AVL EXCITE™ 2019 R2 - AST Product Releases R2
Streamline your structural dynamics simulations
AVL EXCITE™ 2019 R2
The latest version of our leading modelling solution
The latest version of AVL EXCITE™, our innovative rigid and flexible multi-body dynamics software solution for powertrain analysis has just been released. AVL EXCITE 2019 R2 improves the usability and functionality of a variety of pre and post-processing tasks and workflows.
New model capabilities extend the application scope for gear drive and transmission analysis and the analysis and design of piston rings. With the option of parallel simulation runs, throughput time for sound radiation calculations can also be significantly reduced.
Transmission Analysis (For ICE an Electrified Powertrains)
EXCITE 2019 R2 now allows for the consideration of translation deflections of the raceways in roller bearings. The contact model between rolling elements and inner and outer bearing raceways has been extended, taking into account geometric deviations from the ideal circular shape. An optional distribute node coupling of the rolling element and the inner and outer raceways can also take into account translational deflections of the races.
This new functionality provides a more accurate picture of bearing loads upon the housing and shafts, which is especially beneficial for acoustic applications. This is due to the distribution of the loads throughout the circumferential nodes and the consideration of deformations of the races. These deformations are caused by bearing loads and non-uniform housing stiffness.
All physical rolling element bearing models are supported, except for the map-based models.
Example: outer race node "5" moved 100μm outside the ideal circular shape
Advanced Cylindrical Gear Joint
New types of micro-geometry for advanced cylindrical gear joint modeling have been added to this latest release of EXCITE. The linear and circular tip and end relief micro-geometry modification option benefits from the addition of parabolic tip/root and end relief modification.
These specific micro-geometry types can be easily defined in the gear contact model. This enables the evaluation of their effects upon tooth contact behavior and the overall dynamic behavior of any gear-driven system.
In addition to these new micro-geometry types, a new tooth profile correction option has also been added. The bias/twist correction is used to compensate any non-preventable bias errors that might have been introduced during the grinding process of helical gears. It helps to avoid the negative effect on tooth contact behavior and any deterioration of the gear’s load-carrying capacity.
New tooth profile modification/corrections: parabolic tip/root and end relieve, bias/twist correction
Elasto-Hydrodyamic Contact Models
Wear Analysis Workflow
This new release of EXCITE extends the COMPOSE™-based wear analysis workflow with the addition of sequential case execution. This allows all cases selected in the operating condition table to run in a defined sequential order. In each simulation iteration, the wear depth that is calculated is carried through into the next iteration and the final result of a case is input for the following case.
The maximum wear-depth per simulation iteration can be defined in a number of ways:
- Automatically calculated per iteration to not exceed composite summit roughness
- Wear depth scaled by accumulation time
- User defined, enabling the balance between overall simulation duration and result quality
The latest release also provides new wear statistic results relating to maximum contact pressure and wear volume. Furthermore, the wear analysis workflow can be easily adjusted to simulate the sequence of operating conditions on an engine or component testbed.
Wear analysis – sequential case execution
Axial Thrust Bearing
This new version provides new results for the elasto-hydrodynamic thrust bearing joint for both contact options, lubricated and dry contact. 2D shear results can be separated in the joint’s directional components, based on evaluation of non-rotational velocity components in axial/radial directions on the contact plane.
The asperity and hydrodynamic contact stresses in axial/radial directions can now be calculated, in addition to the previously provided circumferential stresses. All thermal load and wear stresses are now based on the total velocity in the contact plane.
This new functionality supports a wide range of applications. This includes calculating the friction and wear of valve seats applying a conical shaped axial thrust bearing joint for the valve – valve seat contact.
Post-Processing and Workflows
Operational Deflection Shapes
The Operational Deflection Shapes COMPOSE workflow sees various enhancements in this new release. This includes new reader apps, one for EXCITE and a UFF file reader for measurement data. Further new capabilities for result evaluation and visualization include:
- Order steps can be added to visualization steps
- Separate scaling factors for relative displacements, global translation and global rotation
- Traces between deformed and undeformed wireframe
- Cycle type selection: quarter/half/full selection of cases for a defined list of step animations
- Consideration of phase shift at animation; saving and loading of animation data
- Video file generation for all selected cases and, for example, the ordering of steps as batch jobs
Frequency step animation with undeformed wireframe and trace
New COMPOSE App for Internal Data Recovery
The new COMPOSE App uses a full or partial recovery matrix to transform EXCITE results from the condensed FE model to the original uncondensed model. The recovery matrix must be requested and stored in the EXB file prior to recovery.
