Surface constacts

[JorgePF1]

Hi, I am importing a texgen dry fibre geometry into Abaqus for analysis. The upper and lower contact surfaces seems to have been created as sown in the .inp file however, the contacts are not shown in Abaqus interaction properties section. What could be the reason? Thanks AqWeaveGeo2.zip

[louisepb]

TexGen creates surface definitions for the upper and lower surfaces of the yarns which are then used in the contact definitions. For some reason the surface definitions haven't been created in your file. In order for TexGen to create surfaces you must have repeats specified for the yarns and the domain must represent a whole number of repeats. If these conditions aren't met then the surfaces won't be generated. I would check these first.

[JorgePF1]

Hello, Thank you for your reply. It is not clear what you mean by repeats. I normally follow the weave wizard to create the geometry and this does not ask for number of repeats. I am going to attempt to attach the files. I hope you will receive them. Create geometry_vr1.pdf, Contact issues.pdf and AqWeaveGeo2.inp in zip file. AqWeaveGeo2.zip

Contact issues.pdf Create geometry_vr1.pdf

[louisepb]

Hi, It seems that the issue is caused by the fact that you've chosen the regenerate mesh option with adjusting the mesh. I'm not sure at the moment why this would cause an issue but there's no point in choosing this option if the mesh hasn't been adjusted so I'll change the dialog so that it's greyed if adjust isn't chosen. In the case of your textile there is no point in selecting either of these options as there are no intersections anyway. If you just generate the dry fibre file without the regenerate mesh option then it creates the surfaces. If you render the paths and nodes on your model you will see that a small section is created and then repeat vectors are specified for each yarn. The domain specifies how large a section of the repeating yarns are selected. You can find out more by looking at one of the tutorials.

[JorgePF1]

Hi, I followed your advice as suggested. I generated the dry fibre file with regenerate mesh off 'WeaveGeo3.inp'. I noticed the interactions were generated. I switch off the 9 Disp-BC and set the analysis to solve. After 8hrs there was no solution. I decided to activate these 9x Disp-BC and the analysis did not run. I attached a file 'Contact issues_vr1.pdf' summarising the steps. Why is the analysis not converging? Is it related with these boundary conditions? Contact issues_vr1.pdf WeaveGeo3.zip

[louisepb]

Hi, are you running the simulation from the command line? You can't run this from CAE as it cannot deal with boundary conditions with multiple node sets. The constrained nodes are to prevent rigid body motion.

[JorgePF1]

Hello, I am opening the .inp file using Abaqus CAE 2020. How do you suggest to import the geometry and analysis setup?

[louisepb]

Hi, if you run the file from the command line then you will be able to import the odb file using CAE and view the geometry. If you want to retain the setup with boundary conditions with multiple node sets then you will need to edit the inp file, otherwise you could just import the geometry (nodes and elements) and set up the analysis yourself. I'm afraid that I'm not an expert Abaqus user - it would probably be more helpful to you if you could find someone in your institution who could advise on how to set up your analysis for your specific requirements

[JorgePF1]

Hello, No worries. I think I will set the analysis manually. I have one last question. Texgen generates the .inp file with the dynamic explicit set. I am wondering why is dynamic set as default. Also I noticed that top and bottom contact surfaces are not imported to Abaqus if I comment out the explicit dynamic commands. Why is this? However, when I run the analysis for both Static and Dynamic explicit the profile is somewhat similar. See attached (dynamic incomplete). Many thanks Static & Dynamic explicit.pdf