Відео

Hello, I am sorry but I don't understand your question. Can you rephrase it?

@@LearnFiniteElementAnalysis I mean if the there is a stepped bar loaded axially. can it be modelled axisymetricaly and as a 2D plane?

@@cadinsider964 It certainly can be modelling asymmetrically but a 2D plane either assumes plane stress (with zero stress through the plane) or plane strain (with zero strain through the plane) - neither of these would be correct if you just took a slice through a stepped bar loaded axially.

Glad it was helpful!

Thanks! I am glad it was useful to you

Hi, for some elements (like beam and truss elements) it is not possible to directly get the vonMises stress as their formulation is not based on 3D stress and strain but rather on a truss or a beam formulation. For these elements we are typically more interested in axial stress or bending stress. It is, however, possible to create user defined results to manipulate the results as I show in this video: ua-cam.com/video/LByOz8U1aLk/v-deo.html

Hi, in this case the block has a height of 0.1m to we are moving the top die down by 0.025m as this is 25% of 0.1m. Hope this helps!

thank you sir@@LearnFiniteElementAnalysis

Hi. This is not readily available in workbench. You would have to calculate it (more or less following the method that I show in the video). The hydrostatic stress gradient is basically the ratio of the difference between the stress values of two consecutives nodes to the distance between the nodes, so you would have to do calculations on all of these.

Hi, the negative values indicate compressive stress/strain while the positive values are tensile. The reason I am ignoring them is that, if you take a look, you will see that the negative values are (at least) an order of magnitude smaller than the positive values. For example, at time 36:00 in the video, the max tensile stress is 3e7 Pa while the max compressive stress is -6.7e5 Pa. Hope this helps.

Hi Kyle, thanks for your kind comments - I'm really glad the book was of help to you!

I bought one we can share it if you want <3

@@guillaumerouffignac4718 yes senpai UwU

Hi, do you mean these ones: ua-cam.com/users/GlasnevinPublishingvideos They are a bit out of date and I plan to update them and post them to this channel.

@@LearnFiniteElementAnalysis yes those were the ones....thank you 😊😊

Hi, you would use the same method shown in the video but select the three principal *strains* instead of the stresses (as I showed in the video). Hope this helps.

Glad it helped!

Hi. it's possible to get a good mesh, or even the same mesh, with both methods

Hi, as far as I am aware, it is not directly available. You would have to calculate it from other values in a similar manner as I have shown in the video

Hi, that error message is basically saying to you that your model is unconstrained in the z-direction and can move as much as it wants in the z-direction. Clearly this is a 2D model and should only have degrees of freedom (DOF) in the x and y directions. I suspect what has happened is that you forgot the step early in the video where you set the analysis type to a 2D analysis!

@@LearnFiniteElementAnalysis thanks alot for your help actually it was because the file name should be in English and i was using German letters so that was the problem

Hi, in general stress analysis (not just FEA) the maximum principal stress is always S1 and the minimum is always S3 - this is a convention that is always used in stress analysis. So, if you had three stresses, say: 300 MPa 200 MPa and -400MPa then S1=300MPa S2=200MPA and S3=-400MPa.

@@LearnFiniteElementAnalysis is there some datasheet prepared by ANSYS that defines these expressions?

Thanks!

No problem - glad you found it useful! If we applied a fixed support then the nodes that make up the edge of the plate would not be able to move in any direction. We want these nodes to be able to slide along the line that we have added the boundary conditions to - so that the plate can change shape due to the applied load. If we applied a fixed support instead then the plate would not deform properly. Hope this makes sense?

Symmetry should be not only in geometry but also in loading. Keeping this in mind you can try make a symmetric model if possible.

Yes, you are correct. In order to use axisymmetry (or indeed any other type of symmetry) both the geometry and loads must be symmetric about the axis of symmetry.

ANSYS Classic/APDL has a method called "harmonic axisymmetric" that allows you to apply non-axisymmetric loads to a standard looking axisymmetric model. The element formulation is adjusted to allow this behavior. The term harmonic is confusing to many because the harmonic refers to Fourier coefficients used to define the non-symmetric loads. Harmonic here does not mean dynamic or time-changing.

Hi, I am not sure what you mean here. The bicycle problem is 3D so you could use 3D solid elements instead of beam elements if you wanted but I am not sure how or why you would use 2D elements to accurately model this problem

Hi, glad you liked it! It is possible to apply a rotational velocity to axisymmetric elements in workbench. If you open up the help system and go to the verification manual and look up VM-WB-MECH-062 "Stresses in a Long Cylinder" you will see an example of how to do this. Otherwise, I think you would need to use ANSYS APDL (i.e. the "classic" interface to ANSYS) in order to be able to use torsional loads on axisymmetric elements.

Hi, it's possible that the lines making the outer square are not joined together - there may be a small gap between them. Try checking this and see if it helps!

Hi, any of the commercially available software's are good! ANSYS workbench is reasonably easy to learn how to use which makes it quite popular.

You are welcome! I haven't done a lot of work with ACP recently so I don't remember all of the intricacies but two things come to mind: 1) are you sure that your geometry is defined on the xy plane and not another plane? 2) did you make sure to select a 2D analysis at the start? - if it is expecting a 3D analysis then it may be forcing the cyclic option.

Glad it was helpful!

That is great - I am glad you like it! Thanks for the feedback.

Glad it was helpful!

Hi, that normally isn't a problem. If you click on mesh again then the mesh should be redisplayed. Sometimes workbench turns off the display of the mesh to make it easier for you to pick geometrical features when applying loads etc.

Glad it was helpful! Thanks for the comment.

Glad it helped! Thanks.

The error message is telling you that your model is underconstrained and is moving around in space. If you did this in 3D then I am guessing that you put the symmetry constraints in the x and y axis but you also need to put at least one constraint in the z-direction.

Glad you liked it!