This supports transient and harmonic recovery of all three motion quantities. For the transient recovery, frequency filtering such as low-pass, high-pass and band-pass filters can be applied.
Internal Data Recovery App in COMPOSE™
Pre-Processing and FE Interfaces
EXP Explorer Extensions
The EXP Explorer now incorporates the functionalities of two former utilities. “Check (Radial) Stiffness” enables the radial stiffness of a bearing housing to be checked by defining the bore center and surface of the bearing. With user-defined single point constraint and force of moment any stiffness can be checked.
The second one, “Prepare Section Force”, supports the addition of node connections and element stiffness matrices for shaft and crankshaft components. This is for the evaluation of section forces and moments of shafts and all types of crank webs after a transient analysis. For the result evaluation of section forces and moments, all required data is now read from the EXB file. This includes data such as node connections, element stiffness matrices, the location of web points and user-defined evaluation points. This means that re-runs of the model creation task are no longer necessary.
EXP Explorer integrated Check of Radial Stiffness
FE Interfaces – Support of PERMAS
The EXCITE FE interface solution now supports the FE Solver, PERMAS (version 17). Generating control and input files for PERMAS, this version supports the following FE analysis tasks:
- Natural frequency analysis
- Dynamic response analysis
PERMAS FE analysis can be launched directly as a solver task via the JMS job submission.
New FE Solver option: PERMAS
Three Piece Oil Control Ring*)
In addition to the single and two-piece oil control ring models, which are based on the 3D piston ring, comes a new three-piece oil control ring model. This type of oil ring has two separate rails connected by an expander/spacer. The expander/spacer characteristics can be calculated by EXCITE Piston&Rings using predefined relative displacements between the rails, or by table input based on measurements or FE pre-calculations.
All the results provided by the 3D ring module are available separately for both rails of the three-piece oil ring. This new model supports important investigations that promote design optimization. This includes topics such as the influence of expander/spacer characteristics on the dynamics and motion of the two rails. Another topic is the influence of rail profiles and their independent twist on left oil film thickness, oil consumption, gas flow, friction and wear.
Example: distribution of top and bottom ring rail total contact pressure
*) not part of main release 2019 R2, will follow with one of the 2019 R2 maintenance releases
A new feature within our latest release enables the parallel simulation of frequency ranges. This allows to split the sound radiation calculation for one operation condition two to eight parallel ranges without any additional licenses. The result is a shortening of the overall run time by up to five or six times.
The simulation run is separated into the following phases:
- Model preparation
- Simulation of frequency ranges from 1 up to 8
- Post processing
To achieve similar duration for each range, the frequency ranges are split automatically. Finally, the results of all frequencies are merged to results as obtained by a non-parallel run.
Job overview of an EXCITE™ Acoustics parallel simulation run
Further Enhancements in EXCITE 2019 R2
EXCITE Power Unit
• Modal Analysis – improved usability of mode browser
• Utility “Modal Data Recovery” – optional selection of mode shapes from previous Modal Analysis for MPF/MCF evaluation
• ROTX joint – more accurate evaluation of damping part in 3D rotations
• Piston-Liner Contact (EPIL) – different surface contact parameters along liner height
• Micro-contact analysis – support for import of Brucker Wyko V.64 file types
• Shaft Modeler – non-structural mass for single-mass disk, ring of TVD, and shaft-in-shaft elements with “slide” option
• MSC Nastran™ – response analysis improved and version 2017.1 added
• ANSYS ® – support of rigid and average motion spider elements for natural frequency analysis and condensation
• Main Bearing and Web Load – viscous and material damping for slider and ball bearings
• Rotor dynamics simulation in frequency domain using Main Bearing and Web Load task
• Option to ignore structural nodes with no element connection for acoustic mesh generation