willsen
Mechanical
- Sep 2, 2016
- 5
Hi,
I have been developing a constitutive model (implemented in VUMAT) which describes the deformation behaviour of fibrous glass tows that constitute a plain weave textile. This constitutive model is just a new extension of small elasticity in the hyperelastic framework. I am interested in understanding the compaction behaviour of such textile architecture. The attached picture (top) shows the uncompacted textile assembly. The textile is to be compacted between two analytically rigid plates (not shown in the picture). Explicit general contact is used to model the tow-tow interaction and plate-tow interaction. Following the compaction, I keep getting a weird compaction behaviour as can be referred to the same attached picture (bottom). Notice that for each interacting tow, only one is deforming severely and the other barely compacted. This is weird because for this initial run I specified the "transverse modulus" of each tow to be uniform throughout. I have checked every single possible reason: 1. Using fully integrated elements instead of reduced integration (to make sure that this is not an hour-glass effect). 2. Increase the total compaction time (to ensure that this is not a dynamic effect). But when I use a simple linear elastic material model from the ABAQUS library, the deformation behaviour is as expected. Before I am concluding that there is something wrong with my VUMAT, I am hoping that maybe anyone can point out any obvious mistake with the way I set up the simulation?
Thank you very much in advance.
Regards,
Willsen
I have been developing a constitutive model (implemented in VUMAT) which describes the deformation behaviour of fibrous glass tows that constitute a plain weave textile. This constitutive model is just a new extension of small elasticity in the hyperelastic framework. I am interested in understanding the compaction behaviour of such textile architecture. The attached picture (top) shows the uncompacted textile assembly. The textile is to be compacted between two analytically rigid plates (not shown in the picture). Explicit general contact is used to model the tow-tow interaction and plate-tow interaction. Following the compaction, I keep getting a weird compaction behaviour as can be referred to the same attached picture (bottom). Notice that for each interacting tow, only one is deforming severely and the other barely compacted. This is weird because for this initial run I specified the "transverse modulus" of each tow to be uniform throughout. I have checked every single possible reason: 1. Using fully integrated elements instead of reduced integration (to make sure that this is not an hour-glass effect). 2. Increase the total compaction time (to ensure that this is not a dynamic effect). But when I use a simple linear elastic material model from the ABAQUS library, the deformation behaviour is as expected. Before I am concluding that there is something wrong with my VUMAT, I am hoping that maybe anyone can point out any obvious mistake with the way I set up the simulation?
Thank you very much in advance.
Regards,
Willsen