# Question on tracking the number of subcontacts experiencing sliding or dilation at different iteration steps **URL:** \ **Category:** 3DEC\ **Created:** [January 17, 2024, 6:58am UTC](https://forum.itascainternational.com/t/question-on-tracking-the-number-of-subcontacts-experiencing-sliding-or-dilation-at-different-iteration-steps/1297 "2024-01-17T06:58:01Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![JLUJYP](https://avatars.discourse-cdn.com/v4/letter/j/9f8e36/32.png) [@JLUJYP](https://forum.itascainternational.com/u/JLUJYP)\ **Post date:** [January 17, 2024, 6:58am UTC](https://forum.itascainternational.com/t/question-on-tracking-the-number-of-subcontacts-experiencing-sliding-or-dilation-at-different-iteration-steps/1297/1 "2024-01-17T06:58:01Z")
How can I monitor the subcontact states (sliding, dilation, etc.) of joint sets in 3DEC 7.0? I want to track the number of subcontacts experiencing sliding or dilation at different iteration steps in the model. Thank you very much! ---
**Author:** ![Theophile](https://yyz1.discourse-cdn.com/flex031/user_avatar/forum.itascainternational.com/theophile/32/299_2.png) [@Theophile](https://forum.itascainternational.com/u/Theophile)\ **Post date:** [January 17, 2024, 9:39am UTC](https://forum.itascainternational.com/t/question-on-tracking-the-number-of-subcontacts-experiencing-sliding-or-dilation-at-different-iteration-steps/1297/2 "2024-01-17T09:39:15Z")
Hi @JLUJYP ! You could use the [`fish history`](https://docs.itascacg.com/3dec700/common/kernel/doc/manual/fish/commands/cmd_fish.history.html#fish.history) command. In PS of this message, I give a script modified after the [slip.dat](https://docs.itascacg.com/3dec700/3dec/docproject/source/theory/mohrcoulomb/mohrcoulomb.html) file from 3DEC documentation. When plotting the history at the end of the run, I get this result for the number of sliding points (cyan line in the picture): ![image](https://canada1.discourse-cdn.com/flex031/uploads/itasca/original/1X/91e294e23a74d841bf75d42c7cffbb1a099746cd.png) The key points are: - setting a Fish function to keep track of number of subcontacts (3DEC command `fish define nsliding_nodes`in script below) - setting the interval history with the 3DEC `history interval` command - setting the actual tracking with the 3DEC `fish history name` command You can then customize the subcontacts states you want to keep track of with other state values (see the **States** section in link above). Notice that `history command` lets you track values on regular intervals. You can also base your tracking on _events_ rather than on regular intervals (_e.g._, each time a subcontact enters sliding), see the [`fish callback`](https://docs.itascacg.com/3dec700/common/kernel/doc/manual/fish/commands/cmd_fish.callback.html?node1585) 3DEC command. Hope it helps! Regards Théophile PS : the script ```auto ; Example from 3DEC documentation, modified to keep track of number of sliding/ruptured joints ; doc/3dec/docproject/source/theory/mohrcoulomb/mohrcoulomb.html model new model large-strain on ; Coulomb slip joint model ; direct shear test ; block create brick -0.15,0.15 -0.10,0.10 -0.10,0 block create brick -0.10,0.10 -0.10,0.10 0,0.10 block zone generate edgelength 0.02 block zone cmodel assign elastic block zone prop dens=0.0026 bulk=4000 shear=3000 ; ; Coulomb slip model block contact jmodel assign mohr block contact prop stiffness-normal=100000 stiffness-shear=100000 ... friction=30.0 dilation 15 dilation-zero 6e-4 ;; Use cohesion for weakening behavior ;block contact prop cohesion 10 block contact material-table default prop stiffness-normal=100000 ... stiffness-shear=100000 ... friction=30.0 dilation 15 ... dilation-zero 6e-4 block hide range pos-z 0 1 block gridpoint apply vel 0 0 0 range pos-z -1 0.1 block hide off ; ; normal load block face apply stress 0 0 -50 0 0 0 range pos-z 0.1 ; model cycle 100 fish define nsliding_nodes ; Compute number of sliding nodes local nnodes = 0 loop foreach local cpnt block.contact.list() loop foreach local cxpnt block.contact.subcontactlist(cpnt) local sliding_now = math.and(block.subcontact.state(cxpnt), 1) if sliding_now nnodes += 1 end_if end_loop end_loop nsliding_nodes = nnodes end ; block contact reset disp block contact reset state ; shear load block hide range pos-z -.1 0.0 block gridpoint apply vel-x=0.005 range pos-z -.1 1.1 block gridpoint apply vel-y 0 range pos-z -1 1 block hide off ; his interval 5 fish hist name 'N sliding' nsliding_nodes model cyc 30000 ;model save 'slip1' program return ``` ---
**Author:** ![JLUJYP](https://avatars.discourse-cdn.com/v4/letter/j/9f8e36/32.png) [@JLUJYP](https://forum.itascainternational.com/u/JLUJYP)\ **Post date:** [January 17, 2024, 12:47pm UTC](https://forum.itascainternational.com/t/question-on-tracking-the-number-of-subcontacts-experiencing-sliding-or-dilation-at-different-iteration-steps/1297/3 "2024-01-17T12:47:41Z")
Thank you for your kind response. The information you provided has been very helpful to me. Wishing you a joyful life! ---
**Author:** ![Theophile](https://yyz1.discourse-cdn.com/flex031/user_avatar/forum.itascainternational.com/theophile/32/299_2.png) [@Theophile](https://forum.itascainternational.com/u/Theophile)\ **Post date:** [January 17, 2024, 1:50pm UTC](https://forum.itascainternational.com/t/question-on-tracking-the-number-of-subcontacts-experiencing-sliding-or-dilation-at-different-iteration-steps/1297/4 "2024-01-17T13:50:57Z")
I’m glad it helped! Regards Théophile