luc46552
Mechanical
- Jun 13, 2019
- 13
Hello, I'm a bit new to Abaqus FEA, so please bear with me. I'm wondering if anyone has experience switching from an implicit model to an explicit model in the same simulation.
I'm working on a research project that requires several static, general steps and then a final dynamic step. The dynamic simulation involves a lot of rigid body motion and non linearity, but up until now I have been able to get it to work in dynamic implicit. Regardless, I'm finally running into convergence issues that can't be solved in implicit, and it would be more efficient to run an explicit simulation anyway.
From my understanding, it is possible to switch from an implicit to an explicit simulation as long as you create a new model and output the results of the first, implicit model as a .res file. You can then and use a predefined field to pick it up in the second, explicit model. However, I am running into some problems when I do this and there seems to be a lack of resources online to solve this particular issue.
Basically, I have a copy of the implicit simulation with only the initial step (material properties, BC's, interactions, etc... are all the same) and I created a predefined field linking the initial state of the explicit simulation to the final state of the implicit simulation. When I submit the explicit simulation, it does find the .odb file and begin running, but I get multiple errors of the following type:
in keyword *BOUNDARY, file "CobraWeaveExplicit.inp", line 113: Unknown part instance node set "Large Stick-1-lin-1-1"."Large Stick"
I have a linear pattern in the assembly that defines multiple instances of the same part (so I can use a .py file to make it any length). My best guess would be that the explicit analysis is not recognizing the node sets automatically generated by the linear patterns in the assembly. However, I wouldn't know why this would be the case, and I can't find any resources on how to fix it.
I'm working on a research project that requires several static, general steps and then a final dynamic step. The dynamic simulation involves a lot of rigid body motion and non linearity, but up until now I have been able to get it to work in dynamic implicit. Regardless, I'm finally running into convergence issues that can't be solved in implicit, and it would be more efficient to run an explicit simulation anyway.
From my understanding, it is possible to switch from an implicit to an explicit simulation as long as you create a new model and output the results of the first, implicit model as a .res file. You can then and use a predefined field to pick it up in the second, explicit model. However, I am running into some problems when I do this and there seems to be a lack of resources online to solve this particular issue.
Basically, I have a copy of the implicit simulation with only the initial step (material properties, BC's, interactions, etc... are all the same) and I created a predefined field linking the initial state of the explicit simulation to the final state of the implicit simulation. When I submit the explicit simulation, it does find the .odb file and begin running, but I get multiple errors of the following type:
in keyword *BOUNDARY, file "CobraWeaveExplicit.inp", line 113: Unknown part instance node set "Large Stick-1-lin-1-1"."Large Stick"
I have a linear pattern in the assembly that defines multiple instances of the same part (so I can use a .py file to make it any length). My best guess would be that the explicit analysis is not recognizing the node sets automatically generated by the linear patterns in the assembly. However, I wouldn't know why this would be the case, and I can't find any resources on how to fix it.