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NVH, Fatigue, and Frequency Domain Analysis with Ansys LS-DYNA

Course Overview

Traditionally LS-DYNA is well known as an advanced transient nonlinear finite element software. However, during the extended application of LS-DYNA in automotive and other industries, many users requested frequency domain analysis capabilities and fatigue analysis capabilities in LS-DYNA. These capabilities are essential for performing vehicle NVH (noise, vibration, and harshness) analysis and durability analysis. To answer the requests of the users, a series of frequency domain analysis features and fatigue analysis features were implemented to LS-DYNA.

This class provides you with a comprehensive introduction for the features for frequency domain vibration, acoustic and fatigue analysis in LS-DYNA. Time domain fatigue analysis is also included to make the fatigue analysis module complete. Introduction of some advanced capabilities in this area, such as brake squeal analysis based on rotor dynamics, NVH analysis based on IGA technology and SEA (Statistical Energy Analysis), is also included. This class also gives a detailed look at the application of these features in vehicle NVH and durability analysis. During the class, workshop examples are provided to help understand the corresponding keywords and the workflow for solving the problems.


  • You should have ba­sic knowl­edge of LS-DY­NA.

Teaching Method

Lectures and computer practical sessions to validate acquired knowledge.

Learning Outcome

Following completion of this course, you will be able to:

  • Understand of the frequency domain analysis and fatigue analysis keywords in LS-DYNA
  • Understand the vibro-acoustic and vibro-fatigue analysis workflow
  • Understanding the necessary linearization of the nonlinear model for NVH analysis
  • Know the pre and post-processing for the frequency domain analysis and the fatigue analysis


Available Dates

Currently, no training dates available

Learning Options

Training materials for this course are available with an Ansys Learning Hub Subscription. If there is no active public schedule available, private training can be arranged. Please contact us.


This is a 2-day classroom, lecture only training. For virtual training, this course is covered over 4 x 2-hour sessions lectures only.

Virtual Classroom Session 1 

  • Introduction
  • Module 1 – Introduction
  • Module 2 – Theory basis
  • Module 3 – Eigenvalue analysis

Virtual Classroom Session 2

  • Vibration
  • Module 4 – Frequency response functions
  • Module 5 – Steady state dynamics
  • Module 6 – Random vibration
  • Module 7 – Random vibration fatigue

Virtual Classroom Session 3

  • Acoustics
  • Module 8 – BEM acoustics
  • Module 9 – FEM acoustics

Virtual Classroom Session 4

  • Response spectrum, fatigue.
  • Module 10 – Response spectrum analysis
  • Module 11 – Time domain fatigue analysis
  • Module 12 – Advanced topics


  • NVH Theory and lab testing technology
  • Overview of LS-DYNA frequency domain features and applications
  • Frequency domain analysis vs. Time domain analysis
  • Fourier transform


  • Modal superposition method
  • Damping (viscous damping, structural damping)
  • Nodal force / Resultant force FRF


  • Large mass method
  • ERP (Equivalent Radiated Power)
  • Mode expansion with LS-PrePost
  • Mode contribution fraction plot
  • Direct SSD

Random vibration with PSD loading

  • Correlated and uncorrelated multiple excitations
  • Acoustic wave loads
  • Pre-stress condition
  • Multiple, different type loads


  • BEM, FEM
  • Vibro-acoustics
  • Incident waves
  • Acoustic panel / element contribution analysis
  • ATV and MATV
  • Frequency weighted SPL (dB)
  • Radiated sound power, radiation efficiency
  • Acoustic eigenvalue analysis

Response spectrum analysis

  • Input earthquake spectrum
  • Modal combination methods (SRSS, CQC, etc.)
  • Multi input spectra
  • DDAM


  • Fatigue theories
  • Fatigue analysis in harmonic / random vibration environment
  • Miner’s rule
  • Dirlik Method
  • Time domain fatigue (based on stress / strain)
  • Multiaxial fatigue
  • Mean stress correction
  • Fatigue load steps
  • Simulation of fatigue damage development
  • Fatigue failure and coupled mechanical-fatigue analysis

Advanced topics

  • SEA (Statistical Energy Analysis)
  • Brake Squeal Analysis
  • NVH analysis based on IGA
  • Linearization techniques

Auto NVH examples

  • FRF on BIW
  • Noise Transfer Functions (NTF)
  • Vehicle interior noise
  • Muffler Transmission Loss Analysis


  • Hands-on exercise
  • Post-processing of binary and ASCII databases (d3ssd, d3acs, d3ftg, nodout_ssd, elout_ssd, etc.)