Mechanical Systems Design Database Design Import

V5 Data Type	3DEXPERIENCE Content Type	Import Result
Mechanisms	Mechanisms	Fully Imported Mechanism and submechanism are imported as mechanism representation. See Imported submechanism.
Commands	Commands	Fully Imported
Joints	Converted as typed engineering connection.	Partially Imported A joint is imported in an engineering connections using the same name. Rigid joint is imported as rigid engineering connection made of Fix Together: Fix Together with N instances is converted as a Fix Together constraint in a single Rigid engineering connection. Fix Together of Fix together is converted as Rigid engineering connections of Fix Together. Prismatic joint is imported as prismatic engineering connection. Revolute joint is imported as revolute engineering connection. Spherical joint is imported as spherical engineering connection. Cylindrical joint is imported as cylindrical engineering connection Planar joint is imported as planar engineering connection. U joint is imported as universal engineering connection. Point Curve joint is imported as point curve engineering connection. The imported point curve engineering connection is always based on a curvilinear constraint, regardless of the constraint types that were used to define the V5 joint. Point Surface joint is imported as point surface engineering connection. Roll Curve joint is imported as roll curve engineering connection. Slide Curve joint is imported as slide curve engineering connection. Gear joint is imported as gear engineering connection and two revolute engineering connections; the gear connection couples the two revolute connections. Rack joint is imported as rack engineering connection, prismatic engineering connection, and revolute engineering connection; the rack connection couples the prismatic and revolute connections. Cable joint is imported as cable engineering connection and two prismatic engineering connections; the cable connection couples the two prismatic connections. Screw joint is imported as screw engineering connection. CV joint is imported as two universal engineering connections. Axis-Based joint is imported as appropriate engineering connection and an axis system.

Considerations

The following considerations are to be taken into account:

Commands

V5 commands are imported as controlled constraints in the 3DEXPERIENCE engineering connections; commands based on these controlled constraints are created in the 3DEXPERIENCE mechanism representation. These controlled constraints rely on a geometry, computed on the fly, based on other geometries of the engineering connection.

Import of Mechanisms

CATIA V5 and 3DEXPERIENCE mechanisms have a different structure. For more information, see Structure Diagrams - 3DEXPERIENCE vs V5. As a consequence, mechanisms that work in V5 may behave differently after being imported into 3DEXPERIENCE. The sections below describe some specific situations, and provide recommendations. Complete the following general steps before attempting to simulate a V5 mechanism in 3DEXPERIENCE:

• Review and clean the mechanism in V5 using the CATDUA utility.
• Update the assembly.
• Update and save the cleaned mechanism in V5.
• Import the V5 mechanism into 3DEXPERIENCE.
• Launch the Update process.

For a V5 U joint based on two lines (non-associative) or two axis-systems (associative), two axis systems are created in the engineering connection to replace the original geometries used in the V5 joint. But if there is an equivalent set of V5 constraints (coincidence and angle) in V6, axis systems are not generated, which makes the V6 U joint associative and geometrical modifications are supported.

Import Mechanisms in Asynchronous Mode

Asynchronous migration allows you to update a previously imported mechanism in 3DEXPERIENCE with changes that were made in V5. For details about using asynchronous migration, see File Coexistence and Migration User's Guide.

The following modifications to a V5 mechanism can be propagated to an existing 3DEXPERIENCE mechanism using asynchronous migration:

• Create/delete a mechanism
• Simulate a mechanism
• Create/delete a joint
• Modify the ratio of a joint
• Modify the limits of a joint
• Create/delete/rename a command
• Delete the Fixed Part.

Warning: Any modifications to the mechanism that are made in 3DEXPERIENCE are lost when you perform an asynchronous migration; the updated mechanism is based entirely on the contents of the current V5 mechanism.

The name of the imported mechanism is always based on the mechanism name at the time of the original import. If you rename the mechanism in V5 or 3DEXPERIENCE, the original name is restored on the 3DEXPERIENCE mechanism when you perform an asynchronous migration.

