Axisymmetric Rotating Disk Workshop 3A Optimizing the Design

Workshop Supplement January 30, 2001 Inventory # WS3-2 3A. Optimizing the Design Axisymmetric Rotating Disk Description A high-speed rotating disk made of steel is to be designed for nearly uniform stress distribution at an operating speed of 15,000 rpm. Design constraints are as follows: –Maximum equivalent stress < psi –First natural frequency > 1000 Hz  rim y mid 10.0R 4.0R  hub x mid Properties: E = 30e6 psi  = 7.2e-4 lb-s 2 /in 4 = 0.3

Workshop Supplement January 30, 2001 Inventory # WS3-3 3A. Optimizing the Design...Axisymmetric Rotating Disk Instructions 1.Enter ANSYS (or clear the database) and change the jobname to rotdisk. 2.Establish the initial design by reading in the analysis file rotdisk.lgw (which was created in Workshop 2A). –Utility Menu > File > Read Input from… Double click on rotdisk.lgw 3.Enter the optimizer and identify the analysis file. –Main Menu > Design Opt > -Analysis File- Assign… Choose rotdisk.lgw and press [OK]

Workshop Supplement January 30, 2001 Inventory # WS3-4 3A. Optimizing the Design...Axisymmetric Rotating Disk 4.Identify optimization variables. 4a.Design variables: –(Design Opt) > Design Variables… [Add…] –NAME = THETAHUB –MIN = 30 –MAX = 90 –[Apply] –NAME = THETARIM –MIN = 45 –MAX = 135 –[Apply]

Workshop Supplement January 30, 2001 Inventory # WS3-5 3A. Optimizing the Design...Axisymmetric Rotating Disk 4a.Design variables (continued): –NAME = XMID –MIN = 0.5 –MAX = 4.5 –TOLER = 0.05 –[Apply] –NAME = YMID –MIN = 0.25 –MAX = 1.5 –TOLER = 0.05 –[OK] [Close]

Workshop Supplement January 30, 2001 Inventory # WS3-6 3A. Optimizing the Design...Axisymmetric Rotating Disk 4b.State variables: –(Design Opt) > State Variables… [Add…] –NAME = SMAX –MIN = leave blank –MAX = –[Apply] –NAME = FREQ2 –MIN = 1000 –MAX = leave blank –[OK] [Close]

Workshop Supplement January 30, 2001 Inventory # WS3-7 3A. Optimizing the Design...Axisymmetric Rotating Disk 4c.Objective function: –(Design Opt) > Objective… NAME = SDEV [OK] 5.Run the optimization. This involves specifying run-time controls and the method, saving the optimization database, and executing the run. 5a.Run-time controls: –(Design Opt) > Controls… Change OPKEEP setting from “Do not save” to “Save” [OK]

Workshop Supplement January 30, 2001 Inventory # WS3-8 3A. Optimizing the Design...Axisymmetric Rotating Disk 5b.Optimization method: –(Design Opt) > Method/Tool… MNAME = Sub-Problem [OK] [OK] on the next dialog 5c.Save the OPT database: –(Design Opt) > -Opt Database- Save… Enter rotdisk.opt0 as the file name [OK] 5d.Execute the run: –(Design Opt) > Run… Review the settings and press [OK]

Workshop Supplement January 30, 2001 Inventory # WS3-9 3A. Optimizing the Design...Axisymmetric Rotating Disk 6.Review results: start by listing design sets, then graph the objective function and state variables versus set number. 6a.Design set listing: –(Design Opt) > -Design Sets- List… List option = ALL sets [OK]

Workshop Supplement January 30, 2001 Inventory # WS3-10 3A. Optimizing the Design...Axisymmetric Rotating Disk 6b.Graphs: –(Design Opt) > Graphs/Tables… X-variable parameter = Set number Y-variable parameter = SDEV [OK]

Workshop Supplement January 30, 2001 Inventory # WS3-11 3A. Optimizing the Design...Axisymmetric Rotating Disk 6b.Graphs (continued): –(Design Opt) > Graphs/Tables… X-variable parameter = Set number Y-variable parameter = SMAX. (Also unhighlight SDEV by clicking on it.) [OK]

Workshop Supplement January 30, 2001 Inventory # WS3-12 3A. Optimizing the Design...Axisymmetric Rotating Disk 7.The next step in reviewing results is to restore the best design. First, however, we will save the optimization database to a file. –(Design Opt) > -Opt Database- Save… Filename = rotdisk.opt1 [OK] –Main Menu > Finish –Input window: resume,rotdisk,bdb /post1 file,rotdisk,brst lplot

Workshop Supplement January 30, 2001 Inventory # WS3-13 3A. Optimizing the Design...Axisymmetric Rotating Disk 7.(continued) –Main Menu > General Postproc > -Read Results- First Set –(General Postproc) > Plot Results > Nodal Solu… Item, Comp = Stress, von Mises SEQV [OK]

Workshop Supplement January 30, 2001 Inventory # WS3-14 3A. Optimizing the Design...Axisymmetric Rotating Disk 8.This workshop is now complete. If time permits, continue the optimization with: –a tighter objective function tolerance –only feasible designs selected Otherwise, exit ANSYS without saving the database.

