Modelica.Mechanics.Translational.Interfaces

Interfaces for 1-dim. translational mechanical components

Information

This package contains connectors and partial models for 1-dim. translational 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 translational flange
Flange_a	One-dimensional translational flange (left, flange axis directed INTO cut plane)
Flange_b	One-dimensional translational flange (right, flange axis directed OUT OF cut plane)
Support	Support/housing flange of a one-dimensional translational component
InternalSupport	Adapter model to utilize conditional support connector
PartialTwoFlanges	Component with two translational 1D flanges
PartialOneFlangeAndSupport	Partial model for a component with one translational 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 translational 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
PartialRigid	Rigid connection of two translational 1D flanges
PartialCompliant	Compliant connection of two translational 1D flanges
PartialCompliantWithRelativeStates	Base model for the compliant connection of two translational 1-dim. shaft flanges where the relative position and relative velocities are used as states
PartialElementaryOneFlangeAndSupport2	Partial model for a component with one translational 1-dim. shaft flange and a support used for textual modeling, i.e., for elementary models
PartialElementaryTwoFlangesAndSupport2	Partial model for a component with one translational 1-dim. shaft flange and a support used for textual modeling, i.e., for elementary models
PartialElementaryRotationalToTranslational	Partial model to transform rotational into translational motion
PartialForce	Partial model of a force acting at the flange (accelerates the flange)
PartialAbsoluteSensor	Device to measure a single absolute flange variable
PartialRelativeSensor	Device to measure a single relative variable between two flanges
PartialFriction	Base model of Coulomb friction elements

Modelica.Mechanics.Translational.Interfaces.Flange

One-dimensional translational flange

Information

This is a connector for 1D translational 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:

s: Absolute position of the flange in [m]. A positive translation
   means that the flange is translated along the flange axis.
f: Cut-force in direction of the flange axis in [N].

Contents

Modelica.Mechanics.Translational.Interfaces.Flange_a

One-dimensional translational flange (left, flange axis directed INTO cut plane)

Information

This is a connector for 1-dim. translational mechanical systems which represents a mechanical flange. In the cut plane of the flange a unit vector n, called flange axis, is defined which is directed INTO the cut plane, i. e. from left to right. All vectors in the cut plane are resolved with respect to this unit vector. E.g. force f characterizes a vector which is directed in the direction of n with value equal to f. When this flange is connected to other 1D translational flanges, this means that the axes vectors of the connected flanges are identical.

The following variables are transported through this connector:

s: Absolute position of the flange in [m]. A positive translation
   means that the flange is translated along the flange axis.
f: Cut-force in direction of the flange axis in [N].

Extends from Flange (One-dimensional translational flange).

Contents

Modelica.Mechanics.Translational.Interfaces.Flange_b

One-dimensional translational flange (right, flange axis directed OUT OF cut plane)

Information

This is a connector for 1-dim. translational mechanical systems which represents a mechanical flange. In the cut plane of the flange a unit vector n, called flange axis, is defined which is directed OUT OF the cut plane. All vectors in the cut plane are resolved with respect to this unit vector. E.g. force f characterizes a vector which is directed in the direction of n with value equal to f. When this flange is connected to other 1D translational flanges, this means that the axes vectors of the connected flanges are identical.

The following variables are transported through this connector:

s: Absolute position of the flange in [m]. A positive translation
   means that the flange is translated along the flange axis.
f: Cut-force in direction of the flange axis in [N].

Extends from Flange (One-dimensional translational flange).

Contents

Modelica.Mechanics.Translational.Interfaces.Support

Support/housing flange of a one-dimensional translational component

Information

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

s: Absolute position of the support/housing in [m].
f: Reaction force in the support/housing in [N].

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 translational flange).

Contents

Modelica.Mechanics.Translational.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 f is defined as input. It must be provided as a modifier and computed via a force 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 position can always be accessed as internalSupport.s, and the support force can always be accessed as internalSupport.f.

Connectors

Modelica.Mechanics.Translational.Interfaces.PartialTwoFlanges

Component with two translational 1D flanges

Information

This is a 1D translational component with two flanges. It is used e.g., to built up parts of a drive train consisting of several base components.

Connectors

Modelica.Mechanics.Translational.Interfaces.PartialOneFlangeAndSupport

Partial model for a component with one translational 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. translational 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.Translational.Interfaces.PartialTwoFlangesAndSupport

Partial model for a component with two translational 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. translational 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.

