Creating Requests
You can create Requests to ask for standard displacement, velocity, acceleration, or force information that will help you investigate the results of your simulation. You can also define other quantities (such as pressure, work, energy, momentum, and more) that you want output during a simulation.
To learn more:
To define the output in which you are interested, you can specify:
Adams Solver generates the data at each Output step in a Simulation. For more on output steps, see Interactive Simulation Palette and Container.
Note: | Unlike measures, you must create requests before you run a simulation. Once you define them, you can use them with different simulations. |
By default, Adams View does not save the requested data to external files, but will save it to your modeling database. Learn about Solver Settings.
About Naming Results and Components in Requests
After a simulation, the data output from a request resides beneath an analysis in a results set. By default, the results set has the same name as the request and its components all have generic names, such as X, Y, and Z. If you set the output of the results to XML format (see Results (.res) Options), you can set the name of the results set and its components.
Learn more:
Results Set Naming
You can specify the name of the results set in which all result set components are placed. If there is an existing result set with this name, then the result set components are placed in that result set.
This is helpful if you want to group the output from multiple requests into a single results set. For example, you might have several different requests measuring driver input for a vehicle, and you might want to place them all within a result set named Driver_Inputs for easier viewing in Adams PostProcessor.
Component Naming
By default, there are eight components per results set, and they have generic names, such as X, Y, Z, and MAG. You can specify more descriptive names for them or specify a particular unit label or unit type associated with each component.
■Component Units - You can identify the unit dimension of the result set components. If you do not specify units, then the units of the components are predefined based upon standard request type (for example, displacement, velocity, and acceleration).
The units can be:
MASS | AREA |
TIME | VOLUME |
FORCE | TORQUE |
LENGTH | PRESSURE |
VELOCITY | DENSITY |
ACCELERATION | ENERGY |
ANGLE | TORSION_STIFFNESS |
ANGULAR_VELOCITY | TORSION_DAMPING |
ANGULAR_ACCELERATION | FREQUENCY |
INERTIA | AREA_INERTIA |
STIFFNESS | FORCE_TIME |
DAMPING | TORQUE_TIME |
■Component Labels - You can identify the labels to be used when plotting the result set components.
Using Naming to Delete Components
You can delete result set components from storage in the database by omitting them when you specify their names. For example, the following lists of names remove the first and fourth components from the result set:
””, X_Comp, Y_Comp, Z_Comp, ““, R1, R2, R3
This can be helpful if you want to reduce the memory overhead of the simulation data.
Creating Requests by Specifying Predefined Data Type and Marker
You can create a request by simply requesting predefined data and a marker with respect to which the output will be calculated. Learn about specifying predefined data to be output.
To create a request by specifying data type and marker:
1. Click the Design Exploration tab. From the Instrumentation container, click the Request tool 
.
.or
(Classic interface) From the Build menu, point to Measure, point to Request, and then select New.
The Create a Request dialog box appears.
2. Enter the name that you want assigned to the request.
3. In the Adams Id text box, assign a unique ID number to the request.
4. In the Comments text box, add any comments about the request to help you manage and identify the request.
5. If the output of the results set is XML format (see Results (.res) Options), set the naming for the results and components. Learn About Naming Results and Components in Requests.
■In the Components Name and Results Name text boxes, enter the names of the components and results. Separate the component names by commas.
■If desired, set the following to define a unit type or label associated with each of the components:
♦Component Labels, and then enter the labels to appear when plotting the result set components. Labels can be strings that include white space. Quotes must be used to define the string if special characters or white space are used.
6. Set the option menu to Define Using Type & Markers.
The elements of the dialog box change to those for entering a predefined data type and markers.
8. Specify the markers with respect to which the output will be calculated.
9. Select OK.
Creating Requests by Specifying Variables
You can identify one or more variables that represent the components associated with a request.
This option is only available if the format of the results files is set to XML. See setting Results (.res) Options.
To create a request:
1. Click the Design Exploration tab. From the Instrumentation container, click the Request tool .
.or
(Classic interface) From the Build menu, point to Measure, point to Request, and then select New.
The Create a Request dialog box appears.
2. Enter the name that you want assigned to the request.
3. In the Adams Id text box, assign a unique ID number to the request.
4. In the Comments text box, add any comments about the request to help you manage and identify the request.
5. If the output of the results set is XML format, set the naming for the results and components. Learn About Naming Results and Components in Requests.
■In the Components Name and Results Name text boxes, enter the names of the components and results. Separate the component names by commas.
■If desired, set the following to define a unit type or label associated with each of the components:
♦Component Labels, and then enter the labels to appear when plotting the result set components. Labels can be strings that include white space. Quotes must be used to define the string if special characters or white space are used.
6. Set the option menu to Define Using Variables.
The elements of the dialog box change to those for entering variables.
7. Enter the variables, separated by commas.
8. Select OK.
Creating Requests by Specifying Function Expressions
You can enter function expressions to specify output. Learn about specifying function expressions.
To create a request:
1. Click the Design Exploration tab. From the Instrumentation container, click the Request tool .
.or
(Classic interface) From the Build menu, point to Measure, point to Request, and then select New.