Broken Joints

If the supporting constraints or geometries have been deleted from a V5 joint, the joint will be "broken" when it is imported into 3DEXPERIENCE.

FBDI tool attempts to repair broken joints during the import.

The repair process may create new constraints (for deleted constraints) or new axis systems (for missing geometry) in the 3DEXPERIENCE model.

The following types of joints can be repaired:

• Rigid
• Prismatic
• Revolute
• Spherical
• Cylindrical
• Planar
• Fixed
• Compound (gear, rack, and, cable).

The repair process may fail in the following situations:

• The geometry of the mechanism is not imported into 3DEXPERIENCE
• The underlying geometry for the V5 joint constraints is not appropriate for the associated engineering connections, or
• The initial value of the V5 joint command is outside of the 3DEXPERIENCE controlled constraint limits
• A sub-joint that belongs to a V5 compound joint (gear, rack, or cable) has been deleted.

If the repair process fails, the 3DEXPERIENCE mechanism is incomplete and cannot be simulated.

The Engineering Connection options for the Assembly Design app determine how broken joints are handled during import: they can be imported and deactivated, imported and kept active, or not imported. See Me > Preferences > Mechanical > Assembly Design.

If broken joints are imported into your 3DEXPERIENCE mechanism, they must be repaired manually. Performing a PLM Update (after activating the broken joints, for example) can provide diagnostic and error messages concerning the problems with the broken joints.

Important: If you delete the V5 assembly constraints of an up-to-date V5 Kinematics mechanism, the V5 Joints remain valid from a pure kinematics point of view. After the FBDI, the V5 joints with or without V5 constraints are imported as the same engineering connections despite the warning message raised in the FBDI status report. This behavior also applies to the V5 fix of the mechanism with or without the V5 fix assembly constraint.

Import of Joints with Driven Kinematic Commands

If you import a V5 kinematic joint driven by a command in the 3DEXPERIENCE, no geometry is associated as support for that command.

As a consequence, a new constraint is created for the joint. The constraint supports are computed, based on existing geometries from the model.

This additional constraint is created for the following joint types:

• Revolute
• Prismatic
• Cylindrical
• Screw
• Gear
• Rack
• Cable

Depending on the degrees of freedom of the imported joint, an additional constraint is created and defined.

Joint Degrees of Freedom	Additional Constraint	Mode	Preferences	First Support	Second Support	Third Support
Translation	Offset	Controlled	Above, Same	Computed plane, normal to the first edge.	Computed plane, normal to the second edge.	—
Rotation	Hinge	Controlled	Sector1	Computed plane including the first edge (axis).	Computed plane including the second edge (axis).	Edge (corresponding to the first edge).

Notes:

• In the Engineering Connection Definition dialog box, you can specify the constraint value, lower value, and upper value, but the constraint mode, preferences, and supports are defined by default and cannot be edited.
• Computed supports are not highlighted in the tree or in the 3D area.

Screw Joints - Deleting Constraints

If you import a V5 Screw joint and delete the Hinge constraint, the Coincidence and Offset constraints are automatically deleted.

Limits

If a V5 joint command uses the default value limits (-100 to 100 for length-based commands, -360° to 360° for angle-based commands), those limits are imported and assigned to the controlled constraint in the engineering connection.

If non default limits are defined for a V5 joint command, these limits are imported into the controlled constraint in the engineering connection.

If a V5 mechanism is not updated before the import, it is possible for the nominal value of a command to be outside of the defined command limits. During import, the nominal value is reset in the mechanism to either the maximum limit value (if the nominal value was above the limit range) or the minimum limit value (if the nominal value was below the limit range).

If a V5 mechanism is not updated before the import, it is possible for the nominal value of a command to be outside of the defined command limits. During import, the nominal value is reset in the mechanism to either the maximum limit value (if the nominal value was above the limit range) or minimum limit value (if the nominal value was below the limit range).

