OptiStruct is a proven, modern structural solver with comprehensive, accurate and scalable solutions for linear and nonlinear
analyses across statics and dynamics, vibrations, acoustics, fatigue, heat transfer, and multiphysics disciplines.

The OptiStruct Example Guide is a collection of solved examples for various solution sequences and optimization types and provides
you with examples of the real-world applications and capabilities of OptiStruct.

Demonstrate a Transfer Path Analysis (TPA) on a simplified vehicle model using OptiStruct. TPA is used to calculate and rank the noise or vibration contributions for a given Response Point, through the different
structural transmission paths in a system.

Demonstrates how to identify sensitive design parameters within a full vehicle NVH model, both as a way to understand
the dynamics of the system and what design changes can be made to improve a vehicle response, using OptiStruct and NVH post-processing in HyperView.

Demonstrate Infinite Elements, which is effectively modeled to measure the sound pressure of the 2.1 Home Theater
System in OptiStruct with effective modeling practice.

Explicit Analysis of the impacting plates to extract the contact forces and performing Frequency Response Analysis
using these forces as input to study the sound radiation by the plates.

This section presents optimized topology examples generated using OptiStruct. Each example uses a problem description, execution procedures, and results to demonstrate how OptiStruct is used as a design concept tool.

This section presents size (parameter) optimization examples solved using OptiStruct. Each example uses a problem description, execution procedures, and results to demonstrate how OptiStruct is used in size optimization.

This section presents shape optimization example problems, solved using OptiStruct. Each example uses a problem description, execution procedures and results to demonstrate how OptiStruct is used in shape optimization.

The examples in this section demonstrate how topography optimization generates both bead reinforcements in stamped
plate structures and rib reinforcements for solid structures.

The examples in this section demonstrate how the Equivalent Static Load Method (ESLM) can be used for the optimization
of flexible bodies in multibody systems.

The OptiStruct Example Guide is a collection of solved examples for various solution sequences and optimization types and provides
you with examples of the real-world applications and capabilities of OptiStruct.

Deals with requesting Modal Participation for a Modal Frequency Response analysis using
OptiStruct.

Modal Participation represents the complex contribution of a structure or a fluid mode to a
response at a particular frequency. Modal Participation is useful to diagnose low frequency
NVH problems, when the modes are well separated, i.e. the modal density is low.

The model used is a simplified car model with an acoustic cavity as shown in Figure 1. The model is already setup for a modal frequency
response run. The response point for Modal Participation is the node which approximates the
location of the Driver Ear in the acoustic cavity. The source of excitation is a unit load
in the Global Z direction at the Engine Block. When diagnosing NVH problems, user is
interested in peaks which in magnitude are above a certain pre-defined target level. So
instead of outputting Modal Participation at all solution frequencies, it is much more
efficient to request for data at frequencies for which the peak magnitudes violate
pre-defined NVH targets. This is accomplished by using PFMODE (output
request for Modal Participation) with PEAKOUT (request output data for
ānā number of peaks, where ānā can be changed by you).

FE Model

Element Types

CHEXA

CPENTA

CTETRA

CQUAD4

CTRIA3

CBUSH

CBAR

RBE2

The linear material properties are:

MAT1

For Steel

For Glass

For Seats

MAT10

For Acoustic Cavity

Results

The Modal/Panel Participation utility in HyperView is used to
post-process the results. You can choose the frequency at which the NVH issue is happening
and look at the Structure/Fluid modes contributing the most to it.