Modelica.Mechanics.Rotational.Interfaces

Connectors and partial models for 1D rotational mechanical components

Information

This package contains connectors and partial models for 1-dim. rotational mechanical components. The components of this package can only be used as basic building elements for models.

Extends from Modelica.Icons.InterfacesPackage (Icon for packages containing interfaces).

Package Content

Name	Description
Flange	One-dimensional rotational flange
Flange_a	One-dimensional rotational flange of a shaft (filled circle icon)
Flange_b	One-dimensional rotational flange of a shaft (non-filled circle icon)
Support	Support/housing flange of a one-dimensional rotational shaft
InternalSupport	Adapter model to utilize conditional support connector
PartialTwoFlanges	Partial model for a component with two rotational 1-dim. shaft flanges
PartialOneFlangeAndSupport	Partial model for a component with one rotational 1-dim. shaft flange and a support used for graphical modeling, i.e., the model is build up by drag-and-drop from elementary components
PartialTwoFlangesAndSupport	Partial model for a component with two rotational 1-dim. shaft flanges and a support used for graphical modeling, i.e., the model is build up by drag-and-drop from elementary components
PartialCompliant	Partial model for the compliant connection of two rotational 1-dim. shaft flanges
PartialCompliantWithRelativeStates	Partial model for the compliant connection of two rotational 1-dim. shaft flanges where the relative angle and speed are used as preferred states
PartialElementaryOneFlangeAndSupport2	Partial model for a component with one rotational 1-dim. shaft flange and a support used for textual modeling, i.e., for elementary models
PartialElementaryTwoFlangesAndSupport2	Partial model for a component with two rotational 1-dim. shaft flanges and a support used for textual modeling, i.e., for elementary models
PartialElementaryRotationalToTranslational	Partial model to transform rotational into translational motion
PartialTorque	Partial model of a torque acting at the flange (accelerates the flange)
PartialAbsoluteSensor	Partial model to measure a single absolute flange variable
PartialRelativeSensor	Partial model to measure a single relative variable between two flanges
PartialFriction	Partial model of Coulomb friction elements

Modelica.Mechanics.Rotational.Interfaces.Flange

One-dimensional rotational flange

Information

This is a connector for 1D rotational mechanical systems. It has no icon definition and is only used by inheritance from flange connectors to define different icons.

The following variables are defined in this connector:

phi: Absolute rotation angle of the flange in [rad].
tau: Cut-torque in the flange in [Nm].

Contents

Modelica.Mechanics.Rotational.Interfaces.Flange_a

One-dimensional rotational flange of a shaft (filled circle icon)

Information

This is a connector for 1-dim. rotational mechanical systems and models which represents a mechanical flange of a shaft. The following variables are defined in this connector:

phi: Absolute rotation angle of the shaft flange in [rad].
tau: Cut-torque in the shaft flange in [Nm].

There is a second connector for flanges: Flange_b. The connectors Flange_a and Flange_b are completely identical. There is only a difference in the icons, in order to easier identify a flange variable in a diagram. For a discussion on the actual direction of the cut-torque tau and of the rotation angle, see section Sign Conventions in the user's guide of Rotational.

If needed, the absolute angular velocity w and the absolute angular acceleration a of the flange can be determined by differentiation of the flange angle phi:

w = der(phi);
a = der(w);

Extends from Flange (One-dimensional rotational flange).

Contents

Modelica.Mechanics.Rotational.Interfaces.Flange_b

One-dimensional rotational flange of a shaft (non-filled circle icon)

Information

This is a connector for 1-dim. rotational mechanical systems and models which represents a mechanical flange of a shaft. The following variables are defined in this connector:

phi: Absolute rotation angle of the shaft flange in [rad].
tau: Cut-torque in the shaft flange in [Nm].

There is a second connector for flanges: Flange_a. The connectors Flange_a and Flange_b are completely identical. There is only a difference in the icons, in order to easier identify a flange variable in a diagram. For a discussion on the actual direction of the cut-torque tau and of the rotation angle, see section Sign Conventions in the user's guide of Rotational.

If needed, the absolute angular velocity w and the absolute angular acceleration a of the flange can be determined by differentiation of the flange angle phi:

w = der(phi);
a = der(w);

Extends from Flange (One-dimensional rotational flange).

