Modelica.Mechanics.Rotational.Interfaces

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.

Package Content

Name	Description
Flange_a	1-dim. rotational flange of a shaft (filled square icon)
Flange_b	1-dim. rotational flange of a shaft (non-filled square icon)
Support	Support/housing of a 1-dim. 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
PartialElementaryOneFlangeAndSupport	Obsolete partial model. Use PartialElementaryOneFlangeAndSupport2.
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
PartialElementaryTwoFlangesAndSupport	Obsolete partial model. Use PartialElementaryTwoFlangesAndSupport2.
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_a

Information

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

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)

Contents

Name	Description
phi	Absolute rotation angle of flange [rad]
tau	Cut torque in the flange [N.m]

Modelica.Mechanics.Rotational.Interfaces.Flange_b

Information

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

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)

Contents

Name	Description
phi	Absolute rotation angle of flange [rad]
tau	Cut torque in the flange [N.m]

Modelica.Mechanics.Rotational.Interfaces.Support

Information

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

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.

Contents

Name	Description
phi	Absolute rotation angle of the support/housing [rad]
tau	Reaction torque in the support/housing [N.m]

Modelica.Mechanics.Rotational.Interfaces.InternalSupport

Information

This is an adapter model to utilize a conditional support connector in an elementary component, i.e., where the component equations are defined textually:

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

Variable tau is defined as input and must be provided when using this component as a modifier (computed via a torque balance in the model where InternalSupport is used). Usually, model InternalSupport is utilized via the partial models:

PartialElementaryOneFlangeAndSupport,
PartialElementaryTwoFlangesAndSupport,
PartialElementaryRotationalToTranslational.

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

Connectors

Name	Description
flange	Internal support flange (must be connected to the conditional support connector for useSupport=true and to conditional fixed model for useSupport=false)

Modelica.Mechanics.Rotational.Interfaces.PartialTwoFlanges

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

Name	Description
flange_a	Flange of left shaft
flange_b	Flange of right shaft

Modelica.Mechanics.Rotational.Interfaces.PartialOneFlangeAndSupport

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

Name	Description
useSupport	= true, if support flange enabled, otherwise implicitly grounded

Connectors

Name	Description
flange	Flange of shaft
support	Support/housing of component

Modelica.Mechanics.Rotational.Interfaces.PartialTwoFlangesAndSupport

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

Name	Description
useSupport	= true, if support flange enabled, otherwise implicitly grounded

Connectors

Name	Description
flange_a	Flange of left shaft
flange_b	Flange of right shaft
support	Support/housing of component

Modelica.Mechanics.Rotational.Interfaces.PartialCompliant

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

Name	Description
flange_a	Left flange of compliant 1-dim. rotational component
flange_b	Right flange of compliant 1-dim. rotational component

Modelica.Mechanics.Rotational.Interfaces.PartialCompliantWithRelativeStates

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

Name	Description
Advanced
phi_nominal	Nominal value of phi_rel (used for scaling) [rad]
stateSelect	Priority to use phi_rel and w_rel as states

Connectors

Name	Description
flange_a	Left flange of compliant 1-dim. rotational component
flange_b	Right flange of compliant 1-dim. rotational component

Modelica.Mechanics.Rotational.Interfaces.PartialElementaryOneFlangeAndSupport

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

Name	Description
useSupport	= true, if support flange enabled, otherwise implicitly grounded

Connectors

Name	Description
flange	Flange of shaft
support	Support/housing of component

Modelica.Mechanics.Rotational.Interfaces.PartialElementaryOneFlangeAndSupport2

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

Name	Description
useSupport	= true, if support flange enabled, otherwise implicitly grounded

Connectors

Name	Description
flange	Flange of shaft
support	Support/housing of component

Modelica.Mechanics.Rotational.Interfaces.PartialElementaryTwoFlangesAndSupport

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

Name	Description
useSupport	= true, if support flange enabled, otherwise implicitly grounded

Connectors

Name	Description
flange_a	Flange of left shaft
flange_b	Flange of right shaft
support	Support/housing of component

Modelica.Mechanics.Rotational.Interfaces.PartialElementaryTwoFlangesAndSupport2

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

Name	Description
useSupport	= true, if support flange enabled, otherwise implicitly grounded

Connectors

Name	Description
flange_a	Flange of left shaft
flange_b	Flange of right shaft
support	Support/housing of component

Modelica.Mechanics.Rotational.Interfaces.PartialElementaryRotationalToTranslational

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

Name	Description
useSupportR	= true, if rotational support flange enabled, otherwise implicitly grounded
useSupportT	= true, if translational support flange enabled, otherwise implicitly grounded

Connectors

Name	Description
flangeR	Flange of rotational shaft
flangeT	Flange of translational rod
supportR	Rotational support/housing of component
supportT	Translational support/housing of component

Modelica.Mechanics.Rotational.Interfaces.PartialTorque

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.

Parameters

Name	Description
useSupport	= true, if support flange enabled, otherwise implicitly grounded

Connectors

Name	Description
flange	Flange of shaft
support	Support/housing of component

Modelica.Mechanics.Rotational.Interfaces.PartialAbsoluteSensor

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.

Connectors

Name	Description
flange	Flange of shaft from which sensor information shall be measured

Modelica.Mechanics.Rotational.Interfaces.PartialRelativeSensor

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.

Connectors

Name	Description
flange_a	Left flange of shaft
flange_b	Right flange of shaft

Modelica.Mechanics.Rotational.Interfaces.PartialFriction

Information

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

Parameters

Name	Description
Advanced
w_small	Relative angular velocity near to zero if jumps due to a reinit(..) of the velocity can occur (set to low value only if such impulses can occur) [rad/s]