Interface type to be given


Hi,
I have to give a interface between a surface and a block. The block is on the surface . Initial velocity is given to the block. Can you suggest what Interface type has to be used between block and the surface?
Thanks in advance.

Hi Raghav,
It seems that you want to study the motion of the block over a fixed surface. For this you can go for using TYPE 7 interface with friction value if required between surface and the block. Are you using RBODY for block and giving imposed velocity to master node RBODY?


Hi Gopal,
Yes I'm using RBODY amd IMPACC actually for the block. I guess Type 2 interface is not suitable as well because it is typically used as tied interface(for eg spot welds). I am using type 7 interface. Also when I run my job. It's showing 0 errors however the output file is not getting generated. Only the restart files are generated...
What could be problem??


Hi Raghav,
Check the time step of the model. If possible please share the model files (_0000.rad and _0001.rad) for better understanding.


/VERS/130
/RUN/1910/0/
0.120000000000000
/ANIM/ELEM/EPSP
/ANIM/ELEM/VONM
/ANIM/MASS
/ANIM/DT
0.000000000000000 1.00000000000000E-03
/TFILE/0
1.00000000000000E-03
/ANIM/NODA/DT
/ANIM/NODA/DMAS
/ANIM/NODA/DINER
/DT/BRICK/CST
0.670000000000000 4.00000000000000E-07
/DT/INTER/DEL
0.670000000000000 5.00000000000000E-07
/DT/NODA/CST/0
0.670000000000000 5.00000000000000E-07


Hi Raghav,
In the engine file provided in the above post, the scale factor for imposing a time step is 0.9.
/DT/NODA/CST
0.9 5E-7
Please clarify the same for all.
For a workaround please share your model file (_0000.rad) through the dropbox link provided in the signature. Also please attach the starter out file (_0000.out)


Hi,
Thnaks for the advice.. I decreased the time step and its working. However if in the animation The base nodes of the blocks are getting attached to the surface. Could you specify why??
I used a type 2 interface between cube and surface, pulse is given to the center node of the cube(made it RBODY). and the surface is stationery.


Hi Raghav,
For better understanding need to review the model.Meanwhile can you try running the analysis with Type 7 interface and update.

Hi Kash,
TYPE 2 is a tied interface and thus will not allow relative motion. TYPE 7 is a general contact which will take sliding if happening into account. So, go for TYPE 7 contact between the surfaces and also friction value if available.
Also for time step first run the model with no imposed time step option i.e DT/NODA commands , with this you will be able to know the natural time step and based on that value imposed time step is defined. If you have already done this, ignore this.
Hi Raghav,
You can try modeling this contact using TYPE2 tied interface that kinematically connects a set of slave nodes to a master surface.
Please visit this link which give more details on Type 2 interface: http://www.altairuniversity.com/learning-library/vii_b_interface-type-2-in-radioss/