How to Create Joints

2. The joint stack can be found by right clicking on the revolute joint icon .

3. Joints are used in ADAMS/View the describe how to two parts interact. They can be placed anywhere in your model.

4. When creating joints, it is important that they are applied in the correct plane. In ADAMS/View, it is possible to see your model from a variety of angles. To do this, right click somewhere in the ADAMS/View window that is clear of parts. You can choose from Front <F> (default view), Right <R>, Top <T> and Iso <I> (3D). After creating a joint, it is a good idea to check that the joint is indeed applied in the correct plane.

Types of Joints

I. Revolute/Rotational Joint

A Revolute/Rotational allows the rotation of one part with respect to another part about a common axis. Motion similar to a hinge joint can be represented by a revolute/rotational joint in ADAMS/View. To create a revolute joint:

1. Select the Revolute Joint tool

2. The default settings for a revolute joint are “One Location” and “normal to grid”, which describes the orientation of the joint. If the joint is applied in “One Location”, the part will be pinned to the ground, as opposed to “2 Bod-1Loc” which allows two parts to rotate about each other. If “Normal to Grid” is selected, the joint will be applied so that the pin is normal, or perpendicular, to the grid.

3. If the joint is for only one part, joined to the ground, click on that point and a revolute joint will be shown as an arrow around the point:

4. If the joint will connect two parts, change the setting to “2 Bod-1 Loc” or “2 Bod-2 Loc”. Click on part 1, part 2 and then the point of connection.

1. For examples of a revolute joint, see the Cam Tutorial or the Crank Slider Tutorial

II. Translational Joint

A translational joint allows one part to translate along a vector with respect to another part. The parts can only translate, not rotate, with respect to each other. As long as the axis is the proper direction, the location of a translational joint does not matter. The orientation of the translational joint, however, determines the direction of the axis along which the parts can slide with respect to each other. The direction of the motion of the translation joint is parallel to the orientation vector and passes through the location. To create a translational joint:

1. Select the Translational Joint tool from the joints tool stack.

2. The default settings for a translational joint are “One Location” and “Pick Feature”.

3. Click on the part that you want to translate.

4. A white arrow will show the direction that the part will translate. Click in the direction that you want the translation to occur and the translational joint will be shown:

2. For examples of a translational joint, see the Cam Tutorial or the Crank Slider Tutorial

III. Fixed Joint

A fixed joint locks two parts together so they cannot move with respect to each other. The effect is similar to combining two parts into a single part. If you want to have the two parts move relative to each other in a future analysis, simply delete the fixed joint and use another type of joint. For a fixed joint, the location and orientation of the joint often do not affect the outcome of the simulation. In these cases, you can place the joint at a location where the graphic icon is easily visible.

1. Select the Fixed Joint tool from the joints tool stack.

2. The default settings for a fixed joint are “One Location” and “Pick Feature”. If the joint is placed in one location, it will attach one part to the ground. ADAMS/View also gives the option of setting the joint to “Two Bod-1 Loc” and “Two Bod-2 Loc”. With fixed joints, the placement and direction are usually not important. The only exception would be in the case that a fixed joint allows force moments to become quite large depending on where you place the joint.

3. Click on the part or parts that are to remain fixed. The joint will be shown:

4. If only one part is picked, the part will be fixed to the ground. If two parts are at the location of the joint, ADAMS/View automatically applies the fixed joint to both parts. This means that both parts will be rigidly attached.

IV. Pin in Slot Joint

The pin-in-slot cam defines a point-to-curve constraint that restricts a fixed point defined on one part to lie on a curve defined on a second part. The first part is free to roll and slide on the curve that is fixed to a second part. The curve on the second part can be planar or spatial and open or closed. The first part cannot lift off the second part; it must always lie on the curve. When modeling a pin-in-slot mechanism, the pin-in-slot contact keeps the center of the pin in the center of the slot, while allowing it to move freely along the slot and rotate in the slot. To create a curve, use the spline tool. See Creating Geometry for more information.

1. Select the Pin in Slot Joint tool from the joints tool stack.

2. There are no default settings for the pin in slot joint because it is specifically used to simulate a pin in a slot.

3. Left click on the point that represents the pin. ADAMS/View will automatically snap to a point on the model. To create design points, see Creating Geometry. Left click on the spline that the pin is to be restricted to move along. It is important that the point picked is located at a point on the curve. A pin in slot joint will be shown at the location:

3. To see a detailed explanation of a Pin in Slot Joint, see the Cam tutorial

V. Cam Contact

A curve-on-curve cam restricts a curve defined on the first part to remain in contact with a second curve defined on a second part. The curve-on-curve cam is useful for modeling cams where the point of contact between two parts changes during the motion of the mechanism. The curves always maintain contact, even when the dynamics of the model might actually lift one curve off the other. You can examine the constraint forces to determine if any lift-off should have occurred. If your results require an accurate simulation of intermittent contact, you should model the contact forces directly using a vector force. The curve-on-curve cam models only one contact. Therefore, if the curves have contact at more than one point, you need to create a curve-on-curve cam for each contact, each with a initial condition displacement near the appropriate point.

1. Select the curve on curve Cam tool from the joints tool stack.

2. There are no default settings for the curve on curve cam joint because it is specifically used to simulate a curve on curve joint.

3. Left click on a curve that can be followed by another curve.

4. Select the curve along which the point or first curve will travel. The curve can be closed or open. Note that when you select a closed curve, the Dynamic Model Navigator highlights only a portion of the curve. ADAMS/View will use the entire curve.

To see a detailed explanation of a curve on curve joint, see the Cam tutorial