force modify element_like rotational_spring_damper
Allows modification of the rotational spring damper object.
Format:
force modify element_like rotational_spring_damper |
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spring_damper_name = | existing spring damper force |
new_spring_damper_name = | new spring damper force |
Adams_id = | integer |
comments = | string |
damping = | real number |
stiffness = | real number |
preload = | real number |
displacement_at_preload = | real number |
i_marker_name = | existing marker name |
j_marker_name = | existing marker name |
Example:
force modify element_like rotational_spring_damper & |
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spring_damper_name = | SPRING_1 & |
new_spring_damper_name = | SPRING_2 & |
Adams_id = | 2 & |
comments = | comment & |
damping = | 0.5 & |
stiffness = | 0.2 & |
preload = | 1.2 & |
displacement_at_preload = | 0.02 & |
i_marker_name = | marker_1 & |
j_marker_name = | marker_2 |
Description:
Parameter | Value Type | Description |
|---|
spring_damper_name | An Existing Spring-damper Force | Specifies the spring-damper force to modify. You use this parameter to identify the existing spring-damper to affect with this command. You may identify a spring-damper force by typing its name or by picking it from the screen. |
new_spring_damper_name | A New Spring-damper Force | Specifies the name of the new spring-damper force. You may use this name later to refer to this spring-damper.Adams View will not allow you to have two spring-dampers with the same full name, so you must provide a unique name. |
Adams_id | Integer | Specifies an integer used to identify this element in the Adams data file. |
comments | String | Specifies comments for the object being created or modified. |
damping | Damping | Specifies the viscous damping coefficient for the spring damper. |
stiffness | Stiffness | Specifies the spring stiffness coefficient for the spring damper. |
preload | Force | Specifies the reference force or torque for the spring. This is the force the spring exerts when the displacement between the I and J markers is equal to DISPLACEMENT_AT_PRELOAD (the reference length of the spring). |
displacement_at_preload | Length | Specifies the reference length for the spring. If PRELOAD (the reference force of the spring) is zero, DISPLACEMENT_AT_PRELOAD equals the free length |
i_marker_name | An Existing Marker | Specifies a marker on the first of two parts connected by this force element. Adams View connects this element to one part at the I marker and 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 force element. Adams View connects this element to one part at the I marker and to the other at the J marker. |
Extended Definition:
1. The springdamper force applies a rotational or a translational spring-damperbetween two markers. For a rotational spring-damper, the z-axis of the I markerand the z-axis of the J marker must be parallel and must point in the samedirection. Because the spring- damper force is always an action-reaction force, thedirection of the translational force is the line of sight between the I and the Jmarkers. Thus, if the force is positive, the markers experience a repelling forcealong this line, and if the force is negative, the markers experience an attractingforce. The magnitude of the translational force applied to the parts containing thetwo markers is linearly dependent upon the relative displacement and velocity ofthe two markers. The following linear constitutive equation describes the forceapplied at the I marker:
force = -C*db/dt - K*(b-LENGTH) + FORCE
2. Adams automatically computes the terms db/dt and b. The force value is the force on the I marker from the J marker; the force on the J marker is equal and opposite. The term b is the distance between the I and the J markers. Adams assumes that b is always greater than zero. The following linear constitutive equation describes the torque applied at the I marker:
torque = -CT*da/dt - KT*(a-ANGLE) + TORQUE
3. Adams automatically computes the terms da/dt and a. The torque is applied to the I marker about the positive z-axis of the I marker; the torque on the J marker isequal and opposite to the torque on the I marker. The right-hand rule defines apositive torque. The term a is the angle between the x-axes of the I and the Jmarkers. Adams takes into account the total number of complete turns.
Considerations:
If the z-axis of the I marker is not parallel to, and/or not pointed in the samedirection as, the z-axis of the J marker for a rotational spring-damper, theresults are unpredictable.
Since the line-of-sight method determines the direction of a translationalspring-damper force, the I and the J markers cannot be coincident.
4. You may identify a spring-damper force by typing its name or by picking it from the screen. If the spring-damper force is not visible on the screen, you must type the name. You may also find it convenient to type the name even if the spring-damper is displayed. If you created the spring-damper force by reading an Adams data set, the spring-damper name is the letters SPR followed by the Adams data set spring-damper ID number. The name of Adams SPRINGDAMPER/101 is SPR101, for example. If you created the spring-damper during preprocessing, you gave it a name at that time. If a spring-damper 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 spring-damper under a different model, for instance, you may need to enter the model name as well. For example, you may specify spring-damper 'left' from model 'sla' by entering ".sla.left". You must separate multiple spring-damper names by commas. If the spring-damper 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 spring-damper picks by commas.
5. Normally, entity names 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 (e.g. 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.
6. 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, internallygenerated 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.
7. 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.
Tips:
■If you type a "?", Adams View will list the spring-dampers available by default.