Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

Using Matrix Transform with Principal Strain Tensor For Principal Strains along Force Application Direction

Please login with a confirmed email address before reporting spam

Hello,

I am running a solid mechanics study with a body load being applied with the total force load type option, defining values for Fx, Fy, and Fz. After running the study, I want to analyze the principal strains, but specifically along the direction of the applied body load, which here is along the unit vector (-0.91755, -0.35177, -0.18536).

My thought is that I can use the Matrix Transform function in COMSOL to transform the principal strain tensor so that one of the principal strain directions is now along the force application direction.

However, I am confused on how to use the Matrix Transform variable utility. I am assuming my input would be Component 1 --> Solid Mechanics --> Strain --> Strain tensor (material and geometry frames) --> solid.e. However, how do I then use this to transform to the wanted direction? I don't see any input for a transform option like inputting a transformation matrix. Any assistance would be helpful.

Note I am using Linux OS if that makes a difference


2 Replies Last Post Mar 1, 2022, 8:32 a.m. EST
Jeff Hiller COMSOL Employee

Please login with a confirmed email address before reporting spam

Posted: 3 years ago Feb 28, 2022, 4:29 p.m. EST

Hello Coleman,

I'll refer you to Henrik's post in your earlier thread. No amount of matrix manipulation can change the direction of principal strains.

Best,

Jeff

-------------------
Jeff Hiller
Hello Coleman, I'll refer you to Henrik's post in [your earlier thread](https://www.comsol.com/forum/thread/304112/finding-the-principal-strain-along-the-direction-of-the-force-applied?last=2022-02-17T21:48:42Z). No amount of matrix manipulation can change the direction of principal strains. Best, Jeff

Please login with a confirmed email address before reporting spam

Posted: 3 years ago Mar 1, 2022, 8:32 a.m. EST

Hello Coleman,

I'll refer you to Henrik's post in your earlier thread. No amount of matrix manipulation can change the direction of principal strains.

Best,

Jeff

Hi Jeff thanks for the answer! After not hearing back, I was hoping for some more information on implementing using the matrix transformation in accordance with the coordinate system corresponding to the force direction.

>Hello Coleman, > >I'll refer you to Henrik's post in [your earlier thread](https://www.comsol.com/forum/thread/304112/finding-the-principal-strain-along-the-direction-of-the-force-applied?last=2022-02-17T21:48:42Z). No amount of matrix manipulation can change the direction of principal strains. > >Best, > >Jeff Hi Jeff thanks for the answer! After not hearing back, I was hoping for some more information on implementing using the matrix transformation in accordance with the coordinate system corresponding to the force direction.

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.