Possible Errors when Using Adams View
The above are some common errors in Adams View.
For tips on how to build modeling objects so that you avoid problems when building or simulating your model, see:
Errors in Geometric Associativity
It is possible for you to create geometry or markers on the wrong part. If this occurs, your simulation results can be invalid. If geometry belongs to the wrong part, it can change the mass properties and, therefore, the dynamics of the model. If markers belong to the wrong part, you can get erroneous loads or connections.
To ensure that you assigned geometry and markers to the correct parts, do one of the following:
to check the connections of your parts.■Turn on icons during animations and watch carefully how markers move.
To assign geometry and markers to the correct part:
■Rename the markers so they belong to the correct part.
Errors as a Result of Mass Properties
Adams View automatically calculates mass and inertia properties for geometric bodies that you create in Adams View. It does not, however, assign mass and inertia properties to geometric bodies that you imported into Adams View. For example, it does not assign mass and inertia to IGES geometry that you imported.
To check and set mass and inertia:
■Use the Aggregate Mass command to perform a quick check of the total mass and inertia for your entire model or any subset of parts. Learn about Calculating Aggregate Mass of Parts.
■Use the Table Editor to display all parts in your model so you can perform a quick check of each part's mass and inertia and quickly fix the individual part masses and inertia. Learn about Editing Objects Using the Table Editor.
■Use the Modify command to check an individual part's mass and inertia and to change it as appropriate. Learn about modifying mass and inertia for rigid bodies in Modifying Part Properties.
Errors from Incorrect Gravity and Inconsistent Units
Make sure the magnitude and direction that you selected for gravity is appropriate for your model. In addition, make sure that the units that you are using are consistent throughout the model for:
■Time
■Geometric elements
■Mass
■Stiffness and damping
For example, often you set your length units in meters but data for bushing stiffness are given in Newtons per millimeters. In this case, you need to convert your units.
Also, be sure that the constants that you use in applied force expressions and user-written subroutines are consistent with the current set of Adams View units. Adams View does not change the units of constants if you change the default units settings.
In addition, make sure that you select a set of units that minimizes the difference in magnitude (scale) of all of your input data. For example, if you are modeling the vibration of a 75-ton industrial press, you might want to select mass = Kilopounds mass and displacement = inches.
If you divide the mass (about 150 klbm) by the expected vibration magnitude (1.5 inches), you obtain a model scale number of approximately 100, which is well within the range for an easy numerical solution. Using grams and meters in the same model would result in a scale number of about 109; other units would be even worse. Poorly scaled models can present numerical difficulties to Adams Solver, and you should avoid them.