NVH Composer

NVH Composer provides a simplified interface for defining the topological relationships between parts and subassemblies that together form a complex assembly such as a full vehicle. The interface consists of an interactive layout view that lets you add and define components, universal connections, and lumped mass trim information. When you define the full vehicle layout, you can start the assembly creation process. The assembly is created in Pre/Post and connected to the NVH Composer layout view, which allows you to change connection settings in both Pre/Post and NVH Composer and synchronize your changes.

NVH Composer application window

The NVH Composer application window lets you graphically define the topology of your assembly using an interactive layout view and several tabbed views for defining project, component, and connection options.

NVH Assembly Composer layout view (1), Project view for setting project options and Definition view for setting component and connection options (2), Connection DB view (read only) and Mass List view (for managing lumped mass connections) (3), assembly component (4), assembly connection (5), invalid assembly connection (6) invalid assembly component (7)

Defining components and connections

To define components, you can use Pre/Post FEM or assembly FEM files, or meshes using Nastran input files. When you add meshes using Nastran input files, NVH Composer creates new FEM files.

To define connections, you can use the same universal connections that you can create in Pre/Post. NVH Composer supports the following connection types:

• Bolt

• Spring

• Latch, which corresponds to the Spring universal connection.

• Bushing

• Bump Stop, which corresponds to the Bushing universal connection.

• Kinematic

• Weather Strip, which corresponds to the Sealing universal connection.

• Seam Weld

All connections are modeled in Nastran.

To connect components, you add a connection, and then select the components when you define the connection properties. Defining connections in NVH Composer requires that you have the following:

• A connections database that contains sets of properties for universal connections and their elements, such as stiffness.For more information, see NVH Composer connections database.

• A connection point or the name of a hard point that identifies the target location of each universal connection. A connection point is defined by coordinates.Hard points is the automotive industry term for points that are used for boundary conditions. In NVH Composer, the hard points are used as target locations to create a nodal universal connection. You can create hard points using selection recipes as explained in Exporting selection recipes as hard points. When you define a nodal connection in NVH Composer, you enter the name of the hard point as it exists in the exported selection recipe.

NVH Composer folders and project files

You can import several different files into NVH Composer to quickly create your assembly. To use these files and to generate your NVH assembly FEM file, NVH Composer relies on a specific folder set up. For information on the files you can import, the files NVH Composer generates, and the required folder set up, see Setting up folders and files for NVH Composer.

Checking your assembly

To identify components or connections whose setup is incomplete, and connections whose PIDs are invalid or missing, use the Check Assembly command . The Check Assembly command displays the invalid components and connections in red in the layout and Mass List views.

For connections with invalid or missing PIDs, you can use the following commands to find and replace the PIDs.

Command	Description
Search PIDs	Finds all connections that are missing all of their PIDs and updates the connections with the missing PIDs. The updated connections and the new PIDs are listed in the Assembly Composer Search All PIDs Report. Note: This command does not find connections that are missing only some PIDs.
Search All PIDs	For an individual connection, finds replacement PIDs for missing and invalid PIDs. The Assembly Composer PID list dialog box opens with a list of the replacement PIDs. To replace the PIDs with those listed in the dialog box, click Replace PIDs. Note: Depending on the PIDs that are missing or invalid, the Assembly Composer Search All PIDs Report might open instead of the Assembly Composer PID list dialog box.

To view a report of the components, connections, and lumped mass connections, use the Create Report command.

Generating your assembly

Once you define the assembly topology in NVH Composer and validate the components and connections, you can generate the assembly in either of the following ways:

• Interactively from NVH Composer using the Launch Assembly Composer Automation command.

• Directly from Pre/Post using the Assembly Composer Automation command and a previously defined project.

Updating and checking your NVH assembly

After your assembly FEM file is generated, you can use NVH Composer to do the following:

• Update the connection settings in Pre/Post and/or in NVH Composer, whichever is most convenient for you. For example, you might change some universal connection settings in Pre/Post and some in NVH Composer. When you do that, you can use the NVH Composer Synchronize command to select which updates you want to retain and the direction in which you want to push them—from NVH Composer to Pre/Post or from Pre/Post to NVH Composer.The Synchronize command automatically generates a report of all of your changes.

• Use the NVH Composer project files as templates so that you can quickly create a new assembly FEM file. You can update the project files and generate an updated assembly FEM file in the NVH Composer application or directly using Assembly Composer Automation

Quality audit checks

In addition to the validation checks in the NVH Composer application, NVH Composer checks the following during the assembly FEM creation process:

• Labeling—For each component, NVH Composer identifies the starting and ending ID of nodes, elements, properties, and axis systems. In addition, NVH Composer identifies whether conflicts exist, and if so, whether the conflicts are internal to the component or in the assembly.

• Connection tolerances—NVH Composer is integrated with the Quality Audit tool, which allows NVH Composer to use your specific tolerance settings to detect possible issues with the connections you created. Note: The connections must be created in NVH Composer. NVH Composer cannot check new connections that you create in Pre/Post.

NVH Composer writes the results of these checks to an AssemblyChecks.xls file in the Output folder.

If you create a customized file of your Quality Audit tool settings, you must update the following file with the location of the file:

**..\wntx64\kits\simulation\asmutilities\application**AsmComposerTool_Config.xml

Note:

The AsmComposerTool_Config.xml file is set to read only.

For information on the types of connections checks and the corresponding settings, see Quality audits for connections. For information on creating a customized file of your settings, see Reuse your settings for connection checks.

Where do I find it?

Opening NVH Composer

Application	Pre/Post
Prerequisites	A FEM file or assembly FEM file as the work part and displayed partSimcenter Nastran as the specified solver
Command Finder	Assembly Composer Application

Creating an NVH assembly by importing NVH Composer definition and connection database files

Application	Pre/Post
Prerequisites	A FEM file or assembly FEM file as the work part and displayed partSimcenter Nastran as the specified solver
Command Finder	Assembly Composer Automation

How do I

Create an NVH Composer project

Open an assembly FEM file and NVH Composer project files

Check and fix your NVH assembly

Synchronize assembly connection updates

Learn more

NVH Composer workspace

NVH Composer workflow

Setting up folders and files for NVH Composer

NVH Composer connections database

Quick links

Command reference

Pre/Post video examples

Bulk Entry Descriptions

Simcenter 3D tutorials

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NVH Composer, Simcenter 3D 2021.1 Series

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