Extends from Translational.Interfaces.PartialTwoFlanges (Component with two translational 1D flanges).

Parameters

Connectors

Modelica.Mechanics.Translational.Interfaces.PartialRigid

Rigid connection of two translational 1D flanges

Information

This is a 1-dim. translational component with two rigidly connected flanges. The fixed distance between the left and the right flange is defined by parameter "L". The forces at the right and left flange can be different. It is used e.g., to built up sliding masses.

Extends from Translational.Interfaces.PartialTwoFlanges (Component with two translational 1D flanges).

Parameters

Connectors

Modelica.Mechanics.Translational.Interfaces.PartialCompliant

Compliant connection of two translational 1D flanges

Information

This is a 1D translational component with a compliant connection of two translational 1D flanges where inertial effects between the two flanges are not included. The absolute value of the force at the left and the right flange is the same. It is used to built up springs, dampers etc.

Extends from Translational.Interfaces.PartialTwoFlanges (Component with two translational 1D flanges).

Connectors

Modelica.Mechanics.Translational.Interfaces.PartialCompliantWithRelativeStates

Base model for the compliant connection of two translational 1-dim. shaft flanges where the relative position and relative velocities are used as states

Information

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

The difference to base class "PartialCompliant" is that the relative distance and the relative velocity are defined as preferred states. The reason is that for a large class of drive trains, the absolute position is quickly increasing during operation. Numerically, it is better to use relative distances between drive train components because they remain in a limited size. For this reason, StateSelect.prefer is set for the relative distance of this component.

In order to improve the numerics, a nominal value for the relative distance should be set, since drive train distances are in a small order and then step size control of the integrator is practically switched off for such a variable. A default nominal value of s_nominal = 1e-4 is defined. This nominal value might also be computed from other values, such as "s_nominal = f_nominal / c" for a spring, if f_nominal and c have more meaningful values for the user.

Extends from Translational.Interfaces.PartialTwoFlanges (Component with two translational 1D flanges).

Parameters

Connectors

Modelica.Mechanics.Translational.Interfaces.PartialElementaryOneFlangeAndSupport2

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

Information

This is a 1-dim. translational 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.Translational.Interfaces.PartialElementaryTwoFlangesAndSupport2

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

Information

This is a 1-dim. translational component with two flanges and an additional support. It is used e.g., to build up elementary ideal gear components. The component contains the force balance, i.e., the sum of the forces of the connectors is zero (therefore, components that are based on PartialGear cannot have a mass). The support connector needs to be connected to avoid the unphysical behavior that the support force is required to be zero (= the default value, if the connector is not connected).

Extends from Translational.Interfaces.PartialTwoFlanges (Component with two translational 1D flanges).

Parameters

Connectors

Modelica.Mechanics.Translational.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.

Extends from Modelica.Mechanics.Rotational.Interfaces.PartialElementaryRotationalToTranslational (Partial model to transform rotational into translational motion).

Parameters

Connectors

Modelica.Mechanics.Translational.Interfaces.PartialForce

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

Information

Partial model of force 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 PartialElementaryOneFlangeAndSupport2 (Partial model for a component with one translational 1-dim. shaft flange and a support used for textual modeling, i.e., for elementary models).

Parameters

Connectors

Modelica.Mechanics.Translational.Interfaces.PartialAbsoluteSensor

Device to measure a single absolute flange variable

Information

This is the superclass of a 1D translational component with one flange and one output signal 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 Modelica.Blocks blocks.

Extends from Modelica.Icons.RectangularSensor (Icon representing a linear measurement device).

Connectors

Modelica.Mechanics.Translational.Interfaces.PartialRelativeSensor

Device to measure a single relative variable between two flanges

Information

This is a superclass for 1D translational components with two rigidly connected flanges and one output signal in order to measure relative kinematic quantities between the two flanges or the cut-force in the flange and to provide the measured signal as output signal for further processing with the Modelica.Blocks blocks.

Extends from Modelica.Icons.RectangularSensor (Icon representing a linear measurement device), Translational.Interfaces.PartialTwoFlanges (Component with two translational 1D flanges).

Connectors

Modelica.Mechanics.Translational.Interfaces.PartialFriction

Base 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