Hexagonal Steel Plate Workshop 3B Optimizing the Design

Workshop Supplement January 30, 2001 Inventory # WS3-16 3B. Optimizing the Design Hexagonal Steel Plate Description An overdesigned steel plate under tension loading of 50 MPa needs to be optimized for minimum weight subject to a maximum von Mises stress limit of 150 MPa. You are allowed to vary the thickness t1 and fillet radius fil. Properties: –Thickness = 10 mm –E = 2.07e5 MPa – = t1 fil

Workshop Supplement January 30, 2001 Inventory # WS3-17 3B. Optimizing the Design...Hexagonal Steel Plate Instructions 1.Enter ANSYS (or clear the database) and change the jobname to hexplate. 2.Establish the initial design by reading in the analysis file hexplate.lgw (which was created in Workshop 2B). –Utility Menu > File > Read Input from… Double click on hexplate.lgw 3.Enter the optimizer and identify the analysis file. –Main Menu > Design Opt > -Analysis File- Assign… Choose hexplate.lgw and press [OK]

Workshop Supplement January 30, 2001 Inventory # WS3-18 3B. Optimizing the Design...Hexagonal Steel Plate 4.Identify optimization variables. 4a.Design variables: –(Design Opt) > Design Variables… [Add…] –NAME = FIL –MIN = 5 –MAX = 10 –[Apply] –NAME = T1 –MIN = 20.5 –MAX = 35 –[OK] [Close]

Workshop Supplement January 30, 2001 Inventory # WS3-19 3B. Optimizing the Design...Hexagonal Steel Plate 4b.State variables: –(Design Opt) > State Variables… [Add…] –NAME = SMAX –MIN = leave blank –MAX = 150 –[OK] [Close] 4c.Objective function: –(Design Opt) > Objective… NAME = VTOT TOLER = 1.0 [OK]

Workshop Supplement January 30, 2001 Inventory # WS3-20 3B. Optimizing the Design...Hexagonal Steel Plate 5.Run the optimization. This involves specifying run-time controls and the method, saving the optimization database, and executing the run. 5a.Run-time controls: –(Design Opt) > Controls… Change OPKEEP setting from “Do not save” to “Save” [OK] 5b.Optimization method: –(Design Opt) > Method/Tool… MNAME = Sub-Problem [OK] [OK] on the next dialog

Workshop Supplement January 30, 2001 Inventory # WS3-21 3B. Optimizing the Design...Hexagonal Steel Plate 5c.Save the OPT database: –(Design Opt) > -Opt Database- Save… Filename = hexplate.opt0 [OK] 5d.Execute the run: –(Design Opt) > Run… Review the settings and press [OK]

Workshop Supplement January 30, 2001 Inventory # WS3-22 3B. Optimizing the Design...Hexagonal Steel Plate 6.Review results: start by listing design sets, then graph the objective function and state variables versus set number. 6a.Design set listing: –(Design Opt) > -Design Sets- List… List option = ALL sets [OK]

Workshop Supplement January 30, 2001 Inventory # WS3-23 3B. Optimizing the Design...Hexagonal Steel Plate 6b.Graphs: –(Design Opt) > Graphs/Tables… X-variable parameter = Set number Y-variable parameter = VTOT [OK]

Workshop Supplement January 30, 2001 Inventory # WS3-24 3B. Optimizing the Design...Hexagonal Steel Plate 6b.Graphs (continued): –(Design Opt) > Graphs/Tables… X-variable parameter = Set number Y-variable parameter = SMAX. (Also unhighlight VTOT by clicking on it.) [OK]

Workshop Supplement January 30, 2001 Inventory # WS3-25 3B. Optimizing the Design...Hexagonal Steel Plate 7.The next step in reviewing results is to restore the best design. First, however, we will save the optimization database to a file. –(Design Opt) > -Opt Database- Save… Filename = hexplate.opt1 [OK] –Main Menu > Finish –Input window: resume,hexplate,bdb /post1 file,hexplate,brst lplot

Workshop Supplement January 30, 2001 Inventory # WS3-26 3B. Optimizing the Design...Hexagonal Steel Plate 7.(continued) –Main Menu > General Postproc > -Read Results- First Set –(General Postproc) > Plot Results > Nodal Solu… Item, Comp = Stress, von Mises SEQV [OK]

Workshop Supplement January 30, 2001 Inventory # WS3-27 3B. Optimizing the Design...Hexagonal Steel Plate 8.Exit ANSYS: –Toolbar > QUIT Choose Quit - No Save!, then [OK]