Pattern Compliant

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Pattern Compliant

The purpose of PatternCompliant_icon Pattern Compliant routine is to assemble two parts that have multiple sets of pins and holes as the secondary and tertiary locators. Both parts or only one part can be compliant.

 

Specifics of Pattern Compliant:

1.Pattern Compliant can be used for Floating Fastener only and it's set to use the Float-Fit-Fastener option. The Float-Fit-Fastener can be used with no pins at all, pins for some of the hole pairs, or pins for all hole pairs.

2.Align plane is always activated - will translate the object part until it aligns the first object feature to the first target feature in the Pattern's direction (direction can be set with the available Dir. Type options), thus setting the the primary plane of the object part(s).  This way the move controls all six degrees of freedom of the object part(s).

3.Move steps:

3.1. Initially the Float-Fit-Fastener pattern rigid move is used to find out the position of the object holes relative to the target holes. No movement or deformation is applied to the object part. If the pattern move cannot be executed the failed samples will be itemized in the Run Log.

3.2. Next the pattern compliant is applied to clamp or join the object holes to the target holes at the locations calculated with the previous pattern rigid. When this happens the object and/or target parts are fully constrained so the part(s) will stretch and deform during this operation.

4.When executing several pattern compliant moves, during the second pattern compliant move, internal clamp/joint respects the outcome of the first pattern compliant move, but ignores the clamp/joint operations when floating.

5.This move requires a mesh file and a stiffness matrix loaded for the object and target parts (if the target part is compliant).

6.Parts must be constrained with compliant move prior to applying the Pattern Compliant. If the target part is rigid it does not need to be constrained.

 

PatternCompliant

 

Inputs

Select the PatternCompliant_icon Pattern Compliant icon to open the Pattern Compliant Move dialog box.

Name: The move name must be unique to the model.

Description: This is an optional explanation of what the move does.

Help: The Help button is context sensitive; it will open the Help Manual at required topic page.

Check the box to Turn On Smoothing (only to show the deformation graphically).

 

Feature Tab

Object Features: 2 to n object points with corresponding hole diameters.

Target Features: 2 to n target points with corresponding hole diameters.

Pin Features: 0 to n pins with corresponding pin diameters.

 

Direction Tab

Directions: This is the alignment direction for the pairs of holes. The Dir Type can be toggled between Type In, Two Pt, Normal, AssocDir, PickPtDir.

step_24If AssocDir is selected, the floating direction is the direction of the first Target Feature.

step_24If PickPtDir is selected, user can type in the point name, or select editor first then click pt on screen.

 

Options Tab

Conditional Logic: A condition can be added to this move. See Conditional Logic

Open Increment: This is the number used to increase the temporary opening in order to find a solution.

Iter Num: The number of times the move should perform, in order to find a solution.

 

Move Parts Tab

Shows the parts that will be repositioned. Parts are automatically added based on the object points selected in the move.

 

Outputs

Pattern rigid will move the object points to new positions. Then the object points will be clamped or joined to that new positions.

 

Note: If a no-build condition exists, Pattern Move will report the "no builds" during Nominal Build and Assembly.

 

PatternCompliantModelLog

 

Assumptions

The opening between a pair of holes can never be larger than the smallest hole.

The accuracy will only be as good as the 'Open Increment'.

A minimum of two sets of holes is needed for this routine.

The smaller the value used for 'Open Increment', the longer the model may run to find a max opening.

Vector used to define the target surface will default to the vector associated with the first target point.

The nominal object and target surfaces, in the area of the holes, are assumed to be flat and parallel.

'x' number of pins:

o        If x = n, all holes will be treated as floating fasteners

o        If x = 0, the object will be adjusted so that the smallest opening will be as large as possible.

Only holes are used (no slots).

 

Notes:

The purpose of the Pattern move is to model the float when multiple hole-pin pairs are used as locators. Since no single pair acts as a locator, the Pattern move cannot calculate a nominal position. Therefore, this move is not activated in the Nominal Build, as well as the Animate functions.  

Furthermore, the Pattern move does not run through high-low-mean states in the Sensitivity Analysis because it is using conditional logic, i.e., the high and low float magnitude will depend on the effect of other tolerances.  The Sensitivity Analysis will show the relative effects of variation excluding the float from the Pattern move. This exclusion does not invalidate the Sensitivity Results, but the user should be aware that the Pattern move may also be contributing to the measured variation.

See Analysis Comparison & Assumptions.

 

Also See:  

Defining Moves        

Common Parameters