# To output element stiffness matrix to a result file **URL:** \ **Category:** Uncategorized\ **Created:** [December 27, 2023, 5:35am UTC](https://calculix.discourse.group/t/to-output-element-stiffness-matrix-to-a-result-file/1988 "2023-12-27T05:35:18Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![Anoop\_ng](https://avatars.discourse-cdn.com/v4/letter/a/4491bb/32.png) [@Anoop\_ng](https://calculix.discourse.group/u/Anoop_ng)\ **Post date:** [December 27, 2023, 5:35am UTC](https://calculix.discourse.group/t/to-output-element-stiffness-matrix-to-a-result-file/1988/1 "2023-12-27T05:35:18Z")
Hello everyone, I’m relatively new to Calculix and currently working on solving a static linear elastic problem. I’ve been trying to find a way to output the **element stiffness matrix** to a result file. Could someone please guide me on whether this is possible and, if so, provide instructions on how to achieve this? Your assistance would be greatly appreciated. Thank you in advance! Anoop ---
**Author:** ![JuanP74](https://avatars.discourse-cdn.com/v4/letter/j/b5a626/32.png) [@JuanP74](https://calculix.discourse.group/u/JuanP74)\ **Post date:** [December 27, 2023, 8:00am UTC](https://calculix.discourse.group/t/to-output-element-stiffness-matrix-to-a-result-file/1988/2 "2023-12-27T08:00:15Z")
you have it explained in the manual (v2.21), along with reference to examples provided with the software: ![imagen](https://global.discourse-cdn.com/free1/uploads/calculix/original/2X/5/53019cbd5d80e3d4dc7c5f7710bfdc206ade69b5.png) ---
**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:** [December 27, 2023, 8:17am UTC](https://calculix.discourse.group/t/to-output-element-stiffness-matrix-to-a-result-file/1988/3 "2023-12-27T08:17:22Z")
This (new) keyword is for substructure usage. To just write a stiffness (and mass) matrix, one can use: `*FREQUENCY, SOLVER=MATRIXSTORAGE` ---
**Author:** ![JuanP74](https://avatars.discourse-cdn.com/v4/letter/j/b5a626/32.png) [@JuanP74](https://calculix.discourse.group/u/JuanP74)\ **Post date:** [December 27, 2023, 10:00am UTC](https://calculix.discourse.group/t/to-output-element-stiffness-matrix-to-a-result-file/1988/4 "2023-12-27T10:00:32Z")
as the problem is linear static > [@Anoop\_ng](#): > > solving a static linear elastic problem I’d recommend `*SUBSTRUCTURE GENERATE` and `*SUBSTRUCTURE MATRIX OUTPUT` for earlier versions of CCX rather than `*FREQUENCY`, all are valid approaches but maybe these are more fitted to the request. ---
**Author:** ![Anoop\_ng](https://avatars.discourse-cdn.com/v4/letter/a/4491bb/32.png) [@Anoop\_ng](https://calculix.discourse.group/u/Anoop_ng)\ **Post date:** [December 27, 2023, 10:13am UTC](https://calculix.discourse.group/t/to-output-element-stiffness-matrix-to-a-result-file/1988/5 "2023-12-27T10:13:45Z")
Does this approach produces element stiffness matrix or the Global stiffness matrix? ---
**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:** [December 27, 2023, 10:19am UTC](https://calculix.discourse.group/t/to-output-element-stiffness-matrix-to-a-result-file/1988/6 "2023-12-27T10:19:27Z")
Conversely, I would recommend `*FREQUENCY, SOLVER=MATRIXSTORAGE`. The stiffness matrix generated by it should be the same as the one used in linear static analysis. Matrices used in substructures can be defined in a different manner, specific to superelements. This applies to both matrix file syntax and concepts (retained nodes in substructures, limitations of substructures and so on). > [@Anoop\_ng](#): > > Does this approach produces element stiffness matrix or the Global stiffness matrix? You will get a global stiffness matrix this way. Abaqus has a `*MATRIX GENERATE` keyword with an optional `ELEMENT BY ELEMENT` parameter to generate local matrices. ---
**Author:** ![Anoop\_ng](https://avatars.discourse-cdn.com/v4/letter/a/4491bb/32.png) [@Anoop\_ng](https://calculix.discourse.group/u/Anoop_ng)\ **Post date:** [December 27, 2023, 11:33am UTC](https://calculix.discourse.group/t/to-output-element-stiffness-matrix-to-a-result-file/1988/7 "2023-12-27T11:33:53Z")
@JuanP74 : using `*SUBSTRUCTURE GENERATE` and `*SUBSTRUCTURE MATRIX OUTPUT` cards produces element stiffness matrix or global stiffness matrix? ---
**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:** [December 27, 2023, 11:36am UTC](https://calculix.discourse.group/t/to-output-element-stiffness-matrix-to-a-result-file/1988/8 "2023-12-27T11:36:21Z")
It produces a global stiffness matrix unless you make a substructure consisting of just a single element. Still, I would be careful with this approach.