Discussion ClosedThis 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.

Structural mechanics_ 2D plane stress problem

Please login with a confirmed email address before reporting spam

Hi all,

I am trying to run a simulations in which the geometry is 2D and it consists of a rectangular shape with slots in the middle. to make it simpler , lets just consider it as a rectangular sheet with some thickness. Refer to attached figure. A displacement is applied on the top edge while constraining the bottom edge in all directions. the right edge is a line of symmetry as the rectangle is considered symmetrical about that line (just to cut down the size and memory while solving).

I want to model this as a elasto-plastic material and it should follow a multi-linear stress-strain curve rather than a bilinear. the values of the multi-linear curve are known.

I want to apply a prescribed value of displacement in the upward and downward direction (tensile and compressive) alternatively. this is generally to generate a hysteresis curve for the model.

please suggest me on :

1. how to provide the Kinematic hardening multi-linear stress strain curve values to define the material model.

2. the procedure in which i can apply the alternating tensile and compressive displacements in the top end.



3 Replies Last Post 2009年8月28日 GMT+2 16:00

Please login with a confirmed email address before reporting spam

Posted: 2 decades ago 2009年8月26日 GMT+2 00:03
Hi:

It's possible to define your own stress-strain curve. Just add a function (Options->Functions...) and tabulate your S-S data in there. With that, you'll have a plot of your material behavior. Once you have that, you can add a scalar expression for the hardening function. That should cover it. There's a very good tutorial for this on the Structural Mechanics Module's User Guide, Chapter 4, page 122. In there you can see a step-by-step guide of how to do it.

As for the alternating loading, you could use a transient analysis with a time-dependent sinusoidal wave for the displacement, or a function with alternating values, or maybe a parametric analysis that uses the previous solution as the starting point for the next iteration.

I hope this was the answer you needed.
Hi: It's possible to define your own stress-strain curve. Just add a function (Options->Functions...) and tabulate your S-S data in there. With that, you'll have a plot of your material behavior. Once you have that, you can add a scalar expression for the hardening function. That should cover it. There's a very good tutorial for this on the Structural Mechanics Module's User Guide, Chapter 4, page 122. In there you can see a step-by-step guide of how to do it. As for the alternating loading, you could use a transient analysis with a time-dependent sinusoidal wave for the displacement, or a function with alternating values, or maybe a parametric analysis that uses the previous solution as the starting point for the next iteration. I hope this was the answer you needed.

Please login with a confirmed email address before reporting spam

Posted: 2 decades ago 2009年8月28日 GMT+2 01:41
hey............


Thanks a lot for the suggestion.................... I would certainly try the simulation this way...........
hey............ Thanks a lot for the suggestion.................... I would certainly try the simulation this way...........

Please login with a confirmed email address before reporting spam

Posted: 2 decades ago 2009年8月28日 GMT+2 16:00
hi,

since you are using this module, i'd like to ask if you are familiar with the difference between the first, second, and third principal stresses is. I know that principal stress is the eigenvalue of the stress matrix, but I don't get what those three pertain to.

Thanks in advance!
hi, since you are using this module, i'd like to ask if you are familiar with the difference between the first, second, and third principal stresses is. I know that principal stress is the eigenvalue of the stress matrix, but I don't get what those three pertain to. Thanks in advance!

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

Baidu
map