# The coupling calculation diverged at first time step, which is based on overInterDyMFoam and Calculix **URL:** \ **Category:** Using preCICE\ **Tags:** openfoam, data-mapping, calculix, fsi\ **Created:** [October 6, 2022, 5:46am UTC](https://precice.discourse.group/t/the-coupling-calculation-diverged-at-first-time-step-which-is-based-on-overinterdymfoam-and-calculix/1171 "2022-10-06T05:46:31Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![O\_K](https://yyz2.discourse-cdn.com/free1/user_avatar/precice.discourse.group/o_k/32/1340_2.png) [@O\_K](https://precice.discourse.group/u/O_K)\ **Post date:** [October 6, 2022, 5:46am UTC](https://precice.discourse.group/t/the-coupling-calculation-diverged-at-first-time-step-which-is-based-on-overinterdymfoam-and-calculix/1171/1 "2022-10-06T05:46:31Z")
In order to insert the overset into my simulation, I’m using preCICE to couple overInterDymFoam and Calculix. Now, the connection between overInterDyMFoam and Calculix has been bulit successfully. But the case diverged at first time step. Then I check the .frd file of Calculix and find that displacement is infinite and force is very large at first time step. I think that the problem may occur on the data mapping. But I’m not familiar with the data mapping. Could you help me and provide the idea to fix it? The case is presented here [https://github.com/NUGUY2022/overset\_preCICE\_multiphase.git](https://github.com/NUGUY2022/overset_preCICE_multiphase.git) ---
**Author:** ![Makis](https://yyz2.discourse-cdn.com/free1/user_avatar/precice.discourse.group/makis/32/25_2.png) [@Makis](https://precice.discourse.group/u/Makis)\ **Post date:** [October 6, 2022, 7:14am UTC](https://precice.discourse.group/t/the-coupling-calculation-diverged-at-first-time-step-which-is-based-on-overinterdymfoam-and-calculix/1171/2 "2022-10-06T07:14:25Z")
Your mapping looks correct to me: ![precice-config](https://global.discourse-cdn.com/free1/uploads/precice/original/2X/d/d982742d8dd6a4fd254eaad89dc13946e160ea96.png) In the [`debug_OpenFOAM.log`](https://github.com/NUGUY2022/overset_preCICE_multiphase/blob/main/debug_OpenFOAM.log), I read `Receive using sockets failed with system error: read: End of file`. This usually means that the other participant crashed. In the [`debug_Solid.log`](https://github.com/NUGUY2022/overset_preCICE_multiphase/blob/main/debug_Solid.log), however, I don’t see any error. Where is the output of CalculiX itself? If you compare your case to the perpendicular flap tutorial, what is different? ---
**Author:** ![O\_K](https://yyz2.discourse-cdn.com/free1/user_avatar/precice.discourse.group/o_k/32/1340_2.png) [@O\_K](https://precice.discourse.group/u/O_K)\ **Post date:** [October 9, 2022, 6:22am UTC](https://precice.discourse.group/t/the-coupling-calculation-diverged-at-first-time-step-which-is-based-on-overinterdymfoam-and-calculix/1171/3 "2022-10-09T06:22:53Z")
Sorry for late to reply. These are ouput and force of Calculix. ![force_calculix](https://global.discourse-cdn.com/free1/uploads/precice/original/2X/f/ff5aff7fdabc131f042726f1a75b1f434fb031e7.png) ![output_calculix](https://global.discourse-cdn.com/free1/uploads/precice/original/2X/5/52b7516859b9080556588b2b96942cad70a1dc67.png) I modify the dambreak case of this link [tutorials/FSI/flap\_perp/OpenFOAM-CalculiX\_interFoam at master · Alphaoo1/tutorials (github.com)](https://github.com/Alphaoo1/tutorials/tree/master/FSI/flap_perp/OpenFOAM-CalculiX_interFoam). This case can run well. ---
**Author:** ![Makis](https://yyz2.discourse-cdn.com/free1/user_avatar/precice.discourse.group/makis/32/25_2.png) [@Makis](https://precice.discourse.group/u/Makis)\ **Post date:** [October 11, 2022, 7:56am UTC](https://precice.discourse.group/t/the-coupling-calculation-diverged-at-first-time-step-which-is-based-on-overinterdymfoam-and-calculix/1171/4 "2022-10-11T07:56:14Z")
I don’t have any good ideas right now, maybe someone else could help here. ---
**Author:** ![O\_K](https://yyz2.discourse-cdn.com/free1/user_avatar/precice.discourse.group/o_k/32/1340_2.png) [@O\_K](https://precice.discourse.group/u/O_K)\ **Post date:** [October 11, 2022, 11:28am UTC](https://precice.discourse.group/t/the-coupling-calculation-diverged-at-first-time-step-which-is-based-on-overinterdymfoam-and-calculix/1171/5 "2022-10-11T11:28:29Z")
Thank you! I’m looking forward to getting other’s help. ---
**Author:** ![jiayu\_sun](https://yyz2.discourse-cdn.com/free1/user_avatar/precice.discourse.group/jiayu_sun/32/1750_2.png) [@jiayu\_sun](https://precice.discourse.group/u/jiayu_sun)\ **Post date:** [June 8, 2023, 3:56am UTC](https://precice.discourse.group/t/the-coupling-calculation-diverged-at-first-time-step-which-is-based-on-overinterdymfoam-and-calculix/1171/6 "2023-06-08T03:56:36Z")
I am also interested in the overInterDyMFoam and CalculiX coupling through preCICE, did you finally get your problem solved? 😀 ---
**Author:** ![O\_K](https://yyz2.discourse-cdn.com/free1/user_avatar/precice.discourse.group/o_k/32/1340_2.png) [@O\_K](https://precice.discourse.group/u/O_K)\ **Post date:** [June 13, 2023, 7:51am UTC](https://precice.discourse.group/t/the-coupling-calculation-diverged-at-first-time-step-which-is-based-on-overinterdymfoam-and-calculix/1171/7 "2023-06-13T07:51:17Z")
In my opinion, it is because the overset mesh in my case is connected with the bottom boundary. If the overset mesh is in the domain and not connected with the boundary, maybe it works well. But I didn’t test it. You can try it.