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crushing of honeycomb

Dear George,

Thank you for the reply. I have used LAW27 as material model with failure strain of 0.15. I want to plot the time history plot of total load coming onto hemishpere. Experimental value is near to 120kg . I could see option of nodal and elemetal contact force but summing the all nodal contact forces i am not getting in hyperview.

Can you tell me how to sum up the forces coming on to hemisphere during each load step. I have attached the file for your reference.

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Altair Forum User

Hi Rajeev,

You can create an output block for that interface (hemisphere-structure) and can try to output the plot.

Another workarounds are, if your hemisphere is rigid, you can plot the time history for those rigid elements. Else you can try to create a cross section in the hemisphere, and can create an output block for the same.

Altair Forum User

Dear George,

I have tried to simulate contact using RWALL option . I created a rigid sphere (RWALL) and imposed a constant velocity on the sphere. Slave nodes I have choosen the Sandwich panel in RWALL option. Top,bottom facesheet is connected with honeycomb through TYPE -2 Contact. During Checking process in RADIOSS I am getting warning message of INCOMPATIBLE KINEMATIC CONSTRAINT. While the job still runs but during simulation in each step ERR comes out to be -99.9%. Time history plot of RWALL is generated . In the simulation i can see the large irregular behavior of elements when sphere comes out of bottom facesheet. Can you pls let me know why this is happening.

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Altair Forum User

Hi Rajeev,

Rigid wall is a non-yielding retaining wall. They are used to define an interface between a rigid surface and nodes of a deformable body.

I recommend you to create a rigid sphere and define the contact between the structure and sphere and run the analysis.

Meanwhile I will update you on this very soon.

Altair Forum User

Dear George ,

Thanks for the reply. Some of the elements outside the contact area are showing more than 20mm deflection. It is happening when the projectile is coming out of the Back facsheet. I have attached the Image for your reference.

I have asked for Normal force on the impactor during the process through TH card available in radioss. Time history plot shows the reduction of load when the front facheet breaks but it doesnot show any thing for back facheet rupture. Ideally when the impactor hits the back facheet the load should increase , The load increase will have till the point of rupture of second facheet after that the load should reduce. This phenomenon is not reflected in the simultation plz comment.

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Altair Forum User

Hi Rajeev,

Please share the model file (_0000.rad),h3d file and time history (T01) file of the same run.

Altair Forum User

Dear George ,

Thanks for the reply. *h3d file is large i am send *.rad and *.T01 file.

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Altair Forum User

Hi Rajeev,

The global energy curves seems to be fine. The top and bottom face sheets are crushed easily in this scenario.Appropriately, the KE is also increased in that phase.

You can create an output block for all the parts and thereby you can monitor the internal energy developed for each part, and this will give a more clear picture.