Applying Point Motion
About Point Motion
There are two types of Point Motion that you can create:
■Single point motion - Prescribes the motion of two parts along or around one axis.
■General point motion - Prescribes the motion of two parts along or around the three axes (six degrees of freedom (DOF)).
When you create a point motion, you specify the parts to which the motion is to be applied and the location and orientation of the motion. Adams View creates markers on each part at the location of the motion. The marker that Adams View creates on the first part you select is called the moving point. It moves or rotates relative to the marker on the second part, called the reference point. The z-axis of the reference point defines the positive direction using the right-hand rule.
When you create a point motion, Adams View creates a motion at the specified location.
■For a single point motion, Adams View defines the motion as a constant velocity over time, based on a speed value that you can enter. The speed value can be a numerical value, function expression, or User-written subroutine, as explained in Defining the Motion Magnitude.
By default, Adams creates the point motion around or along the z-axis. You specify the direction of the z-axis when you create the single point motion. You can change the axis around or along which the motion is applied.
■For a general point motion, Adams View creates a motion around or along all six coordinates of the markers created on the selected parts. It does not define the magnitude of the motion. You’ll need to modify the motion to define its magnitude.
Creating Point Motions Using the Motion Tools
Learn about applying point motion as you modify joints in Imposing Point Motion on a Joint.
To create a point motion:
1. From the Joint palette, select the tool representing the type of point motion that you want to create. Select either:
■
to create a single point motion.
to create a single point motion.■
to create a general point motion.
to create a general point motion. 2. In the settings container, specify the following:
How you want the motion applied to parts. You can select the following:
■1 Location - Lets you select the location of the motion and have Adams View determine the two parts to which it should be applied. Adams View selects the parts closest to the motion location. If there is only one part near the motion, Adams View connects the motion to that part and ground.
■2 Bodies - 1 Location - Lets you explicitly select the two parts to which the motion is to be applied and the location of the motion.
■2 Bodies - 2 Locations - Lets you explicitly select the two parts to which the motion is to be applied and the location of the motion on each part. You should use this option if you are working in exploded view. For more on exploded view, see Initial Conditions Tool.
For more on the effects of these options, see Connecting Constraints to Parts.
How you want the motion oriented. You can select:
■Normal to Grid - Lets you orient the motion along the current working grid, if it is displayed, or normal to the screen.
■Pick Geometry Feature - Lets you orient the motion along a direction vector on a feature in your model, such as the face of a part.
3. If you are creating a single point motion, set Characteristic to the direction of the motion, and then enter the speed of the motion in the Speed text box.
4. If you selected to explicitly select the parts to which the motion is to be applied, select each part using the left mouse button.
5. Place the cursor where you want the motion to be located and click the left mouse button. If you selected to specify its location on each part, place the cursor on the second location, and click the left mouse button.
6. If you selected to orient the joint along a direction vector on a feature, move the cursor around in your model to display an arrow showing the direction in which you want the motion oriented. When the direction vector shows the correct orientation, click the left mouse button.
Modifying Single Point Motion
The following procedure explains how to modify a single Point Motion defined between two parts.
Note: | You can also modify point motion using the Table Editor. |
To modify a single point motion:
1. Display the modify motion dialog box as explained in Accessing Modify Dialog Boxes.
The Point Motion dialog box appears.
2. If desired, in the Moving Point and Reference Point text boxes, change the markers that define the location and orientation of the motion on the parts.
Tips on Entering Object Names in Text Boxes.
3. Set Type to how you want to define the magnitude of motion:
If you selected Function, enter the following in the Function (time) text box that appears:
■Numerical value (For rotational motion, specify the magnitude in radians.)
■Function expression
To enter a function expression, next to the Function (time) text box, select the More tool 
to display the Adams View Function Builder. For information on using the Function Builder, see Function Builder and Adams View Function Builder online help.
to display the Adams View Function Builder. For information on using the Function Builder, see Function Builder and Adams View Function Builder online help.■If you selected Subroutine, enter the parameters to be passed to a user-written subroutine and its ID.
4. Set Type to Displacement, Velocity, or Acceleration to specify how motion magnitude is defined.
5. In the Displacement IC or Velocity IC text boxes, enter the initial conditions for displacement or velocity.
■Initial displacement defines the translation of the first part in units of length relative to the second part. You can set displacements on any point motion whose magnitude is defined as velocity or acceleration.
■Initial velocity defines the velocity of the first part with respect to the second part in units of length per unit of time. You can set initial velocity on any point motion whose magnitude is defined as acceleration.
Modifying General Point Motion
The following procedure explains how to modify a general Point Motion defined between two parts.
Note: | You can also modify point motion using the Table Editor. |
To modify a general point motion:
1. Display the modify motion dialog box as explained in Accessing Modify Dialog Boxes.
The Impose Motion(s) dialog box appears.
2. If desired, in the Moving Point and Reference Point text boxes, change the markers that define the location and orientation of the motion on the parts. Learn about moving and reference points.
Tips on Entering Object Names in Text Boxes.
3. Set Type to how you want to define the magnitude of motion.
4. Enter the following in the F(time) text boxes. The text boxes that appear depend on how the magnitude of the motion is defined.
■Numerical value (For rotational motion, specify the magnitude in radians.)
■Parameters to be passed to a User-written subroutine MOTSUB or you can specify an alternative library and name for the user subroutine in the Routine text box. See the Subroutines section of the Adams Solver online help. Learn about specifying your own routine with ROUTINE Argument.
To enter a function expression, next to the Function (time) text box, select the More tool to display the Function Builder.
to display the Function Builder. 5. In the Disp. IC or Velo. IC text boxes, enter the initial conditions for displacement or velocity. The text boxes that appear depend on how the magnitude of the motion is defined.
■Initial displacement defines the translation of the first part in units of length relative to the second part. You can set displacements on any point motion whose magnitude is defined as velocity or acceleration.
■Initial velocity defines the velocity of the first part with respect to the second part in units of length per unit of time. You can set initial velocity on any point motion whose magnitude is defined as acceleration.