1. OptiStruct for PT NVH

2. Copyright © 2015 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Full Vehicle NVH
Powertrain NVH
Body/Chassis NVH
Squeak & RattleWind Noise
Radiated Noise
Ride NVH
Brake NVH
OptiStruct solution for NVH
Full Vehicle NVH
Powertrain NVH
Body/Chassis NVH
Squeak & RattleWind Noise
Radiated Noise
Ride NVH
Brake NVH

3. Copyright © 2015 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
A comprehensive set of NVH solutions for upfront problem solving
• Full frequency, multi-physics NVH simulation capabilities
• Superior user experience in a highly integrated, automated framework
• Population performance based assessment, instead of single sample
• Optimization based design, instead of experience based design
OptiStruct for Powertrain NVH

4. Copyright © 2015 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
• A comprehensive high-performance FE-solver
• NVH Solutions
• Normal modes
• Preloaded normal modes
• Complex eigenvalue
• Frequency response
• Random Response
• Transient Analysis
• Acoustic Analysis
• Rotor Dynamics
• Solutions are “ready for optimization”
• Interfaces to AMSES and FastFRS
OptiStruct for Powertrain NVH

5. Copyright © 2015 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
• OptiStruct AMSES fast eigenvalue solver
• Calculate thousands of modes for millions of dof’s
• Handles unconnected structures
• Can be used with enforced motion (SPCD)
• OptiStruct FASTFR frequency response
solver
• Include thousands of modes with viscous and/or
structural damping
• Works with frequency dependent materials
• PARAM,FASTFR,(AUTO/ON/OFF)
• No additional cost for AMSES or FASTFR
OptiStruct for Powertrain NVH
0 20000 40000 60000 80000
AMSESLanczos
elapsed time (s)
AMSES VS Lanczos for Modal FRF solution
Eigen
Solution
Structral
Damping
Other

6. Copyright © 2015 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Total Sound Power
• The total sound power is the rate of change of sound energy with time in the domain
of reference
• The total sound power due to all the source grids can be calculated at a microphone
location for each frequency as follows

7. Copyright © 2015 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Sound Pressure
• Radiated Sound Output can be requested for grid points on the structural surface and
in the exterior acoustic field. Grid points are used to represent microphones to record
the radiated sound, sound power, and sound intensity.

8. Copyright © 2015 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Sound Intensity
• The total complex intensity vector is the sound power per unit area. The sound
intensity can be defined as a product of sound pressure and the particle velocity
vector
• For multiple source grids, the total sound intensity at a microphone location for each
frequency is given as follows

9. Copyright © 2015 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Equivalent Radiated Power
• Computation of the equivalent radiated power (ERP) is a simplified method to gain
information about maximum dynamic radiation of panels for excitations in frequency
response analysis.
• The ERP output of a panel is calculated as half the normal velocity squared of each grid
multiplied by the associated area of each grid on the panel.

10. Copyright © 2015 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Noise and Vibrations
• Frequency Dependant Materials
• Direct and modal FRF
• MATFx data
• Rotor Dynamics Analysis
• Modal frequency response and
complex eigenvalue analyses
• Synchronous and asynchronous
analyses
• Output data generation for the
Campbell diagram (critical speeds)
• Poro-elastic (BIOT) Materials
• MATPE data

11. Copyright © 2015 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
• Fast and accurate generation of AVL/EXCITE input data
• Condensed matrices
• FE model information
• Grid Displacement and Stress
• Directly coded in OptiStruct:
• No DMAP, scripts, or macros required
• AVL/EXCITE GUI for easy problem setup
• Post AVL/EXCITE analysis to recover
• Transient or frequency response stress and strain
• Displacements, Velocities, and Accelerations in seconds
• AMSES can be use for large problems
OptiStruct Interface to AVL/EXCITE

12. Copyright © 2015 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Post processing
.fem or .bdf
Model data/ matrices in ASCII or
binary format (.OUT2, .OUT4, …)
.exb
.INP4
.h3d or op2
Flexbody
.h3d
Model building/ conversion
MBD analysis
Stress and Strain
Recovery
Flexible Body Generation
.exb Generation
HyperMesh
Simlab
OptiStruct
AVL/EXCITE
AVL/EXCITE
OptiStruct
Process scheme – OptiStruct AVL/EXCITE Coupling

13. Copyright © 2015 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Optimization

14. Copyright © 2015 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
• ERP available as an internal response in OptiStruct
• Can also be applied to frequency sub-ranges
• Topology optimization successfully applied to identify internal rib
structure using ERP responses
• Optimized design proposal shows a significant improvement in the ERP
responses
Summary

15. Copyright © 2015 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Postprocessing

16. Copyright © 2015 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
The goal of the Equivalent Radiated Sound Utility is to post process results of
exterior structure-borne radiated sound
- ERP  H3D and PCH
- Radiated Sound (Power / Pressure)  H3D
Equivalent Radiated Sound Utility

17. Copyright © 2015 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
 Order analysis is a technique for analyzing noise and vibration signals in rotating or reciprocating
machinery. Examples include aircraft and automotive engines, compressors, turbines, and pumps.
 Order analysis is an easy way to separate structural phenomena (resonances, fixed frequencies)
from the rotational ones (variable frequencies). When presented in a frequency vs. rpm plot, you can
see the resonances as parallel lines to the rpm axis and rotating frequencies as lines increasing or
decreasing with speed (rpm).
Engine Order Analysis

18. Copyright © 2015 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Analyze
• Worst case scenario
• Critical components and locations
exceeding the allowed thresholds
• Effects of the latest design change
Automated Reporting Solution
Communicate
• Share findings frequently
• Right level of information
• Consistent appearance
Challenge
Large amount of data/results
Laborious repetitive tasks

19. Copyright © 2015 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Set-up
0.5 h
Load Template, apply
contour and adjust legend
per component
Refine/match ID’s and
part/component names
Verify model definition, e.g.
material, properties
Automated Reporting Solution
Assessment
3.5 h
Hotspot Finder or Measure
Panel: Mark critical result
locations
Adjust to best view, create
and save screenshot
Review each component
and identify critical
components
Report
2 h
Import all screenshots into
PPT master
Create Overview Table
Rearrange/format
slides/layout

20. Copyright © 2015 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
THANK YOU