# PFC 2D :How to apply the smooth joint contact between different groups in PFC2D 6.00.25 version **URL:** \ **Category:** PFC\ **Tags:** fish, suggestions\ **Created:** [February 8, 2022, 7:51pm UTC](https://forum.itascainternational.com/t/pfc-2d-how-to-apply-the-smooth-joint-contact-between-different-groups-in-pfc2d-6-00-25-version/222 "2022-02-08T19:51:55Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![xiongyu](https://avatars.discourse-cdn.com/v4/letter/x/da6949/32.png) [@xiongyu](https://forum.itascainternational.com/u/xiongyu)\ **Post date:** [February 8, 2022, 7:51pm UTC](https://forum.itascainternational.com/t/pfc-2d-how-to-apply-the-smooth-joint-contact-between-different-groups-in-pfc2d-6-00-25-version/222/1 "2022-02-08T19:51:55Z")
How to apply the smooth joint contact between different groups in PFC2D 6.00.25 version? (Please the attached) . ![01163dbb1d5dba7e2ac3fda1fdf11a6](https://canada1.discourse-cdn.com/flex031/uploads/itasca/original/1X/0aae98456f7bd759e071badb72af12b641a347aa.jpeg) I know "contact groupbehavior " command in PFC2D 6.00.13 version can realize this goal. But the command is not availabe in the PFC2D 6.00.25 version. ---
**Author:** ![dblanksma](https://avatars.discourse-cdn.com/v4/letter/d/858c86/32.png) [@dblanksma](https://forum.itascainternational.com/u/dblanksma)\ **Post date:** [February 10, 2022, 3:33pm UTC](https://forum.itascainternational.com/t/pfc-2d-how-to-apply-the-smooth-joint-contact-between-different-groups-in-pfc2d-6-00-25-version/222/2 "2022-02-10T15:33:00Z")
Hello Xiongyu, The command **contact groupbehavior** was replaced by the _matches_ keyword available in the _range group_ logic. [Here](http://docs.itascacg.com/pfc600/common/module/doc/manual/range_manual/range_commands/rangephrasereference.html?node1152#kwd:range.group) is a description of the keyword. An example of distinguishing contacts between different object groups is provided in “Using the CMAT” tutorial. You can find this tutorial [here](http://docs.itascacg.com/pfc600/pfc/docproject/source/manual/examples/tutorials/using_cmat/using_cmat.html?node5201). Scroll to the section called “Using Additional Slots” It explains how to use the matches keyword to distinguish contacts based on group types. ---
**Author:** ![xiongyu](https://avatars.discourse-cdn.com/v4/letter/x/da6949/32.png) [@xiongyu](https://forum.itascainternational.com/u/xiongyu)\ **Post date:** [February 10, 2022, 8:45pm UTC](https://forum.itascainternational.com/t/pfc-2d-how-to-apply-the-smooth-joint-contact-between-different-groups-in-pfc2d-6-00-25-version/222/3 "2022-02-10T20:45:45Z")
Hello dblanksma Thank you for this useful information. ---
**Author:** ![eneszengin](https://yyz1.discourse-cdn.com/flex031/user_avatar/forum.itascainternational.com/eneszengin/32/58_2.png) [@eneszengin](https://forum.itascainternational.com/u/eneszengin)\ **Post date:** [July 9, 2024, 5:41pm UTC](https://forum.itascainternational.com/t/pfc-2d-how-to-apply-the-smooth-joint-contact-between-different-groups-in-pfc2d-6-00-25-version/222/4 "2024-07-09T17:41:55Z")
> [@dblanksma](#): > > sing Additional Slots” Hi, I was following CMAT tutorial but had a problem with it. I’m using example files to perform a UCS test and apply a smoothjoint model to the group of balls located in a horizontally centred group of balls. When I assign the smoothjoint model to this group, all other contacts “disappears”, and the model starts to fall apart. What am I missing? Thanks! ![PFC_Cmat](https://canada1.discourse-cdn.com/flex031/uploads/itasca/original/2X/8/8e1a4a0bd4e4a9321694d9680d06bc3ebc620284.png) ---
**Author:** ![dblanksma](https://avatars.discourse-cdn.com/v4/letter/d/858c86/32.png) [@dblanksma](https://forum.itascainternational.com/u/dblanksma)\ **Post date:** [July 11, 2024, 3:04pm UTC](https://forum.itascainternational.com/t/pfc-2d-how-to-apply-the-smooth-joint-contact-between-different-groups-in-pfc2d-6-00-25-version/222/5 "2024-07-11T15:04:49Z")
@eneszengin, It’s difficult to say what the problem is exactly. I suggest sending your model to [pfcsupport@itascacg.com](mailto:pfcsupport@itascacg.com). ---
**Author:** ![eneszengin](https://yyz1.discourse-cdn.com/flex031/user_avatar/forum.itascainternational.com/eneszengin/32/58_2.png) [@eneszengin](https://forum.itascainternational.com/u/eneszengin)\ **Post date:** [July 11, 2024, 3:30pm UTC](https://forum.itascainternational.com/t/pfc-2d-how-to-apply-the-smooth-joint-contact-between-different-groups-in-pfc2d-6-00-25-version/222/6 "2024-07-11T15:30:49Z")
Thanks for the reply. I will ask them. By the way, do you know what is the best way to assign new contact models to a specific group of balls? ---
**Author:** ![dblanksma](https://avatars.discourse-cdn.com/v4/letter/d/858c86/32.png) [@dblanksma](https://forum.itascainternational.com/u/dblanksma)\ **Post date:** [July 11, 2024, 3:46pm UTC](https://forum.itascainternational.com/t/pfc-2d-how-to-apply-the-smooth-joint-contact-between-different-groups-in-pfc2d-6-00-25-version/222/7 "2024-07-11T15:46:21Z")
Yes, the best way to assign contact models based on ball groups is to use the range logic with the _group_ and _matches_ keywords. An example of this for the cmat is given in [Inclusions in a Matrix - PFC 7.0](https://docs.itascacg.com/pfc700/pfc/docproject/source/manual/examples/tutorials/inclusions/inclusions.html?node3453) ![image](https://canada1.discourse-cdn.com/flex031/uploads/itasca/original/2X/5/5c28b7e4f9df089cddc232a7549c2840edefc7da.png) The same range logic can be applied to existing contacts with the **contact model** command. ---
**Author:** ![eneszengin](https://yyz1.discourse-cdn.com/flex031/user_avatar/forum.itascainternational.com/eneszengin/32/58_2.png) [@eneszengin](https://forum.itascainternational.com/u/eneszengin)\ **Post date:** [July 11, 2024, 4:04pm UTC](https://forum.itascainternational.com/t/pfc-2d-how-to-apply-the-smooth-joint-contact-between-different-groups-in-pfc2d-6-00-25-version/222/8 "2024-07-11T16:04:27Z")
To be honest, I was trying the same with the codes between _“Lines 24 and 28”_ but probably made some mistakes. As you know, when you use a material modelling support package, all balls come with the same contact model, and I tried to change some of the contacts between _“range group”_ but failed. I will try it again.