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Error Message

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jonny17

Mechanical
Joined
Mar 6, 2012
Messages
33
Location
GB
Hi all,

I am currently doing an impact simulation of a human skull and a rigid planar shell surface i.e. 'floor'. However I am getting an error message part way through the job.

"The ratio of deformation speed to wave speed exceeds 1.0000 in at least one element. This usually indicates an error with the model definition. Additional diagnostic information may be found in the message file."

The model appears to be running fine in the visualization module prior to this message.
The skull has been defined as follows; density= 5.8668e-9 tonnes/mm^3; i.e. mass = 0.00366tonnes or 3.66kg; E=9200MPa poissons ratio = 0.22. The model has been given an initial velocity of -2200mm/s at a negligible distance from the surface and a gravity force of -9810mm/s^2. I have given the model a friction interaction penalty of 0.3 with a damping coefficient of 4.0.

Thanks
jon

 
I forgot to add that along with the friction and damping contact properties I have also given a normal linear contact stiffness of 471N/mm.

Please help!
 
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