Getting Started Using Adams Car
About Modal Flexibility in Adams Car
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Geometry (location of nodes and node connectivity)
Nodal mass and inertia
Mode shapes
Generalized mass and stiffness for modal shapes
Alternatively, instead of specifying the MNF, the flexible body can also be created using MD DB, available
in MD solution. Using this, the user can instruct MD Nastran to create an MD DB that can be used by MD
Adams to create flexible bodies. The following are the highlights of this feature:
1. Multiple flexible bodies can be stored in one single database.
2. One database file is needed: .MASTER.
3. When multiple bodies presented in the database, user needs an additional parameter, INDEX, to
create a flexible body. User can browse the contents of a database and get the index of a body through
Adams Flex Toolkit.
4. It takes advantage of sophisticated Nastran Database access technology.
5. The database is platform-dependent.
When you integrate a flexible body into a template, you have to supply the following:
A modal neutral file. This means that the MNF should have been previously created and stored in a
shared or private database or the MD DB should present.
Location and orientation information for the part that you will create. Adams Car uses the location
and orientation information to rigidly rotate and translate the flexible body.
Inertia coupling and the damping ratio.
You can now integrate flexible bodies into your subsystems or assemblies. The process of swapping rigid bodies
with flexible bodies is fast, easy, and convenient, it eliminates the need for multiple templates, and is fairly
automatic. With rigid-to-flexible swapping, modal flexibility becomes a property of the body. When you
integrate a flexible body into a subsystem, you must:
Supply a modal neutral file. This means that the MNF should have been previously created and
stored in a shared or private database or the MD DB should present.
Position the flexible body with respect to the rigid parts. For help, from the Adjust menu, point to
General Part, select Rigid to Flex, and then press F1.
Monitor the connectivity. For help, from the Adjust menu, point to General Part, select Rigid to
Flex, and then press F1.
To successfully integrate a flexible body into an Adams Car template or subsystem and run simulations,
consider these precautions:
Use flexible bodies if a component flexibility affects the dynamic behavior of your model or if you
are interested in accurate deformations of the flexible body under various load conditions.
Because flexible body deformations are a linear combination of deformation shapes, be careful when
modeling components undergoing high nonlinear deformations.
Consider the computational load that a flexible body representation demands, especially if the MNF
description is very detailed, that is, if several modes have been included.