Thickness Reduction of Shell Elements

[Nan Guofeng]

Dear all,
 
I'm now simulating tube crushing with Abaqus/Explicit. The tube is meshed with shell elements, and general contact is used for contact. As the mesh goes finer, the thickness of elements reduces and there's a warning message as follows:
 
In step 1, some facet thicknesses for general contact were reduced
            from the parent element or specified values due to a large
            thickness compared to facet dimensions.  The most significant
            thickness scaling factor was 0.39114 for a facet on parent element
            5772 of instance ETA_25-1.  An element set named
            "WarnElemGContThickReduce" has been created for use in
            ABAQUS/Viewer to locate the regions of reduced thickness.
 
I know that such thickness reduction is required by the contact simulation, but can anyone give some comments on to what extent such reduction will influence the final results? and is it possible to know the amount of thickness reduction for each element whose thickness has been reduced. (As the warning message only gives the most significant reduction value).
 
Many thanks and kindly regards,
 
Song J.


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[Bartosz Gradzik-1]

Hi,

There is no option to switch off contact reduction for all shell elements in
a model, but you can reduce number of elements for which Abaqus will made
reduction. To do it you need to use keyword:
*CONTACT CONTROLS ASSIGNMENT, CONTACT THICKNESS REDUCTION=SELF
or
*CONTACT CONTROLS ASSIGNMENT, CONTACT THICKNESS REDUCTION=NOPERIMSELF
For more information please take a look to documentation, chapter 30.3.6
CONTACT CONTROLS FOR GENERAL CONTACT IN Abaqus/Explicit, Control of contact
thickness reduction checks.

To plot contact thickness in general contact you can use field output
CTHICK.

Regards,
Bartosz

Nan Guofeng wrote:

Dear all,
 
I'm now simulating tube crushing with Abaqus/Explicit. The tube is meshed with shell elements, and general contact is used for contact. As the mesh goes finer, the thickness of elements reduces and there's a warning message as follows:
 
In step 1, some facet thicknesses for general contact were reduced
            from the parent element or specified values due to a large
            thickness compared to facet dimensions.  The most significant
            thickness scaling factor was 0.39114 for a facet on parent element
            5772 of instance ETA_25-1.  An element set named
            "WarnElemGContThickReduce" has been created for use in
            ABAQUS/Viewer to locate the regions of reduced thickness.
 
I know that such thickness reduction is required by the contact simulation, but can anyone give some comments on to what extent such reduction will influence the final results? and is it possible to know the amount of thickness reduction for each element whose thickness has been reduced. (As the warning message only gives the most significant reduction value).
 
Many thanks and kindly regards,
 
Song J.


      ___________________________________________________________
  好玩贺卡等你发，邮箱贺卡全新上线！
http://card.mail.cn.yahoo.com/

[Non-text portions of this message have been removed]