NVH Director 2020 Release Notes
Highlights
- Spindle Loads
- Subrange and Overflow
- Frequency Response Assurance Criterion (FRAC)
- PreTest and Driving Point Residue (DPR)
- Engine Mounts Optimization
New Features
- Spindle Loads
- New feature for prediction of spindle loads integrated into the Analysis Manager. Spindle forces are calculated from experimentally measured operational spindle accelerations data and spindle structure FRF characteristics from the finite element vehicle model using inverse frequency response function (IFRF) method. These spindle forces are converted to principle vectors or random loads to be applied as forcing functions to the finite element vehicle model. This method is an alternative loadcase for Road NVH in absence of tire patch points excitations and reliable tire models.
- Subrange and Overflow
- New Subrange and Overflow features in the module ID management. Subrange allows flexibility in reserving IDs for SPOINTs, tagpoints and plotels anywhere within a module ID range. Overflow allows IDs for FE entities to overflow the assigned module ID range but still validate the module for reduced model (CMS-SE and CDS-SE) creation and use it in residual runs from the Analysis Manager.
- PreTest and Driving Point Residues
- New feature for prediction and optimization of the sensor locations (accelerometers) for measurements and directions along with test excitation point location, a very important step in the experimental modal analysis process directly affecting the accuracy of test results. There is a new option in the Model Correlation utility that has options to select the grids or import from the template .csv file for pre-test and driving point residue (DPR) calculations. The selected grids can be exported in CSV and UNV files.
- Frequency Response Assurance Criterion (FRAC)
- New feature for comparing two frequency response functions (FRFs) representing the same input-output relationship. This is used for comparing the strength of correlation between CAE and test FRFs. There is a new option in the Model Correlation utility that has options to select the FRF result files and calculate FRAC.
- Powertrain Mounts Optimization
- New feature for predicting powertrain rigid body modes frequencies and kinetic energy distribution which plays a critical role in optimizing the mount stiffness and layout configuration by decoupling powertrain rigid body modes and reduce vibration transmission. Powertrain mounting systems control the overall motion of the powertrain and maintains the position of the powertrain in the vehicle as it is subjected to inertia and torque reaction loads.
Enhancements
- Advanced Connections
- ID Forcing
- NVHD ID Manager
- GUI redesign of NVHD ID Manager for easy view and understanding of the module ID content. The ID range status shows the outliers possible to be tolerated and what has to be renumbered.
- Resvec for Viscous damping elements
- Enhancement in the Analysis Manager in identifying modules and connections with viscous damping elements, create a set of them and write RESVEC card for it in the solver deck on creating a job or export of solver deck.
- Prepare Module
- Enhancement in preparing representation FE files with sub includes. This allows SPOINTs validation for the module representation file with sub includes and creates reduced models.
- NVH Preferences
- Option to specify request for element force output.
- Tire Patch Points Manager
- Enhancement in tire patch points manager to handle tires in DMIG format.
- DMIG Representation
- Enhancement to support additional matrix types M2PP and B2PP for the NVH-OptiStruct user profile.
- Multiple Sample Analysis
- Enhancement in multiple sample analysis set-up in the Analysis Manager to show the information on number of modal and connection parameters getting randomized.
- Loads MSA
- Implementation of the normal distribution for imbalance distribution in loads randomization for Wheel and Tire Imbalance.
Resolved Issues
- Issue related to performance in MAC calculation due to memory management.
- Issue in performance of reading DSA result files.
- Issue in randomization of damping parameters for modal models.
- Issue in Plotel display options in switching between visualization.
- Issue in modal animation of transformed models in the Model Correlation utility.