1. Axisymmetric Wheel Workshop 1 Array Parameters

2. Workshop Supplement October 30, 2001 Inventory #001572 W1-2 1. Array Parameters Axisymmetric Wheel Determine the standard deviation of the von Mises stress distribution in a steel wheel spinning at 7500 rpm. Given: A database file containing an axisymmetric model with material properties defined.

3. Workshop Supplement October 30, 2001 Inventory #001572 W1-3 1. Array Parameters Axisymmetric Wheel 1.Enter ANSYS in the working directory specified by your instructor using “axiwheel” as the jobname. 2.Resume the “axiwheel.db1” database file. 3.Constrain the bottom line in UY direction. –Main Menu > Soluion > -Loads- Apply > Displacement > On Lines –Or issue: /SOLU DL,1,,UY

4. Workshop Supplement October 30, 2001 Inventory #001572 W1-4 1. Array Parameters Axisymmetric Wheel 4.Apply a 7500-rpm angular velocity about the Y-axis. Since ANSYS requires radians/second units, we will use APDL to convert 7500 rpm to rad/sec. –Type in the Input window (or in the Scalar Parameters dialog): rpm=7500 pi=3.142 w=2*pi*rpm/60 –Main Menu > Solution > -Loads- Apply > Other > Angular Velocity … OMEGY = w, then [OK] –Or issue: OMEGA,,W 5.Save the database and solve.

5. Workshop Supplement October 30, 2001 Inventory #001572 W1-5 1. Array Parameters Axisymmetric Wheel 6.Plot von Mises stress contours in POST1 (general postprocessor). 7.If desired, expand the axisymmetric solution to 270°. –Utility Menu > PlotCtrls > Style > Symmetry Expansion > 2-D Axisymmetric … Expansion amount = 3/4 expansion [OK] –Utility Menu > PlotCtrls > Pan,Zoom,Rotate… [ISO] –Or issue: /EXPAND,27,AXIS,,,10 /VIEW,1,1,1,1 /REPLOT

6. Workshop Supplement October 30, 2001 Inventory #001572 W1-6 1. Array Parameters Axisymmetric Wheel 8.We will use the element table and array parameters to calculate the standard deviation of von Mises stresses. First load equivalent stresses into the element table: –Main Menu > General Postproc > Element Table > Define Table … [Add…] –Lab = eseqv –Item, Comp = Stress, von Mises SEQV –[OK] [Close] –Or issue: ETABLE,ESEQV,S,EQV

7. Workshop Supplement October 30, 2001 Inventory #001572 W1-7 1. Array Parameters Axisymmetric Wheel 9.Plot and list the element table values. –Utility Menu > PlotCtrls > Style > Symmetry Expansion > No Expansion –Main Menu > General Postproc > Element Table > Plot Elem Table … Itlab = ESEQV Avglab = Yes - average [OK] –Utility Menu > PlotCtrls > Pan,ZOOM,Rotate… [Front] –Main Menu > General Postproc > Element Table > List Elem Table … Lab1-9 = ESEQV [OK] –Or issue: /EXPAND PLETAB,ESEQV,1 /VIEW,1,1,1,1 /REPLOT PRETAB

8. Workshop Supplement October 30, 2001 Inventory #001572 W1-8 1. Array Parameters Axisymmetric Wheel 10.We now need to "upload" the element table values into an array parameter. First dimension an array with number of rows = number of elements: –Utility Menu > Parameters > Get Scalar Data … Type of data = Model data, For selected set; then [OK] Name of parameter = nelem Data to be retrieved = Current elem set, Number of elem's [OK] –Utility Menu > Parameters > Array Parameters > Define/Edit … [Add…] –Par = sarray –Type = Array –I, J, K = nelem, 1, 1 –[OK] [Close] –Or issue: *GET,NELEM,ELEM,,COUNT *DIM,SARRAY,,NELEM

9. Workshop Supplement October 30, 2001 Inventory #001572 W1-9 1. Array Parameters Axisymmetric Wheel 11.Fill the array with von Mises stress values from the element table. –Utility Menu > Parameters > Get Array Data … Type of data = Results data, Elem table data; then [OK] Name of array parameter = sarray(1) Elem table item to be retrieved = ESEQV Fill array by looping on = Element number [OK] –Or issue: *VGET,SARRAY(1),ELEM,1,ETAB,ESEQV 12.Verify the values in the array parameter. –Utility Menu > List > Status > Parameters > Named Parameter … Par = SARRAY [OK] –Or issue: *STAT,SARRAY

10. Workshop Supplement October 30, 2001 Inventory #001572 W1-10 1. Array Parameters Axisymmetric Wheel 13.Calculate the standard deviation. –Utility Menu > Parameters > Array Operations > Vector-Scalar Func … ParR = sdev Par1 = sarray(1) Func = Std deviatn STDV [OK] –Utility Menu > Parameters > Scalar Parameters … Check the value of SDEV [Close] –Or issue: *VSCFUN,SDEV,STDV,SARRAY(1) *STAT,SDEV 14.If time permits, rerun the solution with the addition of a UX=0 constraint on the inner face of the wheel, calculate the standard deviation, and compare with the previous value. 15.Exit ANSYS.