CDH AG

Vehicle comfort

Various physical effects cause vibrations in the vehicle, which can significantly impair driving comfort. The engine-transmission unit excites the vehicle structure. Vibrations are also transmitted to the occupants through the tires, suspension, and steering system. Additionally, structural vibrations are caused by airflow at higher speeds. Overall, this results in a large number of load cases that need to be analyzed.

We support our customers at various levels of complexity. We use simulation results to derive targeted measures for optimizing parts and components, ensuring the desired results are reliably achieved across the entire vehicle.

Vibration comfort

We use the following CAE methods to analyze and optimize components in various disciplines:

BODY IN WHITE AND TRIMMED BODY
  • Static linear calculations of the body shell to evaluate stiffness, global torsion and bending, local connection points, and stress and strain distribution
  • Body structure optimization (sheet metal thicknesses and shaping)
  • Radiated energy analyses
  • Sheet metal field participation analyses
  • Acoustic modal analysis
  • Numerical acoustic optimization
  • Robustness studies to evaluate influences from production and material deviations
  • Correlation of test and CAE simulation results
SUSPENSION SYSTEM
  • Modeling
  • Analyses of driving noise, steering system and wheel imbalance
  • Analyses of steering column vibration
  • Evaluation of body mounts
  • Tuning of suspension system
FULL VEHICLE
  • Modeling of the full vehicle system
  • Low- and high-frequency NVH analysis (engine noise, howling, road noise, etc.)
  • Influence and coordination of individual components in the overall system to optimize overall vehicle comfort
  • Time-domain analysis
  • Hybrid modeling (consideration of measurement results in the simulation model)
  • Definition of criteria for achieving targets in overall vehicle acoustics

Vehicle Acoustics

The aim of developing interior vehicle acoustics is to reduce sound pressure at ear level.

For the simulation, the passenger compartment cavity with all its mechanical properties must be represented in the calculation model and coupled to the vehicle structure.

We carry out the following analyses:

ACOUSTIC ANALYSES OF AIRBORNE NOISE
  • Analyses of the natural modes and eigenvalues of the interior cavity
  • Airborne sound sensitivities for frequency tuning of structural resonances
SENSITIVITY ANALYSES
  • Determination of the sensitivities of the parameters of the individual components in the frequency and time domains
  • Investigating how target variables of various properties change when component parameters are altered
  • Presenting the results as a color map to visually demonstrate the influence of the parameters of the components under investigation on the individual target variables
ENERGY ANALYSES
  • Acoustic radiation behavior of the structure
  • Energy Evaluations
  • Virtual transfer path analysis with the CAE tool CDH/TPA
  • Panel Participation Factor (PPF)
  • Grid Point Panel Participation Factor (GPPF)
TRANSIENT ANALYSES
  • Performing transient analyses in the time domain to analyze non-steady states of FE models. This allows time-, velocity-, and displacement-dependent nonlinear elements to be taken into account, as well as any time-dependent excitations.
STOCHASTIC ANALYSES
  • Variation studies to analyze the influence of production- and/or quality-related deviations on the NVH performance of the entire vehicle
  • Identification of NVH-sensitive components and material parameters
  • Cost/benefit assessments

Have we sparked your interest? We’d love to hear from you!

Contact Person: Dr. René Visser
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