The Create a Request dialog box appears.
2. Enter the name that you want assigned to the request.
3. In the Adams Id text box, assign a unique ID number to the request.
4. In the Comments text box, add any comments about the request to help you manage and identify the request.
5. If the output of the results set is XML format, set the naming for the results and components. Learn About Naming Results and Components in Requests.
■In the Components Name and Results Name text boxes, enter the names of the components and results. Separate the component names by commas.
■If desired, set the following to define a unit type or label associated with each of the components:
♦Component Labels, and then enter the labels to appear when plotting the result set components. Labels can be strings that include white space. Quotes must be used to define the string if special characters or white space are used.
6. Set the option menu to Define Using Function Expressions.
The elements of the dialog box change to those for entering function expressions.
7. Enter function expressions in the boxes f2, f3, f4, f6, f7, and f8. Do no use f1 and f5. Adams Solver uses them to hold magnitudes for the three functions that follow. You do not need to enter a function in every text box.
8. Select OK.
Creating Requests by Specifying a Subroutine
You can enter subroutines to specify output. Learn about specifying subroutines.
To create a request by specifying data type and marker:
1. Click the Design Exploration tab. From the Instrumentation container, click the Request tool .
.or
(Classic interface) From the Build menu, point to Measure, point to Request, and then select New.
The Create a Request dialog box appears.
2. Enter the name that you want assigned to the request.
3. In the Adams Id text box, assign a unique ID number to the request.
4. In the Comments text box, add any comments about the request to help you manage and identify the request.
5. If the output of the results set is XML format, set the naming for the results and components. Learn About Naming Results and Components in Requests.
■In the Components Name and Results Name text boxes, enter the names of the components and results. Separate the component names by commas.
■If desired, set the following to define a unit type or label associated with each of the components:
♦Component Labels, and then enter the labels to appear when plotting the result set components. Labels can be strings that include white space. Quotes must be used to define the string if special characters or white space are used.
6. Set the option menu to Define Using Subroutines.
The elements of the dialog box change to those for entering subroutines.
7. In the User Function text box, enter parameters to the user-written subroutine REQSUB or specify an alternative library and name for the user subroutine in the Routine text box. (Learn about specifying routines with ROUTINE Argument.)
Enter the USER function using the following format where r1 through r30 are constants passed to the subroutine:
r1, ..., r30
8. If you specified to write an output file (.out), enter up to eight headings for columns of request output. Separate each heading with a comma (,).
Each heading can have as many as eight alphanumeric characters, including underscores (_). The first character in each heading must be alphabetic. You cannot use a comma (,), a semicolon (;), an ampersand (&), or an exclamation point (!).
If you do not want to specify a title for a particular column, use two quotation marks (" ") with no characters between them.
9. Select OK.
About Specifying Predefined Data To Be Output
You can choose to define Requests by specifying a predefined data type and one or more Markers with respect to which the data is returned. You can select the following types of data, which are commonly investigated quantities and are, therefore, predefined for you:
All information types are vectors, except for rotational displacements. Adams Solver internally calculates all data in the global coordinate system, although you can specify that the data be calculated and reported in another coordinate system.
Note that the units for rotational displacement data in the request output of the tabular output file default to degrees. The units for all other angular output data default to radians.
Displacement
When you request predefined displacement output, Adams Solver outputs the displacement of a specified marker (I marker) with respect to a second marker (J marker). When you select displacement data, Adams Solver generates eight channels of output as follows:
■Time (Time)
■Translational magnitude (Mag)
■X component (X)
■Y component (Y)
■Z component (Z)
■Psi angle (Psi)
■Theta angle (Theta)
■Phi angle (Phi)
The psi, theta, and phi angles are Euler or body-fixed 313 rotations of the I marker with respect to the J marker. Adams Solver calculates the displacement data in the global coordinate system. If you specify a reference marker, Adams Solver resolves the translational x, y, and z components in the coordinate system of the reference marker. The reference marker does not affect psi, theta, and phi.
Rotational displacement information differs from all other standard output. Whether this information is in psi, theta, and phi coordinates or in yaw, pitch, and roll coordinates, the rotation sequence is not a vector. As a result, Adams Solver outputs no magnitude column. In addition, the sequence of coordinates is independent of any frame external to the I and the J markers. The reference marker has no effect on the angular coordinates.
Velocity
When you request predefined velocity output, Adams Solver outputs the velocity of the first marker that you specify (I marker) with respect to a second marker (J marker). When you request velocity data, Adams Solver generates nine headings and nine columns of data. The nine columns include:
■Time (Time)
■Translational magnitude (Vm)
■Translational x component (Vx)
■Translational y component (Vy)
■Translational z component (Vz)
■Rotational magnitude (Wm)
■Rotational x component (Wx)
■Rotational y component (Wy)
■Rotational z component (Wz)
Adams Solver calculates this velocity data (the first derivative of the displacement of the I marker with respect to the J marker) in the global coordinate system. If you specify a reference marker, Adams calculates the translational and rotational x, y, and z components in the coordinate system of the reference marker.
