You will learn how to:

Define contact between surfaces.

Set up and solve two different solution subcases

Simulation

This activity analyzes a pulley assembly. There is a steel shaft and nylon pulley that is press-fitted onto the shaft. Open Look in:wheel_shaft_assy

Files of type Part Files (*.prt)

File namewheel_shaft_assy.prt

OK

Start Advanced Simulation

Reset the dialog box settings

The options you select in NX dialog boxes are preserved for the next time you open the same dialog box within an NX session. To ensure that the dialog boxes are in the expected initial state for each step-by-step activity, you should restore the default settings. Preferences User Interface Reset Dialog Box Settings

OK

Create a FEM file

Simulation Navigator Simulation File View

wheel_shaft_assy New FEM Simulation

NX Nastran Fem Millimeters

Namewheel_fem1.fem

Folderyour part file folder name

OKNew Part File dialog box

SolverNX NASTRAN

Analysis TypeStructural

OK New FEM dialog box

Note:In the Simulation Navigator, notice that there are two polygon bodies. Save (Standard toolbar)

Mesh the part

Simulation Navigator wheel_fem1 New Mesh3DTetrahedral TypeCTETRA(10)

Automatic Element Size Apply

TypeCTETRA(10)

Automatic Element Size OK

Change pulley mesh display color

Simulation Navigator 3D Collectors (expand) Solid(2) Mesh Collector Display Properties Color swatch Light Hard Green Note:Or select a similar color. OK

Assign material properties

Retrieve Nylon and Steel from the materials database and assign them to the shaft and pulley.Assign Steel to the shaft.Simulation Navigator 3D Collectors (expand) Solid(1)Edit Modify Selected (Name) Choose material (Material) Materials

Steel

OKall dialog boxes

Assign Nylon to the pulley.Simulation Navigator 3D Collectors (expand) Solid(2) Edit Modify Selected (Name) Choose material (Material) Materials

Nylon

OKall dialog boxes

Create the Simulation file

Up to this point, you have been working in the FEM file. You need to create the Simulation file to define contact, constraints, and the solution. When you define the solution, you will also set some parameters required for contact.Simulation Navigator Simulation File View

wheel_fem1 New Simulation Simulation

NX Nastran Sim Millimeters

Namewheel_sim1.sim

Folderyour part file folder name

OK New Part File dialog box

OK New Simulation dialog box

SESTATIC 101 Single Constraint

Case Control

Create Modeling Object (Contact Parameters) Contact Changes for ConvergenceNumber of Contact Changes

Allowable Number of Contact Changes20

Contact StatusStart from Previous

Initial Penetration / gapSet to Zero

OKall dialog boxes

Simulation Navigator Subcase - Static Loads 1 Rename Preload Only

Define contact

Define contact between the red face of the shaft and the yellow face of the pulley. You need to turn on and off the visibility of the polygon bodies so that you can easily select the correct faces.Simulation Navigator wheel_fem1.fem (expand) 3D Collectors (deselect to turn off the display of both meshes) Polygon Geometry (expand) Polygon Body_1 (deselect to turn off the display of the pulley body) Surface-to-Surface Contact (Advanced Simulation toolbar, Simulation Object Type list) TypeManual

Source Region Target Region the Surface-to-Surface Contact dialog box title bar, to hide it Simulation Navigator Polygon Body_1 (select) Polygon Body_2 (deselect to turn off the display of the shaft body) the Surface-to-Surface Contact dialog box title bar, to restore it Properties

Source Offset0.05

Note:This simulates a 0.1 mm press fit on the diameter. OK

Polygon Body_2 (select)

Define constraints

Define a fixed constraint and a user-defined constraint that fixes the Tt (theta) and Tz (axial) displacement of the outer polygon edge on the X face of the pulley hub. Fixed Constraint (Advanced Simulation toolbar, Constraint Type list) Type FilterPolygon Face

Tip: The Type Filter is located on the Selection bar in the toolbar area.

OK

Simulation Navigator Polygon Body_2 (deselect to turn off the display of the shaft body) User Defined Constraint (Advanced Simulation toolbar, Constraint Type list) Type Filter (Selection bar) Polygon Edge

(edge of X face of the pulley hub)

Displacement CSYSCylindrical

Inferred (Local list) (edge of X face of the pulley hub)

The cylindrical coordinate system is inferring its location from this edge. DOF2Fixed

DOF3Fixed

OK

Display the pulley

Simulation Navigator Polygon Body_2 (select) Save (Standard toolbar)

Solve the model

Simulation NavigatorNote:This solution will take a few minutes on a desktop PC. Solution 1 Solve OK

Wait for the job to finish and for the command window to close.the Information window Cancel Analysis Job Monitor dialog box

Close Solution Monitor dialog box

View the analysis results

Simulation Navigator Results (under Solution 1) Post-Processing Navigator Solution_1 (expand) Displacement - Nodal (expand) Magnitude

When you finish looking at the results, return to the model.Return to Model (Layout Manager toolbar)

Define a new solution subcase

Define a new subcase to explore how a different load affects the part.Simulation Navigator Solution 1 Create Subcase NamePreload and Operating

OK

Define an operating load

Force (Advanced Simulation toolbar, Load Type list) Type Filter (Selection bar) Polygon Face

TypeNormal

Force5000

Distribution

MethodTotal per object

OK

Solve the model again

Simulation NavigatorNote:This solution will take a few minutes on a desktop PC. Solution 1 Solve OK

Wait for the job to finish and for the command window to close.the Information window Cancel Analysis Job Monitor dialog box

Close Solution Monitor dialog box

View the analysis results

Simulation Navigator ResultsPost-Processing Navigator Solution_1 (expand) Load Case 2 (expand) Displacement - Nodal (expand) Magnitude

Stress - Element Nodal (expand) Von-Mises

When you finish looking at the results, return to the model.Return to Model (Layout Manager toolbar) File Close All Parts