Application module: Derived shape element | ISO/TS 10303-1130:2018-11(E) © ISO |
This clause specifies the information requirements for the Derived shape element application module. The information requirements are specified as the Application Reference Model (ARM) of this application module.
NOTE 1 A graphical representation of the information requirements is given in Annex C.
NOTE 2 The mapping specification is specified in 5.1. It shows how the information requirements are met by using common resources and constructs defined or imported in the MIM schema of this application module.
This clause defines the information requirements to which implementations shall conform using the EXPRESS language as defined in ISO 10303-11. The following begins the Derived_shape_element_arm schema and identifies the necessary external references.
EXPRESS specification:
*)
SCHEMA Derived_shape_element_arm;
(*
The following EXPRESS interface statements specify the elements imported from the ARMs of other application modules.
EXPRESS specification:
*)
USE FROM
Construction_geometry_arm;
--
ISO/TS 10303-1131
USE FROM
Shape_property_assignment_arm;
--
ISO/TS 10303-1032
USE FROM
Value_with_unit_arm;
--
ISO/TS 10303-1054
(*
NOTE 1 The schemas referenced above are specified in the following part of ISO 10303:
Construction_geometry_arm ISO/TS 10303-1131 Shape_property_assignment_arm ISO/TS 10303-1032 Value_with_unit_arm ISO/TS 10303-1054
NOTE 2 See Annex C, Figures C.1and C.2 for a graphical representation of this schema.
This subclause specifies the ARM type for this application module. The ARM type and definition is specified below.
The dse_shape_model type is an extension of the shape_model type. It adds the data type Constructive_geometry to the list of alternate data types.
EXPRESS specification:
*)
TYPE
dse_shape_model =
SELECT
BASED_ON
shape_model
WITH
(Constructive_geometry);
END_TYPE;
(*
This subclause specifies the ARM entities for this module. Each ARM application entity is an atomic element that embodies a unique application concept and contains attributes specifying the data elements of the entity. The ARM entities and definitions are specified below.
EXPRESS specification:
*)
ENTITY Apex
SUBTYPE OF (Derived_shape_element);
END_ENTITY;
(*
NOTE The precise interpretation of a Centre_axis is context dependent. That is, the distinction is not made between an axis of a feature and a derived median line of a feature as defined in 1.3 of ASME Y14.5M.
EXAMPLE A Position_tolerance and a Straightness_tolerance may be applied to the same Centre_axis of a cylindrical Shape_element.
EXPRESS specification:
*)
ENTITY Centre_axis
SUBTYPE OF (Centre_of_symmetry);
WHERE
WR1: NOT EXISTS(SELF\Shape_element.description);
END_ENTITY;
(*
Formal propositions:
WR1: The description shall not be specified.
Informal propositions:
IP1: The form of the Shape_elements from which the Centre_axis is derived shall be consistent with the form of shape elements from which a centre axis can be derived.
EXPRESS specification:
*)
ENTITY Centre_of_symmetry
SUPERTYPE OF (ONEOF (Centre_axis,
Centre_plane,
Centre_point,
Median_curve,
Median_surface))
SUBTYPE OF (Derived_shape_element);
END_ENTITY;
(*
EXAMPLE A Flatness_tolerance may be applied to the Centre_plane of two opposing planar Shape_elements.
EXPRESS specification:
*)
ENTITY Centre_plane
SUBTYPE OF (Centre_of_symmetry);
WHERE
WR1: NOT EXISTS(SELF\Shape_element.description);
END_ENTITY;
(*
Formal propositions:
WR1: The description shall not be specified.
Informal propositions:
IP1: The form of the Shape_elements from which the Centre_plane is derived shall be consistent with the form of shape elements from which a centre plane can be derived.
EXPRESS specification:
*)
ENTITY Centre_point
SUBTYPE OF (Centre_of_symmetry);
WHERE
WR1: NOT EXISTS(SELF\Shape_element.description);
END_ENTITY;
(*
Formal propositions:
WR1: The description shall not be populated.
Informal propositions:
IP1: The form of the Shape_elements from which the Centre_point is derived shall be consistent with the form of shape elements from which a centre point can be derived.
EXAMPLE The centre plane of an ideal slot is an example of a Derived_shape_element, that is derived from a symmetrical feature of the shape of a part. Its shape is uniquely specified without further geometric description.
Each Derived_shape_element is either an Apex, a Centre_of_symmetry, a Geometric_contact, an Extension, a Geometric_intersection, a Geometric_alignment, a Parallel_offset, a Perpendicular_to, or a Tangent.EXPRESS specification:
*)
ENTITY Derived_shape_element
ABSTRACT SUPERTYPE
OF (ONEOF (Apex,
Centre_of_symmetry,
Geometric_contact,
Extension,
Geometric_intersection,
Geometric_alignment,
Parallel_offset,
Perpendicular_to,
Tangent))
SUBTYPE OF (Shape_element);
derived_from : SET[1:?] OF Shape_element;
END_ENTITY;
(*
Attribute definitions:
derived_from: the set of instances of Shape_element from which the Derived_shape_element is derived.
