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StructuralConstraintsPlanar,PinandBallConstraintsLecture

PlanarPinandBallConstraints.mp3Planar, Pin, and Ball Constraints

Planar, pin, and ball, constraints enable you to easily specify

engineering constraints.

Created from:

Fly-out menu Insert drop-down menu

Types:

Planaro Constrains: Off-plane displacement.o Enables: In-plane translation.

Pino Constrains: Radial translation and rotation. Optional: Angular rotation ()

and axial translation (Z).

o Enables: Optional: Angular rotation () and axial translation (Z). Ball:

o Constrains: All translational degrees of freedom.o Enables: All rotational degrees of freedom.

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The Planar, Pin, and Ball Constraints Fly-out MenuLectureNotes

Creating Planar, Pin, and Ball Constraints

When creating planar, pin, and ball constraints you must first select the type ofconstraint from either a fly-out menu on the Mechanica toolbar or directly from theInsert drop-down menu in the main menu.

Planar constraints enable the creation of a constraint that allows full planarmovement, but constrains off-plane displacement. You can select only planarsurfaces for this type of constraint.

Pin constraints enable the creation of a constraint that controls the translationor rotation about the axis of a cylindrical surface in 3D models. The pinconstraint is particularly useful when you need the surface to move in one ormore directions, but be held in place in the remaining directionsfor example, apiston that slides within a cylinder, but stays tight to the inner cylinder wall and

does not rotate. You can select only cylindrical surfaces for this type ofconstraint.Additionally, the pin constraint enables you to specify the Angulardegree of freedom as Free or Fixed, and the Axial degree of freedom as Free orFixed.

Ball constraints enable the creation of a constraint that represents a ball joint inwhich translation is fixed while rotation is free. You can select only sphericalsurfaces for this type of constraint.

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Best Practices

Planar, pin and ball constraints are not valid for Large Deformation Analysis (LDA). If

a model with these constraints is used to create or edit an LDA, Mechanica will display

an error message.

Planar,PinandBallConstraintsDemonstrationPlanarPinandBallConstraints_demo.mp4

Planar,PinandBallConstraintsProcedureProcedure: Planar, Pin, and Ball Constraints

ScenarioIn this exercise you learn how to create pin and ball constraints.

PlanarPinBall linkage.prt

Task 1. Open the Mechanica application and create a pin constraint.

1. Click Applications > Mechanica.

2. Click the fly-out menu next to Planar Constraint in the Mechanica toolbar to

show its contents. Then click Pin Constraint as shown.

3. Select the surface inside the hole as shown.

4. Verify that the angular rotation and axial translation degrees of freedom are set to

Free as shown.

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5. Click OK from the Pin Constraint dialog box to create the constraint.

Task 2. Create a ball constraint, save the model, and erase it from memory.

1. Click the constraint fly-out menu and click Ball Constraint .

2. Select the spherical surface as shown.

3. Click OK from the Ball Constraint dialog box to create the constraint.

4. Return to the Standard Pro/ENGINEER mode by clicking Applications > Standard.

5. Click Save from the main toolbar and click OK to save the model.

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6. Click File > Erase > Current > Yes to erase the model from memory.

This completes the procedure.