analyze multiple groups of elements simultaneously in patran-nastran

[MichMik]

Good evening,

I have opened this discussion to ask you if it is possible in Patran to analyze multiple groups of elements at the same time, that is, after sharing a model in several parts, each inserted in a different group, I would like to know if, at the time of analysis with nastran, it is possible to analyze some groups of elements together, as if they were a single structure inserted in a single group. If you choose between the possible options entire model then the nastran solutor would send all the model, instead I would like nastran to process only the groups chosen by me.
I would also like to see that groups with adjoining elements, that is, with common knots, were treated as a whole from a structural point of view, that is, I would like the solutor to treat them as if they were united along the common knots.
thanks for possible availability.

 

[Onda]

You have to make an equivalence between the knots, with a greater tolerance than the distance between them, in practice the knots must be coincident and by making an equivalence you join them, making the structure one.

 

[MichMik]

Good morning,

In practice I visualize all the groups I need on the display of patran and before starting to solve the structure with nastran I make the equivalence. the problem however arises when I open the screen analysis, if in object select group option select, when I click on select group to choose which groups of elements analyze, I realize that I can select only one at a time. I should like instead to be able to choose more than one and treat them as if the elements present in them belonged to a single group.
Thank you for the time you dedicate me.

 

[MichMik]

However I tried to bypass the problem, so I created an additional group where I inserted all the groups of elements that I wanted the solutor to process together, then in the analysis screen I selected this new group and analyzed it with the nastran. I would like to know if this is the only way to proceed or if you can select multiple groups to analyze, as if they were a whole, when you access the analysis screen.
Thanks again for the attention.

 

[Onda]

you can't select multiple groups, but you can make a group that contains them. groups are not autocad layers. each group may contain any entity. then you can perform boolean operations between groups, join them to separate them etc.

 

[MichMik]

I understand, so you can only analyze one group at a time, but you can always join in one group those that we are interested in analyzing together.
Thanks again for the help.