Edoardo90
Guest
good evening to all, I am Edward, new user in this forum, and I have a question to ask you about the software patran (version 2012, but this makes little difference).
I have a problem with checking overly distorted elements in Patran, explaining the problem.
Coming from the fem environment in ansys, I was accustomed to receiving warning messages from the software immediately after meshato a surface or a solid if excessively distorted elements were created, that is, with non-acceptable jacobiano (null or negative, singular matrix and therefore not invertible), thus being able to solve the a priori problem of numerical analysis, i.e. the launch of the calculation.
In Patran there are no these instant warning messages so, in these few weeks of learning on patran, I did check to "eye" mesh to verify that there were no elements or areas with too distorted elements, and therefore not accepted in the calculation.
the problem is that very elongated elements can be present not visible the first time to the eye. the point therefore is that it is necessary to wait to download the bdf, to launch the calculation in the nastra, and to wait for the famous message "fatal error" in which nastran says, rightly, not to be able to continue the calculation of matrix of rigidity or similar since he met elements with jacobiano not acceptable, and also indicates some ids of elements.
I noticed that in patran there is a verification tool, going on the "elements" button, action: verify, object: element and test (two possibilities): jacobian zero or ratio. the problem is that I have not understood how to use these options, more than anything I can not well understand the chart that patran displays after the application of jacobian zero.
Finally, I would like to know if in Patran the only way to verify the distortion of the a priori elements of numerical analysis is that and, if yes, how to use it correctly.
I thank you in advance and apologize for the length of the text.
Thanks again for the attention to the discussion I propose, I accept advice!
good weekend,
Edoardo
I have a problem with checking overly distorted elements in Patran, explaining the problem.
Coming from the fem environment in ansys, I was accustomed to receiving warning messages from the software immediately after meshato a surface or a solid if excessively distorted elements were created, that is, with non-acceptable jacobiano (null or negative, singular matrix and therefore not invertible), thus being able to solve the a priori problem of numerical analysis, i.e. the launch of the calculation.
In Patran there are no these instant warning messages so, in these few weeks of learning on patran, I did check to "eye" mesh to verify that there were no elements or areas with too distorted elements, and therefore not accepted in the calculation.
the problem is that very elongated elements can be present not visible the first time to the eye. the point therefore is that it is necessary to wait to download the bdf, to launch the calculation in the nastra, and to wait for the famous message "fatal error" in which nastran says, rightly, not to be able to continue the calculation of matrix of rigidity or similar since he met elements with jacobiano not acceptable, and also indicates some ids of elements.
I noticed that in patran there is a verification tool, going on the "elements" button, action: verify, object: element and test (two possibilities): jacobian zero or ratio. the problem is that I have not understood how to use these options, more than anything I can not well understand the chart that patran displays after the application of jacobian zero.
Finally, I would like to know if in Patran the only way to verify the distortion of the a priori elements of numerical analysis is that and, if yes, how to use it correctly.
I thank you in advance and apologize for the length of the text.
Thanks again for the attention to the discussion I propose, I accept advice!
good weekend,
Edoardo
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