Hi there community,
I'm a postgrad student trying to incorporate cohesive friction interaction to model longitudinal fibre debonding in microscale composite materials. In this case, I'm using the full plastic curve for the matrix, which includes softening with a late small hardening and hexagonal carbon fibre packing. While I'm using Abaqus/explicit in order to model this matrix, the contact interaction has been causing all sorts of problems, generating weird interactions with the pressure, stresses and elements getting snagged. I've tried adding and removing dampening (linear, quadratic, contact, damage) to no great avail.
In general terms, I'm using displacement control with a smooth step to load the composite to 2% strain. I've included the images of the pressure on the fibre that is debonding. where the hotspots are located in the direction of neighbouring fibres. A second image shows how, in the later stages, the pressure starts localizing into specific nodes. Which leads to the failure of the analysis due to excessive distortion in these elements. Finally, at the end is the matrix material definition, contact interaction and contact behaviour definition.
At this point, I'm open to any and all ideas and would greatly appreciate your unique perspectives on this matter.
Thank you for your time!
PD: I've reposted this as I previously posted it in the wrong section. Sorry.
Latest stable pressure time increment:
Highly localized pressure on some nodes:
Material configuration:
*Material, name=Matrix-DP
*Density
1.2e-09,
*Drucker Prager
4.39,1.,0.
*Drucker Prager Hardening
85.602, 0.
90.4183, 0.00255205
94.6874, 0.00510409
98.554, 0.00765614
101.987, 0.0102082
104.958, 0.0127602
107.536, 0.0153123
109.667, 0.0178643
111.411, 0.0204164
112.822, 0.0229684
113.87, 0.0255205
114.627, 0.0280725
115.125, 0.0306246
115.386, 0.0331766
115.409, 0.0357287
115.267, 0.0382807
114.932, 0.0408327
114.437, 0.0433848
113.837, 0.0459368
113.093, 0.0484889
112.274, 0.0510409
111.409, 0.053593
110.455, 0.056145
109.468, 0.0586971
108.514, 0.0612491
107.508, 0.0638012
106.496, 0.0663532
105.53, 0.0689053
104.555, 0.0714573
103.598, 0.0740094
102.668, 0.0765614
101.806, 0.0791134
100.93, 0.0816655
100.094, 0.0842175
99.3154, 0.0867696
98.5534, 0.0893216
97.8236, 0.0918737
97.1179, 0.0944257
96.4818, 0.0969778
95.8625, 0.0995298
95.2592, 0.102082
94.6944, 0.104634
94.1818, 0.107186
93.6882, 0.109738
93.2118, 0.11229
92.7551, 0.114842
92.3556, 0.117394
91.957, 0.119946
91.5779, 0.122498
91.2332, 0.12505
90.9199, 0.127602
90.6119, 0.130154
90.325, 0.132706
90.0533, 0.135258
89.7949, 0.137811
89.5405, 0.140363
89.3225, 0.142915
89.1159, 0.145467
88.9146, 0.148019
88.7337, 0.150571
88.5569, 0.153123
88.3882, 0.155675
88.2252, 0.158227
88.0688, 0.160779
87.9343, 0.163331
87.813, 0.165883
87.6869, 0.168435
87.5656, 0.170987
87.4397, 0.173539
87.3292, 0.176091
87.2235, 0.178643
87.1161, 0.181195
87.0312, 0.183747
86.9494, 0.186299
86.8708, 0.188851
86.7973, 0.191403
86.7179, 0.193956
86.6535, 0.196508
86.6011, 0.19906
86.5384, 0.201612
86.4856, 0.204164
86.4386, 0.206716
86.3971, 0.209268
86.342, 0.21182
86.2954, 0.214372
86.2516, 0.216924
86.2145, 0.219476
86.1766, 0.222028
86.1543, 0.22458
