constraint modify joint screw
Allows the modification of an existing screw joint.
Format:
constraint modify joint screw |
|---|
joint_name = | an existing joint |
new_joint_name = | a new joint |
adams_id = | integer |
comments = | string |
i_marker_name = | an existing marker |
j_marker_name = | an existing marker |
pitch = | real number |
Example:
constraint modify joint screw & |
|---|
joint_name = | JOINT__1 & |
new_joint_name = | JOINT__2 & |
adams_id = | 2 & |
comments = | "comment string" & |
i_marker_name = | marker_1 & |
j_marker_name = | marker_2 & |
pitch = | 0.22 |
Description:
Parameter | Value Type | Description |
|---|
joint_name | An Existing Joint | Specifies the joint to modify. |
new_joint_name | A New Joint | Specifies the name of the new joint. You may use this name later to refer to this joint. |
adams_id | Adams_id | Specifies an integer used to identify this element in the Adams data file. |
comments | String | Specifies comments for the object being created or modified. |
i_marker_name | An Existing Marker | Specifies a marker on the first of two parts connected by this joint. Adams View connects one part at the I marker to the other at the J marker. |
j_marker_name | An Existing Marker | Specifies a marker on the second of two parts connected by this joint. Adams View connects one part at the I marker to the other at the J marker. |
pitch | Length | Specifies the pitch of the scew joint. |
Extended Definition:
1. For a screw joint, the z-axis of the I marker and the z-axis of the J marker must always be parallel and co-directed. Although the screw joint does not enforce this parallelism, the chain of parts and joints that connects the two markers should.
During simulation, the I marker displacement along the J marker z-axis is a function of the relative angle of the x-axis of the I marker with respect to the x-axis of the J marker. Adams measures a positive rotation according to the righthand rule. For every full rotation, the displacement of the I marker along the z-axis of the J marker is equal to the value of the screw pitch. If phi is zero, the translational displacement may be zero or any multiple of the pitch.
2. You may identify a joint by typing its name or by picking it from the screen. If the joint is not visible on the screen, you must type the name. You may also find it convenient to type the name even if the joint is displayed. If you created the joint by reading an Adams data set or graphics file, the joint name is the letters JOI followed by the Adams data set joint ID number. The name of Adams JOINT/101 is JOI101, for example. If you created the joint during preprocessing, you gave it a name at that time. If a joint is available by default, you may identify it by entering its name only. If it is not, you must enter its full name. To identify a joint under a model, for instance, you may need to enter the model name as well. For example, you may specify joint 'lower_pivot' in model 'links' by entering ".links.lower_pivot". You must separate multiple joint names by commas. If the joint is visible in one of your views, you may identify it by picking on any of the graphics associated with it. You need not separate multiple joint picks by commas.
3. Normally, entity names like the joint name are composed of alphabetic, numeric, or '_' (underscore) characters, and start with an alphabetic or '_' character. They may be any length. For more information, see
Using Extended Names. By enclosing the name in double quotes, you may use other printable characters, or start the name with a numeral. If a name contains characters, or starts with a numeral, you must always quote the name when entering it. Note that you can specify the parentage of an entity (for example, what part "owns" a marker or a geometry element) when you CREATE it by changing the name. If you enter just the entity name, then the default parent will be assigned by Adams View. If you type in the full name, then you may over ride the default parent. In most cases, when creating an entity, Adams View will provide a default name. The default name that Adams View provides will specify the parentage that it has assumed. You may, or course, delete this name and use your own. The form of a full name is:
"...._NAME.GRAND_PARENT_NAME.PARENT_NAME.ENTITY_NAME"
The number of levels used varies from case to case and the parentage must exist before an entity can be assigned to it.
4. When you use the FILE ADAMS_DATA_SET WRITE command, Adams View writes an Adams data file for your model. Adams requires that each modeling element be identified by a unique integer identifier. If you use this parameter to specify a non-zero identifier, Adams View will use it in the corresponding statement in the Adams data file. You may also enter zero as an identifier, either explicitly or by default. The next time you write an Adams file, Adams View will replace the zero with a unique, internally-generated identifier. Adams View will permanently store this identifier with the element just as if you had entered it yourself. Normally, you would let all identifiers default to zero, and Adams View would generate the identifiers for you. You are never required to enter a non-zero identifier. You only need to specify it if, for some reason, you wish to control the Adams file output.
5. When an Adams Solver data file (.adm) is read into Adams View, all comments associated with a statement (from the end of the previous statement through the end of the current statement) are stored with the object. Comments in the data file can be associated with model. These comments must follow the title statement and be followed by the comment 'END OF MODEL COMMENTS'. This string must be uppercase. When an Adams Solver data file is written, the comments for an object are written before the statement corresponding to the object.
6. A screw joint is a five-degree-of-freedom joint that constrains the rotational and translational displacement of the I marker as it spins about the z-axis of the J marker.
Tips:
1. If you type a "?", Adams View will list the joints available by default.
2. Use the joint_name parameter to identify the existing joint to affect with this command.
3. Adams View will not allow you to have two joints with the same full name, so you must provide a unique name.