Acceleration
When you request predefined acceleration output, Adams Solver outputs the acceleration of the I marker with respect to the J marker. This argument generates nine headings and nine columns of output. The columns include:
■Time (Time)
■Magnitude of translational acceleration (Accm)
■Translational x component (Accx)
■Translational y component (Accy)
■Translational z component (Accz)
■Magnitude of rotational acceleration (Wmdot)
■Rotational x component (Wxdot)
■Rotational y component (Wydot)
■Rotational z component (Wzdot)
Adams Solver calculates the acceleration data (the second derivative of the displacement of the I marker with respect to the J marker) in the global coordinate system. If you specify a reference marker, Adams Solver calculates the translational and rotational x, y, and z components in the coordinate system of the reference marker.
Force
When you request predefined force output, Adams Solver outputs the force associated with the I and the J markers or outputs the action-only forces on the I marker if you specify the I marker. When you specify both the I and the J markers, Adams Solver sums the forces on the I marker due to those forces associated with the I and the J markers. These forces can include both applied forces (such as Translational Spring Dampers and Bushings) and reaction forces from constraints (such as Joints and Motions).
When you specify only the I marker, Adams Solver sums all of the action-only forces that are applied to the I marker. If you specify a reference marker, Adams Solver reports the components of the resulting vectors in the reference frame of the reference coordinate system. If you do not specify a reference marker, Adams Solver reports the components in the ground coordinate system.
Adams Solver outputs nine columns of data:
■Time (Time)
■Translational force magnitude (Fmag)
■Three components of translational force (Fx, Fy, and Fz)
■Rotational force (torque) magnitude (Tmag)
■Three components of torque (Tx, Ty, and Tz)
Applied forces and torques are those generated by Beams, bushings, Field Elements, Single-Component Forces, and spring-dampers. Adams Solver outputs the applied forces and torques acting at the request I marker (which can be either the applied force I marker or the applied force J marker). The magnitude and point of force application on the part containing the applied force J marker varies according to the type and source of the force:
■For spring-dampers and action-reaction single-component forces, the forces and torques acting at the J marker are equal and opposite to the forces and torques acting at the I marker.
■For action-only, single-component forces, there is no force or torque acting at the applied force J marker.
■For beams, fields, and bushings, the forces acting at the applied force J marker are equal and opposite to the forces acting at the applied force I marker. As long as the applied force I marker and the applied force J marker are coincident, the torques acting at the applied force J marker are equal and opposite to the torques acting at the applied force I marker. If there is a finite separation between the I and the J markers, the torques acting at the applied force J marker are opposite, but not equal, to the torques acting at the applied force I marker.
Reaction forces and torques are those generated by constraint-inducing elements. For revolute, spherical, and universal joints and for orientation, parallel axes, and perpendicular joint primitives, Adams Solver outputs the reaction forces and torques acting at the request I marker (which can be either the constraint I marker or the constraint J marker). The force and torque acting at the request J marker are equal and opposite to the force and torque acting at the request I marker. Depending on the type of constraint, some or all of the torques acting at the I marker are zero.
You must be careful when requesting a force with the I and the J markers reversed from those specified in the force-producing element. Adams Solver reports the force as if it were applied to the J marker of the force-producing element. The translational force on the J marker of the force element will be equal and opposite to the translational force on the I marker of the force element if it is not action only. The force will be zero if it is action only.
The torque on the J marker of the force element has an extra component that can have significance. The torque is the sum of two contributions. The first contribution is the opposite of the torque on the I marker. The second contribution is due to the force acting across the separation between the I and the J markers. If the force acts along the line of sight of the two markers, this extra torque will be zero. To minimize misunderstandings, attach your request markers in the same order as the markers on the force-producing element.
About Specifying a Subroutine
In requests, you can enter parameters that are passed to the user-written Adams Solver User-written subroutine REQSUB that is linked to Adams View as a dynamic-linked library. For more information on REQSUB and passing parameters to subroutines, see Adams Solver online help. Also refer to the appropriate instructions on creating and running the library you make in Running and Configuring Adams.
About Specifying Function Expressions
You can specify up to six function Expressions in one request. The function expressions are labeled f1 through f8, with f1 and f5 reserved by Adams Solver to hold the magnitude of the function expressions that follow.
Creating function expressions to define requests provides you with two significant advantages over specifying a predefined data type and marker. The advantages are:
■You can customize the expressions to output just what you want and are, therefore, more versatile.
■The function expressions are very efficient, calculating in one or two requests what otherwise might require eight or more requests.
The following example illustrates how to output quantities that could not be captured using predefined outputs, especially not all within a single request:
f1 = (blank)
f2 = "0.5*17.49*VM(mar15, mar27)**2"
f3 = "FX(mar18, mar19, mar1)*DX(mar18, mar19, mar1)"
f4 = "FX(mar18, mar19, mar1)/TIME"
f5 = (blank)
f6 = "AZ(mar7, mar8)"
f7 = "JOINT(joi26, mar7, fy, mar99)"
f8 = "MOTION(joi26, mar7, tz, mar99)"
The easiest way to enter a function expression in Adams View is to use the Function Builder. For more information on the Function Builder and the built-in functions, see the Adams View Function Builder online help.