86.1269, 0.227132
86.1038, 0.229684
86.0791, 0.232236
86.0533, 0.234788
86.0343, 0.23734
86.0205, 0.239892
86.0089, 0.242444
85.9905, 0.244996
85.9774, 0.247549
85.9612, 0.250101
85.9497, 0.252653
85.9336, 0.255205
85.9197, 0.257757
85.9125, 0.260309
85.8932, 0.262861
85.8778, 0.265413
85.876, 0.267965
85.8658, 0.270517
85.8643, 0.273069
85.8719, 0.275621
85.8613, 0.278173
85.8473, 0.280725
85.8405, 0.283277
85.8395, 0.285829
85.8295, 0.288381
85.8238, 0.290933
85.8227, 0.293485
85.8133, 0.296037
85.8016, 0.298589
85.796, 0.301142
85.7858, 0.303694
85.7883, 0.306246
85.772, 0.308798
85.7546, 0.31135
85.7478, 0.313902
85.7491, 0.316454
85.73, 0.319006
85.7203, 0.321558
85.7121, 0.32411
85.6904, 0.326662
85.6745, 0.329214
85.6659, 0.331766
85.6547, 0.334318
85.6397, 0.33687
85.6271, 0.339422
85.6178, 0.341974
85.615, 0.344526
85.6141, 0.347078
85.5972, 0.34963
85.5826, 0.352182
85.5739, 0.354734
85.5557, 0.357287
85.5407, 0.359839
85.5332, 0.362391
85.5195, 0.364943
85.5132, 0.367495
85.5283, 0.370047
85.5286, 0.372599
85.5213, 0.375151
85.5303, 0.377703
85.542, 0.380255
85.5458, 0.382807
85.5615, 0.385359
85.5807, 0.387911
85.6082, 0.390463
85.6336, 0.393015
85.6499, 0.395567
85.6643, 0.398119
85.6856, 0.400671
85.7094, 0.403223
85.7352, 0.405775
85.7668, 0.408327
85.8077, 0.41088
85.8578, 0.413432
85.9058, 0.415984
85.9524, 0.418536
86.0058, 0.421088
86.0627, 0.42364
86.1165, 0.426192
86.1802, 0.428744
86.2485, 0.431296
86.3209, 0.433848
86.3983, 0.4364
86.4767, 0.438952
86.5561, 0.441504
86.647, 0.444056
86.7392, 0.446608
86.8255, 0.44916
86.9232, 0.451712
87.0143, 0.454264
87.1148, 0.456816
87.2099, 0.459368
87.3198, 0.46192
87.4331, 0.464472
87.5535, 0.467025
87.6717, 0.469577
87.7932, 0.472129
87.9163, 0.474681
88.0357, 0.477233
88.1633, 0.479785
88.2827, 0.482337
88.4187, 0.484889
88.5505, 0.487441
88.687, 0.489993
88.826, 0.492545
88.973, 0.495097
89.1176, 0.497649
89.2655, 0.500201
89.4152, 0.502753
89.5516, 0.505305
89.6774, 0.507857
89.8103, 0.510409
89.9553, 0.512961
90.1156, 0.515513
90.2722, 0.518065
90.4475, 0.520618
90.6106, 0.52317
90.7635, 0.525722
90.9243, 0.528274
91.0839, 0.530826
91.2435, 0.533378
91.4024, 0.53593
91.5788, 0.538482
91.7504, 0.541034
91.9225, 0.543586
92.096, 0.546138
92.2704, 0.54869
92.4448, 0.551242
92.6202, 0.553794
92.7923, 0.556346
92.9645, 0.558898
93.1392, 0.56145
93.3214, 0.564002
93.51, 0.566554
93.6995, 0.569106
93.8864, 0.571658
94.0712, 0.57421
94.2723, 0.576763
94.4568, 0.579315
94.653, 0.581867
94.8496, 0.584419
95.0392, 0.586971
95.2276, 0.589523
95.4202, 0.592075
95.6106, 0.594627
95.814, 0.597179
96.0211, 0.599731
96.2244, 0.602283
96.4334, 0.604835
96.633, 0.607387
96.8356, 0.609939
97.0447, 0.612491
97.2596, 0.615043
97.4694, 0.617595
97.685, 0.620147
97.8975, 0.622699
98.1024, 0.625251
98.3245, 0.627803
98.549, 0.630356
98.7734, 0.632908
99.0051, 0.63546
99.2286, 0.638012
99.4746, 0.640564
99.7019, 0.643116
99.9289, 0.645668
100.162, 0.64822
100.394, 0.650772
100.618, 0.653324
100.848, 0.655876
101.081, 0.658428
101.325, 0.66098
101.558, 0.663532
101.792, 0.666084
102.043, 0.668636
102.288, 0.671188
102.532, 0.67374
102.778, 0.676292
103.007, 0.678844
103.261, 0.681396
103.487, 0.683948
103.728, 0.686501
103.993, 0.689053
