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Squeak and Rattle
Create and evaluate evaluation lines and optimize interfaces to eliminate squeak and rattle issues.
Post Processing
Launch and explore Squeak and Rattle Director post processing.
Optimization
Setup an optimization solver deck to get solution proposals.
Setup Systematic Optimization
Systematic method can be used to setup a 1D topology optimization to highlight and find the prominent locations to add or position fixation points.

Welcome
What's New
View new features for HyperMesh NVH 2025.1.
Get Started
Learn the basics and discover the workspace.
Tutorials
Discover NVH functionality with interactive tutorials.
Full Vehicle NVH
Access the Assemble, Analyze, NVH Tools, NVH Post, and Physics AI ribbons.
High Frequency NVH
High frequency NVH is an implementation of Statistical Energy Analysis (SEA), and is used to predict and analyze the vibration and acoustic response of complex dynamic systems.
Squeak and Rattle
Create and evaluate evaluation lines and optimize interfaces to eliminate squeak and rattle issues.
- Technical Concepts
  Technology and problem evaluation approaches used in SnRD.
- Launch Squeak and Rattle Director
- Model Build
  Convert rigid connections from a NVH model into flexible connections for squeak and rattle assessment.
- Pre-Processing
  Explore the SnRD Pre-Processing user interface.
- Post Processing
  Launch and explore Squeak and Rattle Director post processing.
  - Risk Assessment
    Use the SnR Risk Assessment Browser to load files and post process results.
  - Sensitivity Analysis
    Use a sensitivity analysis to study modal contribution.
  - Combined Loadings Analysis
    Use the Combined Loading tab to review and analyze the effects of Dynamic and Static loads on the gap and relative displacement.
  - Optimization
    Setup an optimization solver deck to get solution proposals.
    - Setup Systematic Optimization
      Systematic method can be used to setup a 1D topology optimization to highlight and find the prominent locations to add or position fixation points.
    - Setup Non Systematic Optimization
      The non systematic optimization method is used to setup a 2D free-size topology optimization to highlight the load paths and areas to reinforce.
    - Export Optimization Deck
      Export of optimization solver deck and perform Fourier Transformation.
  - DOE and Stochastics
    Use DOE and Stochastics to understand the parameter variation study.
  - Static Solidity
    Use the Static Solidity Post tool to generate all results of interest for static solidity loadcases.
  - Diagonal Distortion
    Calculate diagonal distortion across the closures and body openings.
  - Report
    Create a report for the risk assessment of the squeak and rattle analysis.
- Ziegler PEM Material Database
  Use of Altair Ziegler SnRD Material Database.

Setup Systematic Optimization

Systematic method can be used to setup a 1D topology optimization to highlight and find the prominent locations to add or position fixation points.

Setup Optimization Deck

From the SnRPost ribbon, select the Optimization tool.

Figure 2.

The SnR Optimization Browser opens.
Select a loadcase and the required E-Line.
Choose the Optimization Direction.
Click Load.
The model, post processing results, selected loadcase, and E-Line are loaded into the session. The following items display:
- .H3D file of MTRAN analysis, showing selected interface and all 2D Parts.
- Relative displacement graph for selected interface.
- Relative modal contribution bar chart.
- .H3D file of modal analysis.
Select the required frequency.
Select the Auto Fill check box.
The Min. (Hz) and Max. (Hz) value fields are automatically populated. If only one frequency is selected, Single Freq. (Hz) is automatically populated.