Contents

Modelica.Mechanics.Rotational.Interfaces.Support

Support/housing flange of a one-dimensional rotational shaft

Information

This is a connector for 1-dim. rotational mechanical systems and models which represents a support or housing of a shaft. The following variables are defined in this connector:

phi: Absolute rotation angle of the support/housing in [rad].
tau: Reaction torque in the support/housing in [Nm].

The support connector is usually defined as conditional connector. It is most convenient to utilize it

• For models to be build graphically (i.e., the model is build up by drag-and-drop from elementary components):
  PartialOneFlangeAndSupport,
  PartialTwoFlangesAndSupport.
   
• For models to be build textually (i.e., elementary models):
  PartialElementaryOneFlangeAndSupport,
  PartialElementaryTwoFlangesAndSupport,
  PartialElementaryRotationalToTranslational.

Extends from Flange (One-dimensional rotational flange).

Contents

Modelica.Mechanics.Rotational.Interfaces.InternalSupport

Adapter model to utilize conditional support connector

Information

This is an adapter model to utilize a conditional support connector in a component. It could be applied to both textually (equations based) and graphically defined components:

• If useSupport = true, this flange has to be connected to the conditional support connector.
• If useSupport = false, this flange has to be connected to the conditional fixed model.

Variable tau is defined as input. It must be provided as a modifier and computed via a torque balance when using this model in textually defined components. This approach of internal support is utilized, e.g., via the following partial models:

• PartialOneFlangeAndSupport,
• PartialTwoFlangesAndSupport,
• PartialElementaryRotationalToTranslational.

Note, the support angle can always be accessed as internalSupport.phi, and the support torque can always be accessed as internalSupport.tau.

Connectors

Modelica.Mechanics.Rotational.Interfaces.PartialTwoFlanges

Partial model for a component with two rotational 1-dim. shaft flanges

Information

This is a 1-dim. rotational component with two flanges. It is used e.g., to build up parts of a drive train consisting of several components.

Connectors

Modelica.Mechanics.Rotational.Interfaces.PartialOneFlangeAndSupport

Partial model for a component with one rotational 1-dim. shaft flange and a support used for graphical modeling, i.e., the model is build up by drag-and-drop from elementary components

Information

This is a 1-dim. rotational component with one flange and a support/housing. It is used e.g., to build up parts of a drive train graphically consisting of several components.

If useSupport=true, the support connector is conditionally enabled and needs to be connected.
If useSupport=false, the support connector is conditionally disabled and instead the component is internally fixed to ground.

Parameters

Connectors

Modelica.Mechanics.Rotational.Interfaces.PartialTwoFlangesAndSupport

Partial model for a component with two rotational 1-dim. shaft flanges and a support used for graphical modeling, i.e., the model is build up by drag-and-drop from elementary components

Information

This is a 1-dim. rotational component with two flanges and a support/housing. It is used e.g., to build up parts of a drive train graphically consisting of several components.

If useSupport=true, the support connector is conditionally enabled and needs to be connected.
If useSupport=false, the support connector is conditionally disabled and instead the component is internally fixed to ground.

Parameters

Connectors

Modelica.Mechanics.Rotational.Interfaces.PartialCompliant

Partial model for the compliant connection of two rotational 1-dim. shaft flanges

Information

This is a 1-dim. rotational component with a compliant connection of two rotational 1-dim. flanges where inertial effects between the two flanges are neglected. The basic assumption is that the cut-torques of the two flanges sum-up to zero, i.e., they have the same absolute value but opposite sign: flange_a.tau + flange_b.tau = 0. This base class is used to built up force elements such as springs, dampers, friction.

Connectors

Modelica.Mechanics.Rotational.Interfaces.PartialCompliantWithRelativeStates

Partial model for the compliant connection of two rotational 1-dim. shaft flanges where the relative angle and speed are used as preferred states

Information

This is a 1-dim. rotational component with a compliant connection of two rotational 1-dim. flanges where inertial effects between the two flanges are neglected. The basic assumption is that the cut-torques of the two flanges sum-up to zero, i.e., they have the same absolute value but opposite sign: flange_a.tau + flange_b.tau = 0. This base class is used to built up force elements such as springs, dampers, friction.

The relative angle and the relative speed are defined as preferred states. The reason is that for some drive trains, such as drive trains in vehicles, the absolute angle is quickly increasing during operation. Numerically, it is better to use relative angles between drive train components because they remain in a limited size. For this reason, StateSelect.prefer is set for the relative angle of this component.