104.246, 0.691605
104.509, 0.694157
104.772, 0.696709
105.044, 0.699261
105.317, 0.701813
105.57, 0.704365
105.837, 0.706917
106.097, 0.709469
106.366, 0.712021
106.633, 0.714573
106.887, 0.717125
107.176, 0.719677
107.453, 0.722229
107.727, 0.724781
108.003, 0.727333
108.274, 0.729885
108.547, 0.732437
108.818, 0.734989
109.093, 0.737541
109.37, 0.740094
109.64, 0.742646
109.917, 0.745198
110.181, 0.74775
110.474, 0.750302
110.773, 0.752854
111.069, 0.755406
111.367, 0.757958
111.652, 0.76051
111.963, 0.763062
112.255, 0.765614
112.549, 0.768166
112.857, 0.770718
113.153, 0.77327
113.464, 0.775822
113.763, 0.778374
114.076, 0.780926
114.399, 0.783478
114.716, 0.78603
115.042, 0.788582
115.353, 0.791134
115.667, 0.793686
115.982, 0.796239
116.319, 0.798791
116.659, 0.801343
116.965, 0.803895
117.29, 0.806447
117.619, 0.808999
117.974, 0.811551
118.3, 0.814103
118.651, 0.816655
119.005, 0.819207
119.36, 0.821759
119.718, 0.824311
120.067, 0.826863
120.432, 0.829415
120.804, 0.831967
121.165, 0.834519
121.525, 0.837071
121.876, 0.839623
122.234, 0.842175
122.596, 0.844727
122.965, 0.847279
123.318, 0.849832
123.679, 0.852384
124.058, 0.854936
124.46, 0.857488
124.843, 0.86004
125.243, 0.862592
125.649, 0.865144
126.047, 0.867696
126.424, 0.870248
126.79, 0.8728
127.173, 0.875352
127.563, 0.877904
127.945, 0.880456
128.319, 0.883008
128.708, 0.88556
129.112, 0.888112
129.518, 0.890664
129.926, 0.893216
130.325, 0.895768
130.727, 0.89832
131.154, 0.900872
131.593, 0.903424
132.027, 0.905977
132.469, 0.908529
132.879, 0.911081
133.301, 0.913633
133.721, 0.916185
134.129, 0.918737
134.55, 0.921289
134.999, 0.923841
135.4, 0.926393
135.795, 0.928945
136.185, 0.931497
136.526, 0.934049
136.946, 0.936601
137.394, 0.939153
137.833, 0.941705
138.265, 0.944257
138.686, 0.946809
139.119, 0.949361
139.568, 0.951913
140.045, 0.954465
140.414, 0.957017
140.814, 0.95957
141.216, 0.962122
141.591, 0.964674
141.938, 0.967226
142.349, 0.969778
142.822, 0.97233
143.321, 0.974882
143.798, 0.977434
144.252, 0.979986
144.656, 0.982538
145.098, 0.98509
145.287, 0.987642
145.338, 0.990194
145.552, 0.992746
145.677, 0.995298
146.004, 0.99785
146.386, 1.0004
146.825, 1.00295
147.282, 1.00551
147.731, 1.00806
147.512, 1.01061
147.502, 1.01316
147.817, 1.01571
148.282, 1.01827
148.216, 1.02082
148.097, 1.02337
148.312, 1.02592
148.659, 1.02847
149.075, 1.03103
149.52, 1.03358
150.087, 1.03613
150.624, 1.03868
151.049, 1.04124
151.581, 1.04379
152.121, 1.04634
152.691, 1.04889
153.247, 1.05144
153.804, 1.054
154.35, 1.05655
*Elastic
3395.5, 0.405
*Expansion
6.25e-05,
Contact interaction definition:
*Surface Interaction, name=coh
*Friction
0.3,
*Surface Behavior, pressure-overclosure=HARD
*Cohesive Behavior
*Damage Initiation, criterion=MAXS
60.,60.,60.
*Damage Evolution, type=ENERGY
100.,
*Contact Damping, definition=CRITICAL DAMPING FRACTION
1.0,
**
** INTERACTIONS
**
** Interaction: coh-int
*Contact, op=NEW
*Contact Inclusions, ALL EXTERIOR
*Contact Property Assignment
, , empty
Part-3-1.M-surf , Part-4-1.F-surf , coh
*CONTACT CONTROLS ASSIGNMENT, TYPE=SCALE PENALTY
Part-3-1.M-surf , Part-4-1.F-surf , 0.5
*Contact Mass Scaling, Location=SPECIFIED SURFACES
Part-3-1.M-surf, Part-4-1.F-surf
