Contact Enhancements
After two dedicated sessions on 3DExperience platform, we now begin with the updates on our traditional Abaqus solver updates. We have a lot more updates and as a result information to share this year compared to previous releases. You will see more blogs on updates and new features this year compared to previous years. Stay tuned.
Non-Circular Beams: Abaqus always had a library of standard cross section shapes to define beams with non-circular cross section. However, in contact modeling, the cross-section shape is circumscribed by a circle to detect contact. This has not been the best way to detect contact in beams. The realistic representation of contact for beams with non-circular section was introduced in Abaqus explicit in 2022xHF1 and it has been introduced in Abaqus standard in 2023xHF4.
Shell Thickening: The thickening of shells is uncommon, but it is possible in some applications under in plane compressive loads. Abaqus explicit can now simulate the thickening of shells. The shell thinning has been available in Abaqus explicit since years.
Domain Dependence Noise: The large element to element contact models exhibited noise and unstable behavior with domain decomposition with large number of domains. This problem was specific to Abaqus explicit that has been fixed in 2023xHF5 release.
Uniform Coupling: Apart from kinematic and distributed coupling, a new one has been introduced for the temperature and electric potential degrees of freedom. These couplings can reuse the reference node and surfaces of structural couplings. These have been developed to enhance the battery workflow.
Additional PPEN output: The fluid pressure penetration option of the distributed load keyword now supports nodal fluid penetration force (PFORCE) as the output. It has been introduced in 2023xHF3 in both standard and explicit. The critical contact pressure associated with change in the wetted status can now be defied with amplitude. 2023xHF3
ALE Enhancement: Its not true that explicit analysis cannot fail because of large deformation. Explicit can fail as well in case of element collapse. That is where ALE helps by using Eulerian approach near boundaries where large deformation occurs. In previous releases, ALE was limited to contact pairs. It is now available for general contact as well and gives much better domain decomposition performance compared to contact pair approach. 2023xHF3
Cohesive for beams: The beam-to-beam cohesive behavior has been introduced in the explicit and already exists in standard. In explicit the behavior is limited to circular beams at present. Contrary to the belief, the cohesive behavior as a surface property does not require complex material properties if damage is not included. Abaqus automatically computes a suitable cohesive stiffness from the *cohesive behavior keyword and no additional material inputs are required. 2023xHF3
Solid Electrolyte: The battery modeling workflows now support solid electrolyte using species concentration. It is indeed a contact enhancement as the interaction between electrodes and the electrolyte is modeling using a contact definition that uses a Butler-Volmer interface in this case. The species concentration is an additional degree of freedom. 2023xHF3
Abaqus Explicit Enhancements
Step Control: This is a feature to stop the explicit analysis or a given step of it based on critical solution state. It is also possible to refine the increment size around the critical state. It is ideally a sensor-based approach where a sensor threshold value is specified to stop the simulation or terminate the step.
Here sensor name is the name of the output variable on which the sensor is expected to act. It could be a history or field output.
EM Losses: User can now import high frequency losses from CST into Abaqus to perform a thermal analysis in Abaqus. As high frequency waves cannot penetrate a solid object, the losses are primarily applied on the surface as a heat flux.
Mapper performance: This feature relates to importing the results of an analysis as an input for subsequent analysis that is often done in case of sequential simulations such as thermal->structural. The mapping often took longer time and sometimes failed for very large models with millions of cloud points. The mapper has been updated for better performance. Two use cases are shown below.
Abaqus CAE Enhancements
Beam Offset: The offset of beam centroid from the section origin has been supported for section integration before analysis. Now the offset can be defined for the section integration during analysis.
Beam Profiles: The C-Channel and the HAT Channels have been added to the library for both the standard as well as the explicit.
Contact Mass Scaling: This feature applies local mass scaling at the contact locations so that critical time step is not compromised due to contact penalty stiffness. The UI is now supported in CAE. However, it’s a bit counter intuitive. While the element or global mass scaling is introduced through step module, the contact mass scaling is introduced through the interaction module.
LCP Contact: This contact is a linearized version of contact. It was introduced in general static step earlier to be used in situations where model has linear boundary conditions in combination with other sources of non-linearity. The LCP contact is now available in static perturbation step as well to account for small frictionless sliding that cannot be modeled with ties. It is applied through step module which means it is applied globally on all possible contact regions similar to general contact in general static step.
SPH Visualization: The SPH particles can now be rendered with edges display. However, apart from making appropriate changes in the “common display options” to include exterior edges, the user also needs to activate the display in the “ODB display options” menu to activate the feature.
General Contact Updates: Its no wonder that with time and new releases, the general contact is getting more powerful in Abaqus. SIMULIA discourages users to use contact pairs in the explicit and recommends avoiding contact pairs in standard as well. As a result, all the missing features of contact pairs are now showing up in general contact. The latest one is step dependent general contact in Standard. The use can now include and exclude in general contact at step level. Its also possible to visualize and manage general contact at step level using the interaction manager.
TOSCA Optimization: The optimization module of CAE has all the features for building TOSCA model. The “edit optimization process” window now supports DSLS SIM Unit licensing feature where user can select between tokens and credits to run a job.
Copy sets and surfaces: It has always been possible to create a copy of sets and surfaces at part level. The same feature is now available at assembly level. The sets and surfaces imported in the assembly module from part level can now be copied from the model tree. Copy from menu or from sets and surface manager is not supported yet.
Python Scripting: Python 2.7 has been deprecated in Abaqus 2024 and it now supports python 3. Scripts upgrade tool is available for the conversion. Abq2024 python -m abqpy2to3 <file names> or from CAE as plug-ins->abaqus->upgrade->scripts. Backward compatibility exists to support python 3 scripts in earlier releases of python.
Leave a Reply