In V5, command limits are not enforced during a mechanism simulation. For example, a revolute joint with an upper limit of 360° may continue to rotate past 360° during a simulation. The command limits are enforced during a mechanism simulation. Therefore, a mechanism simulation that appears to work in V5 may not work in because the upper or lower command limits are reached during the simulation. Removing or redefining the command limits in the mechanism typically resolves this problem.

Duplicate Joints

In V5, two mechanism representations within a single product may include identical joint definitions. In the 3DEXPERIENCE, these joints are combined into a single engineering connection at the product level; modifications to this engineering connection are reflected in both mechanism representations.

Similar V5 joints are not combined in 3DEXPERIENCE if any of the following conditions exist:

• The products involved in the joints are different.
• The joint types are different.
• The number or types of coincidence constraints in the joint definitions are not identical.
• The support geometries in the joint definitions are not identical.

Duplicate joints often appear when compound connections are "chained" together. For example, a mechanism involving three sequentially enmeshed gears typically requires the definition of two gear connections: one to link the first gear to the second gear, and another to link the second gear to the third gear. In V5, a unique revolute joint must be created for use in each gear joint definition, resulting in two identical revolute joints on the second gear. 3DEXPERIENCE does not require unique engineering connections for each compound connection; the same engineering connection can be used in multiple compound connections. When this mechanism is imported from V5 to 3DEXPERIENCE, the duplicate revolute joint is removed and a single revolute connection is used in the definition of both gear engineering connections.

Structure Diagrams - V5 vs 3DEXPERIENCE

In V5, a mechanism consists of joints, commands, and a fixed part; the mechanism joints are distinct from assembly constraints in the associated product. In the 3DEXPERIENCE, both mechanism joints and assembly constraints are derived from common engineering connections in the product .

When importing a V5 product that includes a mechanism, a 3DEXPERIENCE product and associated mechanism representation are created. Joints in the V5 mechanism are defined as engineering connections in the 3DEXPERIENCE product; these engineering connections are also included in the mechanism representation.

V5 commands are imported as controlled constraints in the 3DEXPERIENCE engineering connections; commands based on these controlled constraints are created in the 3DEXPERIENCE mechanism representation. These controlled constraints rely on a geometry, computed on the fly, based on other geometries of the engineering connection.

The left column illustrates V5, the right column 3DEXPERIENCE.

Imported Submechanisms

In V5, it is possible to define a mechanism for a product (Product B), then instance this product within another product (Product A). You can then define another mechanism for Product A based on the geometry and joints in Product B. This second mechanism is called an "imported" mechanism; the original mechanism and the imported mechanism are identical, but they are instanced at different levels in the product structure. In this situation, Product B is flexible (or made flexible at first simulation).

These "imported" mechanisms in the V5 product are supported by file-based design import. In 3DEXPERIENCE, product B remains flexible and the mechanism under Product A assembles the mechanism in product B.

These "imported" mechanisms in the V5 product are supported by file-based design import. In 3DEXPERIENCE, product B remains flexible and the mechanism under Product A assembles the mechanism in product B.

V5 Tree Elements	3DEXPERIENCE Tree Elements
Main Product Subproduct	Main Product Subproduct
Applications	Mechanism
Mechanism Joints	Joints
Joint 1 Joint 2	Connection. 1 Connection. 2
Applications	Mechanism
Imported mechanism	Assembly
Joints	Mechanism Subproduct

Dressup

In CATIA V5, with the dressup function it is possible to attach one or several parts to a given moving part involved in the mechanism. You can then include parts that are not involved in the mechanism in the kinematics simulation. When importing a V5 dressup to 3DEXPERIENCE, rigid engineering connections between the mechanism and the dressup are created. Dressup is defined as rigid engineering connections in the 3DEXPERIENCE product; these engineering connections are included in the mechanism representation.

V5 Tree Elements	3DEXPERIENCE Tree Elements
Product	Product
Applications	Mechanism
Mechanism	Joints
Joints	Connection 1 Connection 2
Joint 1 Joint 2	Dressup
Dressup	Rigid Connection 1 Rigid Connection 2

Important: For more information about FBDI of imported submechanisms and dressups, see the dedicated article in the Knowledge Base.