NOTE Cardinality of this set depends on the kind of derivation.
EXPRESS specification:
*)
ENTITY Extension
SUBTYPE OF (Derived_shape_element);
SELF\Derived_shape_element.derived_from : SET[1:1] OF Shape_element;
END_ENTITY;
(*
Attribute definitions:
derived_from: an attribute inherited from the Derived_shape_element shall be redeclared as the Shape_element for the Extension. There shall exist exactly one Shape_element for the Extension.
EXPRESS specification:
*)
ENTITY Geometric_alignment
SUBTYPE OF (Derived_shape_element);
SELF\Derived_shape_element.derived_from : SET[2:?] OF Shape_element;
END_ENTITY;
(*
Attribute definitions:
derived_from: an attribute inherited from the Derived_shape_element shall be redeclared as the Shape_element for the Geometric_alignment. There shall exist two or more Shape_elements for the Geometric_alignment.
EXPRESS specification:
*)
ENTITY Geometric_contact
SUBTYPE OF (Derived_shape_element);
SELF\Derived_shape_element.derived_from : SET[2:2] OF Shape_element;
END_ENTITY;
(*
Attribute definitions:
derived_from: an attribute inherited from the Derived_shape_element shall be redeclared as the Shape_element for the Geometric_contact. There shall exist exactly two Shape_elements for the Geometric_contact.
NOTE Since a Geometric_intersection is a derived shape, the use of intersection here is independent of any specific representation.
EXAMPLE A Geometric_intersection is established by the intersection of two planar extensions from the adjacent sides of the block.
EXPRESS specification:
*)
ENTITY Geometric_intersection
SUBTYPE OF (Derived_shape_element);
SELF\Derived_shape_element.derived_from : SET[2:?] OF Shape_element;
END_ENTITY;
(*
Attribute definitions:
derived_from: an attribute inherited from the Derived_shape_element shall be redeclared as the Shape_element for the Geometric_intersection. There shall exist two or more Shape_elements for the Geometric_intersection.
EXPRESS specification:
*)
ENTITY Median_curve
SUBTYPE OF (Centre_of_symmetry);
WHERE
WR1: NOT EXISTS(SELF\Shape_element.description);
END_ENTITY;
(*
Formal propositions:
WR1: The description shall not be specified.
Informal propositions:
IP1: The form of the Shape_elements from which the Median_curve is derived shall be consistent with the form of shape elements from which a median curve can be derived.
EXPRESS specification:
*)
ENTITY Median_surface
SUBTYPE OF (Centre_of_symmetry);
WHERE
WR1: NOT EXISTS(SELF\Shape_element.description);
END_ENTITY;
(*
Formal propositions:
WR1: The description shall not be specified.
Informal propositions:
IP1: The form of the Shape_elements from which the Median_surface is derived shall be consistent with the form of shape elements from which a median surface can be derived.
EXPRESS specification:
*)
ENTITY Offset_shape_element
SUBTYPE OF (Derived_shape_element);
offset : Value_with_unit;
END_ENTITY;
(*
Attribute definitions:
offset: the constant distance between the Offset_shape_element and the shape element instance that is the value of derived_from.
EXPRESS specification:
*)
ENTITY Parallel_offset
SUBTYPE OF (Derived_shape_element);
SELF\Derived_shape_element.derived_from : SET[1:1] OF Shape_element;
END_ENTITY;
(*
Attribute definitions:
derived_from: an attribute inherited from the Derived_shape_element shall be redeclared as the Shape_element for the Parallel_offset. There shall exist exactly one Shape_element for the Parallel_offset.
EXPRESS specification:
*)
ENTITY Perpendicular_to
SUBTYPE OF (Derived_shape_element);
SELF\Derived_shape_element.derived_from : SET[1:1] OF Shape_element;
END_ENTITY;
(*
Attribute definitions:
derived_from: an attribute inherited from the Derived_shape_element shall be redeclared as the Shape_element for the Perpendicular_to. There shall exist exactly one Shape_element for the Perpendicular_to.
EXPRESS specification:
*)
ENTITY Tangent
SUPERTYPE OF (Tangent_plane)
SUBTYPE OF (Derived_shape_element);
SELF\Derived_shape_element.derived_from : SET[1:1] OF Shape_element;
END_ENTITY;
(*
Attribute definitions:
derived_from: an attribute inherited from the Derived_shape_element shall be redeclared as the Shape_element for the Tangent. There shall exist exactly one Shape_element for the Tangent.
EXPRESS specification:
*)
ENTITY Tangent_plane
SUBTYPE OF (Tangent);
WHERE
WR1: NOT EXISTS(SELF\Shape_element.description);
END_ENTITY;
(*
Formal propositions:
WR1: The description shall not be populated.
*)
END_SCHEMA; -- Derived_shape_element_arm
(*
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