Cervenka Consulting Forums — Loading

Re: Loading

2022-12-22T10:31:57Z

Please send your problem to cervenka@cervenka.cz

Thanks
Mohamad

Re: Loading

2022-09-28T15:39:36Z

Hello,

I hope it's no problem, if I refer to this Post as I am facing similar difficulties.

I am trying to model a four Point Bending Beam made from FRC. I am using Gid Science in combination with ATENA Studio and "Cementious 2 user" as material model. The Model is a 3D Beam.
My first attempt was similar to the 2D Tutorial for FRC. I applied the same displacement on each loading plate. As the main Crack didn't developed symetricaly I got positive Forces in one of the boundary plates (Which wouldn't happen in reality)

Now I tried to model the beam of the Testing machine, which is able to rotate and therefore a uneven displacement of the loading plates is possible and therefore no pulling at the boundary loading plate can happen.

I tried to model the hinge by the conection of the beam of the testing machine with the loading plates via "fixed contact for line".

When I am trying to run the analysis now a warning message in Gid appears: "

',4MPa' Expected identifier at position 1
Warning: Some selection of condition Fixed_Contact_for_ MASTER has zero size. ContactName =Prüfmaschine links
Warning: Some selection of condition Fixed_Contact_for_ MASTER has zero size. ContactName =Prüfmaschine rechts
Warning: Some selection of condition Fixed_Contact_for_ SLAVE has zero size. ContactName =Prüfmaschine links
Warning: Some selection of condition Fixed_Contact_for_ SLAVE has zero size. ContactName =Prüfmaschine rechts
Info: Input file was written and is executed in AtenaStudio

Moreover ATENA Studio won't start at all, stating:
"Can not Start analysis - Input file was not specified or doesn't exist"

I would highly apreciate your help. Thanks in advance.

Nils Rittel

Re: Loading

2020-03-30T15:53:25Z

Dear ali, as already explained, if you seek help with your particular modelling, please follow Troubleshooting, 2.1.1 to send us your model etc. - above all, sketches illustrating how the load distribution steel girder can move.

If 2 equal forces are the best approximation, you can apply 2 force loads and use the Arc Length solution method, see also Troubleshooting, 2.4.6.1.

Alternatively, you can include the girder in your model, and apply a single prescribed displacement.

Regards.

Re: Loading

2020-03-30T09:13:53Z

Thank you for your response,

The load from the test machine was transferred through a stiff steel girder onto the test beam in the form of two equally concentrated loads. Means single piston

Regards

Re: Loading

2020-03-30T06:25:13Z

Dear ali,
if you seek help/advice/comment related to your particular model, please follow ATENA Troubleshooting, 2.1.1 to send us your model along with information about what you are modelling (sketches/photos+explanation).

In this case, it is important how the load is distributed in the experiment - 2 pistons with the same pressure? A single piston + some distribution beam (how much free or blocked are its rotations)? 2 pistons with identical displacement? Something else?

Regards.

Loading

2020-03-27T22:05:16Z

Hello, we have this beam mode that we are trying to analyse. Its a four point bending test. But if we put two plates on top of the beam, at the end of the analysis the two loads are not equal, which theoretically should be equal. So we have put another plate at the top of the two plates and applied the load over that one single plate so that the distribution of the load is equal. We are concerned if this method of load application valid? For clearance, the screen shot of the model is attached.

https://drive.google.com/open?id=1nKpFO … BeZ-c5BI5W

Thank you to all in anticipation, have a good day