# UCS Test in PFC2D **URL:** \ **Category:** PFC\ **Created:** [April 7, 2022, 3:41am UTC](https://forum.itascainternational.com/t/ucs-test-in-pfc2d/416 "2022-04-07T03:41:25Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![syaniliffa](https://avatars.discourse-cdn.com/v4/letter/s/57b2e6/32.png) [@syaniliffa](https://forum.itascainternational.com/u/syaniliffa)\ **Post date:** [April 7, 2022, 3:41am UTC](https://forum.itascainternational.com/t/ucs-test-in-pfc2d/416/1 "2022-04-07T03:41:25Z")
Dear all, On ucs test using PFC2D, side wall will be removed. How to derive the lateral strain from the test results? Your answer will mean a lot to me, thank you in advance. ---
**Author:** ![dblanksma](https://avatars.discourse-cdn.com/v4/letter/d/858c86/32.png) [@dblanksma](https://forum.itascainternational.com/u/dblanksma)\ **Post date:** [April 7, 2022, 1:51pm UTC](https://forum.itascainternational.com/t/ucs-test-in-pfc2d/416/2 "2022-04-07T13:51:28Z")
Hello Syani, In this case I would use measurement spheres to find the lateral strain. You can review the description of the measurement sphere here - [Measure — PFC 7.0 documentation](http://docs.itascacg.com/pfc700/pfc/docproject/source/manual/general_components/measure/measure.html?node2935). Another possibility is to use “gage balls”. This concepts identifies certain balls in the assembly and keeps track of their relative displacements to measure strain. Gage balls are not a command in PFC, but have been implemented with FISH - [Rock Testing — PFC 7.0 documentation](http://docs.itascacg.com/pfc700/pfc/docproject/source/manual/examples/examples/rocktest/rocktest.html?node3472) (scroll to the bottom of the page, ss\_gage.fis is the FISH function). ---
**Author:** ![syaniliffa](https://avatars.discourse-cdn.com/v4/letter/s/57b2e6/32.png) [@syaniliffa](https://forum.itascainternational.com/u/syaniliffa)\ **Post date:** [April 8, 2022, 5:09am UTC](https://forum.itascainternational.com/t/ucs-test-in-pfc2d/416/3 "2022-04-08T05:09:53Z")
Thank you very much for your answer, Sir. Can you give me an example how to use the command? I have tried with the following command, but no result comes out. ![image](https://canada1.discourse-cdn.com/flex031/uploads/itasca/original/1X/813d42e49e84b027600b2f9c538319a1fcfebee0.png) And, what should I do to bring up the history of stress vs strain? I have tried to replace the x-axis with a strain, but the results that appear are still steps. ![image](https://canada1.discourse-cdn.com/flex031/uploads/itasca/original/1X/8c16cd84c56406b1b2a2523d101c20a3f73df9ff.png) Thank you ---
**Author:** ![dblanksma](https://avatars.discourse-cdn.com/v4/letter/d/858c86/32.png) [@dblanksma](https://forum.itascainternational.com/u/dblanksma)\ **Post date:** [April 11, 2022, 4:33pm UTC](https://forum.itascainternational.com/t/ucs-test-in-pfc2d/416/4 "2022-04-11T16:33:16Z")
For your function defined as lateral\_strain\_gage. It loops through all the measurement spheres (circles in 2D) and writes the x-component of the strain rate tensor to “lateral\_strain\_gage”. You can create a history for this with the command: `fish history name <'str'> lateral_strain_gage` However, since you are using measurement sphere’s, you do not need to make a function to write to a history. Meaurement sphere’s have history logic built in. See - [measure history command — FLAC3D 7.0 documentation](http://docs.itascacg.com/flac3d700/pfc/pfcmodule/doc/manual/measure_manual/command_reference/cmd_measure/cmd_measure.history.html?node5511) As for specifying the x-axis values, rather than the timestep, you can type in the histories name in the **Vs** field. Here is an example where the name is simply “1” and it becomes the x-axis of on the chart: ![image](https://canada1.discourse-cdn.com/flex031/uploads/itasca/original/1X/fd9010dd6091c5e05124c9a0f3c7efb9e75b3505.png) ---
**Author:** ![syaniliffa](https://avatars.discourse-cdn.com/v4/letter/s/57b2e6/32.png) [@syaniliffa](https://forum.itascainternational.com/u/syaniliffa)\ **Post date:** [April 12, 2022, 5:51am UTC](https://forum.itascainternational.com/t/ucs-test-in-pfc2d/416/5 "2022-04-12T05:51:06Z")
Thanks for the explanation. I have tried to use measure history but it doesn’t work. I tried measuring the lateral strain using a gauge like the one on [Rock Testing — FLAC3D 7.0 documentation](http://docs.itascacg.com/flac3d700/pfc/docproject/source/manual/examples/examples/rocktest/rocktest.html?node6045) by replacing the top and bottom sides with right and left. Can I ask for a review, am I doing it right? I’m worried that I made the wrong script. Here is the script that I use. ![image](https://canada1.discourse-cdn.com/flex031/uploads/itasca/original/1X/9de7970ef98865e1785cda0393da339fbac7cf5e.png) ---
**Author:** ![dblanksma](https://avatars.discourse-cdn.com/v4/letter/d/858c86/32.png) [@dblanksma](https://forum.itascainternational.com/u/dblanksma)\ **Post date:** [April 12, 2022, 1:16pm UTC](https://forum.itascainternational.com/t/ucs-test-in-pfc2d/416/6 "2022-04-12T13:16:12Z")
Hello Syani, Yes, we can review your code. Send your data files to [PFCsupport@itascacg.com](mailto:PFCsupport@itascacg.com). ---
**Author:** ![syaniliffa](https://avatars.discourse-cdn.com/v4/letter/s/57b2e6/32.png) [@syaniliffa](https://forum.itascainternational.com/u/syaniliffa)\ **Post date:** [April 12, 2022, 1:41pm UTC](https://forum.itascainternational.com/t/ucs-test-in-pfc2d/416/7 "2022-04-12T13:41:55Z")
Okay, thank you for your help