Direct shear test
Dear sir
Iam modeling direct shear test by edem software. After I received the generic shear test model from developer of software, I changed the python code for this model to a python code proper for direct shear test. So the difference between direct shear test and generic shear test is that shear for direct shear test occurs in a interface between two boxes of samples moving along each other but generic shear test occurs in all the sample. I send the apparatus for direct shear test and the definition of python code for shear stress in appendix . My problem is that can I define the shear stress in direct shear test like the line defined in python code for generic shear test? Second problem is that when I increase static friction in particles, shear stress decreases that is not compatible by static friction definition. If someone can reply me really appreciate.
Hi Abbas,
You should be able to use the same methods to calculate the stress, however if the stress is calculated in a specific area you may need to then edit the code to just look at the specific region of interest. There is further infomation on editing Python in the EDEM help - https://2022.help.altair.com/2022.2/EDEM/EDEMpy/EDEMpy_Introduction.htm
There are a few reasons that increasing static friction may decrease the stress. It could be the stability of the model, if you have a high friction value the model could be unstable which typically results in lower stress. To confirm this it is best to run at a lower time-step and also to look at the system energy when there is no external inputs like motion, the material should all be at rest.
Regards
Stephen