# 8 integration points in dat using cps3 and cps4 elements for plane stress **URL:** \ **Category:** Postprocessing/Visualization\ **Created:** [May 9, 2025, 5:45am UTC](https://calculix.discourse.group/t/8-integration-points-in-dat-using-cps3-and-cps4-elements-for-plane-stress/2735 "2025-05-09T05:45:00Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![Paulo](https://avatars.discourse-cdn.com/v4/letter/p/bbce88/32.png) [@Paulo](https://calculix.discourse.group/u/Paulo)\ **Post date:** [May 9, 2025, 5:45am UTC](https://calculix.discourse.group/t/8-integration-points-in-dat-using-cps3-and-cps4-elements-for-plane-stress/2735/1 "2025-05-09T05:45:00Z")
Hey, I understand for 2d analysis ccx converts the model to 3d, however looking at the dat file i have non zero stress in the z direction. how can i control the integration points. This is my output. \*MATERIAL,NAME=steel \*ELASTIC, TYPE=ISOTROPIC 200000, 0.3 \*DENSITY 7750 \*SOLID SECTION, ELSET=ALL\_ELEMENTS, MATERIAL=steel \*BOUNDARY base\_nodes,2,0 2,1,2,0 \*STEP \*STATIC, SOLVER=SPOOLES \*BOUNDARY displacement\_nodes,2,1 \*EL PRINT,ELSET=ALL\_ELEMENTS S,E,ENER \*NODE PRINT,NSET=ALL\_NODES U \*NODE PRINT,NSET=base\_nodes RF \*NODE FILE,GLOBAL=YES U,RF \*EL FILE S,E,ENER \*END STEP and an example of my elements 1353, 1410, 1423, 1438, 1447 \*ELEMENT, type=CPS3, ELSET=Surface4002 1354, 1, 178, 1463 1355, 1, 1463, 1464 1356, 1, 1464, 1465 1357, 1, 1465, 1466 1358, 1, 1466, 1467 1359, 1, 1467, 142 \*ELEMENT, type=CPS4, ELSET=Surface4002 1360, 178, 179, 1468, 1463 1361, 1463, 1468, 1469, 1464 thank you ---
**Author:** ![Calc\_em](https://avatars.discourse-cdn.com/v4/letter/c/43a26b/32.png) [@Calc\_em](https://calculix.discourse.group/u/Calc_em)\ **Post date:** [May 9, 2025, 7:03am UTC](https://calculix.discourse.group/t/8-integration-points-in-dat-using-cps3-and-cps4-elements-for-plane-stress/2735/2 "2025-05-09T07:03:08Z")
CPS3 is expanded to C3D6 (linear wedge) so it has 2 integration points. CPS4 is expanded to C3D8 (linear hexahedron) so it has 8 integration points. Indeed those elements may have non-zero stresses in the thickness direction: [Discrepancy in Element Stiffness Matrix Output using Substructure Approach - #29 by vicmw](https://calculix.discourse.group/t/discrepancy-in-element-stiffness-matrix-output-using-substructure-approach/2007/29) ---
**Author:** ![Paulo](https://avatars.discourse-cdn.com/v4/letter/p/bbce88/32.png) [@Paulo](https://calculix.discourse.group/u/Paulo)\ **Post date:** [May 9, 2025, 8:22am UTC](https://calculix.discourse.group/t/8-integration-points-in-dat-using-cps3-and-cps4-elements-for-plane-stress/2735/3 "2025-05-09T08:22:48Z")
Thank you for the information and link, is there a method to output the element stress tensor? Or a method to know the coordinatos of the element integration points? ---
**Author:** ![Calc\_em](https://avatars.discourse-cdn.com/v4/letter/c/43a26b/32.png) [@Calc\_em](https://calculix.discourse.group/u/Calc_em)\ **Post date:** [May 9, 2025, 8:35am UTC](https://calculix.discourse.group/t/8-integration-points-in-dat-using-cps3-and-cps4-elements-for-plane-stress/2735/4 "2025-05-09T08:35:34Z")
This will write integration point coordinates and stress tensor components to the .dat file: ```auto *EL PRINT, ELSET=elset_name COORD, S ``` ---
**Author:** ![Paulo](https://avatars.discourse-cdn.com/v4/letter/p/bbce88/32.png) [@Paulo](https://calculix.discourse.group/u/Paulo)\ **Post date:** [May 9, 2025, 9:24am UTC](https://calculix.discourse.group/t/8-integration-points-in-dat-using-cps3-and-cps4-elements-for-plane-stress/2735/5 "2025-05-09T09:24:42Z")
Thank you, \*WARNING reading \*EL PRINT: label not applicable or unknown; \*ERROR reading \*EL PRINT. Card image: COORD,S,E,ENER is this a common error? ---
**Author:** ![Calc\_em](https://avatars.discourse-cdn.com/v4/letter/c/43a26b/32.png) [@Calc\_em](https://calculix.discourse.group/u/Calc_em)\ **Post date:** [May 9, 2025, 10:04am UTC](https://calculix.discourse.group/t/8-integration-points-in-dat-using-cps3-and-cps4-elements-for-plane-stress/2735/6 "2025-05-09T10:04:49Z")
Is it defined lexactly like this (of course, the elset name can be different) ? ```auto *EL PRINT, ELSET=EALL COORD,S,E,ENER ``` This syntax is correct and shouldn’t cause any errors. Maybe you have a typo somewhere (e.g. in ELSET). Is the keyword placed within the step definition (between \*STEP and \*END STEP keywords) ? ---
**Author:** ![Paulo](https://avatars.discourse-cdn.com/v4/letter/p/bbce88/32.png) [@Paulo](https://calculix.discourse.group/u/Paulo)\ **Post date:** [May 10, 2025, 1:06am UTC](https://calculix.discourse.group/t/8-integration-points-in-dat-using-cps3-and-cps4-elements-for-plane-stress/2735/7 "2025-05-10T01:06:04Z")
yeah I am not sure, it works fine without coord. Unless you can see anything in this? \*STEP \*STATIC, SOLVER=SPOOLES \*BOUNDARY displacement\_nodes,2,1 \*EL PRINT,ELSET=ALL\_ELEMENTS COORD,S,E,ENER \*NODE PRINT,NSET=ALL\_NODES U \*NODE PRINT,NSET=base\_nodes RF \*NODE FILE,GLOBAL=YES U,RF \*EL FILE S,E,ENER \*END STEP ---
**Author:** ![Paulo](https://avatars.discourse-cdn.com/v4/letter/p/bbce88/32.png) [@Paulo](https://calculix.discourse.group/u/Paulo)\ **Post date:** [May 10, 2025, 1:35am UTC](https://calculix.discourse.group/t/8-integration-points-in-dat-using-cps3-and-cps4-elements-for-plane-stress/2735/8 "2025-05-10T01:35:40Z")
Could it be the installed version of CCX i am currently using the bconverged ccx 2.10 [Download bConverged](https://www.bconverged.com/download.php#calculix)? ---
**Author:** ![Paulo](https://avatars.discourse-cdn.com/v4/letter/p/bbce88/32.png) [@Paulo](https://calculix.discourse.group/u/Paulo)\ **Post date:** [May 10, 2025, 3:50am UTC](https://calculix.discourse.group/t/8-integration-points-in-dat-using-cps3-and-cps4-elements-for-plane-stress/2735/9 "2025-05-10T03:50:43Z")
I updated CCX, works fine. thanks for the help