closes. This is not recommended if the contact zone changes rapidly as the analysis progresses; in that case, the absence of friction immediately after closure can lead to rapid, nonphysical oscillations in the frictional forces. This setting applies for all kinds of friction, including rough friction; but it has no effect on user subroutine FRIC, which is called whenever contact occurs at the end of an increment. You can restore the default behavior as needed.

At this moment and the brief look I had, I only came up with the above mentioned points. I will try to look in detail during the weekend and come back meanwhile you can try above mentioned things. May be they will resolve your problem.

All the best.

 

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