AVL EXCITE™ 2019 R1 - AST Product Releases
AVL EXCITE™ 2019 R1
The latest EXCITE™ version enhances usability, performance and accuracy of transmission, EHD bearing analysis and various other applications. New evaluation Apps and workflows, e.g. calculation of transfer functions, provide efficient and comprehensibly approaches to check the simulation model quality. Enhancements of the FE interfaces are further streamlining the data exchange with EXCITE™ and offer additional analysis capabilities.
All new capabilities of AVL EXCITE™ 2019 R1 are described in detail in the release notes. A summary is given in this release info.
Transmission Analysis (Conventional and Electrified Powertrains)
Ball Bearings – Influence of Centrifugal Forces
For high speed applications like turbocharger or e-motor analysis the roller bearing models with spherical rolling elements have been extended to consider the influence of centrifugal forces acting on the rolling elements. Thus, effects like change of contact angles, additional loading/unloading in the contact between rolling elements and the outer/inner raceways, change of axial pre-load can be considered.
Consideration of centrifugal forces on rolling elements
Spline Gear Joint – Multi-plane Approach
To account for tilting effects and angular misalignments arising in spline gear connections, a multi-plane approach has been added to the existing functionality of the spline gear joint. The extension supports multiple central nodes on shaft and hub and creates calculation planes for each node-pair. Stiffness and damping properties are automatically set for the individual planes considering an optional user defined stiffness distribution across the planes.
Planes and central nodes generated based on user specification
Gear Contact Pattern Plot – Additional Result Quantities
Additional local contact properties like pinion and gear radii of curvature of flanks, tangential velocity at flank contact points of pinion and gear and friction coefficient (either according to input or from EHL-calculation) can be exported and visualized using the Contact Pattern Plots. With the extended output of contact quantities also specific external post-processing can be applied to the simulation results, e.g. flash temperature evaluation for scuffing assessment.
Planetary Gearset Phasing Tool – Usability
Various enhancements have been made in the planetary gearset phasing tool to improve usability. These include the global reset of an angular offset for all Advanced Cylindrical Gear joints, automated evaluation of gear wheel filling area for visualization and the link of the unit system with the FEM preferences.
New Result Evaluation Apps and Workflows
Transfer Function Evaluation
For calculating transfer functions, the new COMPOSE™ workflow applies a white noise excitation (unit load) using the same mass, stiffness and damping matrices as for the transient dynamic simulation.
Among others, the transfer functions between excitation and evaluation positions are very helpful to check the quality of the model representation of complex structures (e.g. transmission housing with e-motor connected, stator of e-machines, …) by comparing them with measured transfer functions obtained by hammer or shaker excitation. The comparison shows how well the damping of the structure is defined and if the response peaks are at comparable frequencies.
Example – Transfer function between combustion chamber and engine mount
TVD Temperature Calculation
This COMPOSE™ App calculates the temperature of a torsional vibration damper (TVD) for an EXCITE™ Designer model considering temperature dependent stiffness and damping properties.
Dissipated heat and mean TVD temperature over engine speed
Elasto-hydrodynamic Contact Models
Time/Angle Dependent Temperature Boundary Conditions
The temperature of polygon boundary conditions and the surface temperature profiles of both connected bodies of the elasto-hydrodynamic contacts for radial/axial slider bearings and the piston (EHD2, AXHD and EPIL) can now optionally be defined time or angle dependent. Same as for the time/angle dependent pressure boundary condition, linear or cubic interpolation as well as periodic, constant or linear extrapolation can be applied.
Enhanced Calculation of Friction Moment
The improved calculation of friction moments is particularly important for applications with floating bodies, e.g. floating piston pins, to calculate more accurately the movement and rotation of the floating body due to the friction moment.
Improved Performance for Floating Bushing Applications
The convergence (simulation time and stability) for models containing more than one EHD joint coupled to the same body with nearly the same center (e.g. floating bushing bearings) has been improved considerably.
Generic Thermal Load Interface for EHD Bearing Analysis
The COMPOSE™ workflow Thermal Load allows to couple EXCITE™ Power Unit with third party FE or CFD codes for an offline calculation of structural temperatures and thermal deviations of EHD bearings.
The Workflow consists of two Apps: the Thermal Load Generator App exports EXCITE™ heat flux and heat transfer coefficient data as input for the external thermal analysis, the Thermal Profile Generator App generates temperature profiles and radial thermal deviations as input for EXCITE™ based on the FE or CFD thermal analysis results. In both cases easy adoptable Excel CSV files are used for the data exchange.
Since version MSC Nastran 2018.2 a direct export and import interface of EXCITE™ Data is supported. In EXCITE™ 2019 R1 the appropriate FE Analysis Tasks – Condensation and Dynamic Response Analysis – have been updated accordingly.
The streamlined workflow between both tools improves performance, reliability and safety. Examples for the improved workflow are: no DMAP’s are required, less disk space is used (no .OUT2/.OUT4 files), Nastran SOL 400 is supported as well as the use of external superelement databases for a data recovery of EXCITE™ results.
Workflow Nastran SOL 400 Condensation > AVL EXCITE™ > Nastran SOL 400 Data Recovery
Abaqus 2018 is fully supported by EXCITE™ 2019 R1 including the new capability to recover results within a substructure in Abaqus with the Abaqus substructure recover utility using the modal recovery matrices. The recovery can be performed for dynamic time-domain or frequency-domain results obtained from EXCITE™ Power Unit.
The FE analysis task - Linear Static Stress Analysis - up to now a mix of generated ANSYS input files and APDL macro functionality (e.g. for applying EHD pressure as boundary condition), has been cleaned up and now a proper ANSYS input file is written containing all loads. Therefore, the use of APDL macros will be discontinued.
EXCITE™ Power Unit
- Valve Train and EXCITE™ Valve: various usability improvements (optional user defined connection nodes for joints, node sorting for link locations, …)
- NVH post-processing workflow: stacked bar charts, 1/12 octave and bark bands, …
- EXB-Explorer: surface visualization of stored FE meshes, calculation of eigenfrequencies and visualization of mode shapes
- Micro-Contact analysis tool: enhanced accuracy of flow factor calculation, extended data limit for input files
- Mount joint EMO1: model parameter identification extended to 2kHz
- Optional GPU usage for specific kernel operation on Linux
- Mount Layout Tool: import of transient load data from EXCITE™ Power Unit results or load data; animation of forced response (dynamic analysis)
- 3D ring post-processing: additional evaluation of average LOC at TS & ATS
EXCITE™ Timing Drive
- User defined result script statistics extended by peak-to-peak and magnitude results
- Improved definition of frequency dependent boundary conditions