In order to improve the numerics, a nominal value for the relative angle can be provided via parameter phi_nominal in the Advanced menu. The default is 1e-4 rad since relative angles are usually in this order and the step size control of an integrator would be practically switched off, if a default of 1 rad would be used. This nominal value might also be computed from other values, such as "phi_nominal = tau_nominal / c" for a rotational spring, if tau_nominal and c are more meaningful for the user.

See also the discussion State Selection in the User's Guide of the Rotational library.

Parameters

Connectors

Modelica.Mechanics.Rotational.Interfaces.PartialElementaryOneFlangeAndSupport2

Partial model for a component with one rotational 1-dim. shaft flange and a support used for textual modeling, i.e., for elementary models

Information

This is a 1-dim. rotational component with one flange and a support/housing. It is used to build up elementary components of a drive train with equations in the text layer.

If useSupport=true, the support connector is conditionally enabled and needs to be connected.
If useSupport=false, the support connector is conditionally disabled and instead the component is internally fixed to ground.

Parameters

Connectors

Modelica.Mechanics.Rotational.Interfaces.PartialElementaryTwoFlangesAndSupport2

Partial model for a component with two rotational 1-dim. shaft flanges and a support used for textual modeling, i.e., for elementary models

Information

This is a 1-dim. rotational component with two flanges and a support/housing. It is used to build up elementary components of a drive train with equations in the text layer.

If useSupport=true, the support connector is conditionally enabled and needs to be connected.
If useSupport=false, the support connector is conditionally disabled and instead the component is internally fixed to ground.

Parameters

Connectors

Modelica.Mechanics.Rotational.Interfaces.PartialElementaryRotationalToTranslational

Partial model to transform rotational into translational motion

Information

This is a 1-dim. rotational component with

• one rotational flange,
• one rotational support/housing,
• one translational flange, and
• one translational support/housing

This model is used to build up elementary components of a drive train transforming rotational into translational motion with equations in the text layer.

If useSupportR=true, the rotational support connector is conditionally enabled and needs to be connected.
If useSupportR=false, the rotational support connector is conditionally disabled and instead the rotational part is internally fixed to ground.
If useSupportT=true, the translational support connector is conditionally enabled and needs to be connected.
If useSupportT=false, the translational support connector is conditionally disabled and instead the translational part is internally fixed to ground.

Parameters

Connectors

Modelica.Mechanics.Rotational.Interfaces.PartialTorque

Partial model of a torque acting at the flange (accelerates the flange)

Information

Partial model of torque that accelerates the flange.

If useSupport=true, the support connector is conditionally enabled and needs to be connected.
If useSupport=false, the support connector is conditionally disabled and instead the component is internally fixed to ground.

Extends from Modelica.Mechanics.Rotational.Interfaces.PartialElementaryOneFlangeAndSupport2 (Partial model for a component with one rotational 1-dim. shaft flange and a support used for textual modeling, i.e., for elementary models).

Parameters

Connectors

Modelica.Mechanics.Rotational.Interfaces.PartialAbsoluteSensor

Partial model to measure a single absolute flange variable

Information

This is a partial model of a 1-dim. rotational component with one flange of a shaft in order to measure an absolute kinematic quantity in the flange and to provide the measured signal as output signal for further processing with the blocks of package Modelica.Blocks.

Extends from Modelica.Icons.RoundSensor (Icon representing a round measurement device).

Connectors

Modelica.Mechanics.Rotational.Interfaces.PartialRelativeSensor

Partial model to measure a single relative variable between two flanges

Information

This is a partial model for 1-dim. rotational components with two rigidly connected flanges in order to measure relative kinematic quantities between the two flanges or the cut-torque in the flange and to provide the measured signal as output signal for further processing with the blocks of package Modelica.Blocks.

Extends from Modelica.Icons.RoundSensor (Icon representing a round measurement device).

Connectors

Modelica.Mechanics.Rotational.Interfaces.PartialFriction

Partial model of Coulomb friction elements

Information

Basic model for Coulomb friction that models the stuck phase in a reliable way.

This procedure is implemented in a "clean" way by state events and leads to a mixed continuous/discrete systems of equations if friction elements are dynamically coupled which have to be solved by appropriate numerical methods. The method is described in (see also a short sketch in UsersGuide.ModelingOfFriction):

Otter M., Elmqvist H., and Mattsson S.E. (1999):

Hybrid Modeling in Modelica based on the Synchronous Data Flow Principle. CACSD'99, Aug. 22.-26, Hawaii.

Parameters