Exporting FEA Loads
About Exporting FEA Loads
You can export Adams View dynamic load information about any
rigid or
flexible body in your model to a finite element analysis (FEA) program for modeling and analysis. Adams View gives you the option to export complete load histories that include load information for all output steps in a
Simulation or export load information for only those
Output steps of interest. The FEA program uses the load information for a variety of purposes, such as stress and strain analyses.
You can export load information from Adams View in the following formats:
■ANSYS
■NASTRAN - either MSC Nastran or NX Nastran
■ABAQUS - SIMULIA from Dassault Systemes®
■MARC
■DAC or RPC III file formats (available with Adams Durability only)
Adams View calculates the loads on a desired body at the specified output steps in a simulation and exports the load information to a loads file. The loads file contains a series of load cases where the body is at an instantaneous dynamic equilibrium, such that the external (applied) forces and joint reactions are in balance with the inertial and gravitational forces. The loads file can be in any of the five formats listed above. After Adams View exports the file, you can use the loads file directly in the FEA program without any conversions or edit the file in a text editor, as desired.
See
Export - FEA Loads dialog box help.
Process for Exporting FEA Loads
When exporting dynamic load information, you perform the following general steps:
■Run a Simulation - Before exporting FEA loads, you need to run a
Simulation of your model so that Adams View can determine the loads acting on the bodies in the model. There is no special preparation needed for this simulation; you run it just like any other simulation.
■Identify the Body - You identify the body whose load information you want to export by specifying a
marker belonging to a
rigid body or directly selecting a
flexible body. For a rigid body, Adams View calculates all load information relative to the marker you select. Therefore, the marker’s location must correspond to the origin of the body as it appears in the FEA tool. For a flexible body, Adams View assumes that its FEA origin is unchanged.
■Find Load Points - After identifying a body whose load information is to be exported, Adams View finds all locations (load points) on the body that have external loads placed on them and displays the locations in a table. The node coordinate locations are displayed relative to the FEA origin of the body.
For a flexible body, Adams View also populates the table with the node IDs of the load points that correspond to the node IDs on the part in the FEA program. For a rigid body, you assign node IDs to the load points as explained next.
■Assign Node IDs to Load Points, if desired - For a rigid body, you can assign IDs to the load points that correspond to the node IDs on the part in the FEA program before exporting the load information. You can assign the IDs using either of two ways:
■Type the node IDs into the table in Adams View.
■Store the node IDs in a text file and have Adams View read the file. As Adams View reads a file, it associates the load points it found on the part with the node IDs and locations listed in the file. Adams View searches the file for node IDs with locations closest to the ones it found and fills the node IDs into the table in Adams View.
The node location file must be in the following format with commas (,) separating each element:
Node IDn, X, Y, Z
Node IDn+1, X, Y, Z
...
If your model contains several node IDs, you might want to create a text file of node IDs.
If you choose not to specify any node IDs, the FEA input file that is generated will contain the locations (with respect to the FEA coordinate reference) and ADAMS ID labels of the specified marker forces. You will need to replace the ADAMS ID labels with node IDs in the input file before submitting an analysis.
Limitations for Exporting FEA Loads
The following are limitations for exporting FEA loads from Adams View.
Redundant Constraints
You cannot export loads at the locations of redundant constraints. This is because Adams removes all redundant constraints in the simulation. Therefore, forces are not computed for these constraints. It is best to manually remove redundant constraints defined at a part before simulating if you want to export FEA loads.
Couplers and Gears
Loads due to couplers or gears are only exported on a part if the motion of that part is driving the coupler or gear. If, instead, the motion of the part is being driven by a coupler or gear, then the load resulting from that constraint will not be included in an FEA loads export of that part.
Friction
Reaction loads resulting from friction in joints are not supported. In fact, you receive an error if you attempt to export loads on joints that include friction.
Missing Result Set Components
Adams View exports an incomplete load set if
results of components defined on the part are missing from the simulation. This condition is checked and a warning message is issued for each component that does not have a result component. This usually happens when the computation of certain types of results, such as forces, is turned off.