WS12b-1 WORKSHOP 12B MODAL ANALYSIS FOR PRESTIFFENED TURBINE BLADE AT DIFFERENT RPM y x z 5,000 rpm Fixed edge displacements NAS122, Workshop 12b, August 2005 Copyright 2005 MSC.Software Corporation

WS12b-2 NAS122, Workshop 12b, August 2005 Copyright 2005 MSC.Software Corporation

WS12b-3 NAS122, Workshop 12b, August 2005 Copyright 2005 MSC.Software Corporation n Problem Description u Perform a modal analysis of jet engine turbine blade when it is operating at 5,000 rpm or 50,000 rpm. Use SOL 103 or SOL 106. A previous static analysis at 5,000 rpm was performed, and the corresponding MSC.Nastran.bdf file is provided. y x z 5,000 rpm Fixed edge displacements

WS12b-4 NAS122, Workshop 12b, August 2005 Copyright 2005 MSC.Software Corporation n Suggested Exercise Steps 1. Import the turbine blade model that is in a.bdf file. 2. Create a new load case named 50000rpm. 3. Create and assign a new inertial load, for rpm, to the second (latest) load case. 4. Create an input file (Analysis Deck) for MSC.Nastran using SOL Edit the.bdf file to change from SOL 106 (nonlinear static analysis) to SOL 103 (modal analysis) with pre-load. To include pre-load for SOL 103 it is necessary to use STATSUB Case Control entries. 6. Perform an MSC.Nastran modal analysis using SOL Review the.f06 file from the SOL 103 analysis. 8. Perform a normal modes analysis, using SOL 106, for each of the two subcases for pre-stiffening (5000 rpm and rpm), directly from within MSC.Patran. 9. Examine the.f06 file from the analysis using the SOL 106 method.

WS12b-5 NAS122, Workshop 12b, August 2005 Copyright 2005 MSC.Software Corporation CREATE NEW DATABASE Create a new database called ws12b.db. a.File / New. b.Enter ws12b as the file name. c.Click OK. d.Choose Default Tolerance. e.Select MSC.Nastran as the Analysis Code. f.Select Structural as the Analysis Type. g.Click OK. a b c d e f g

WS12b-6 NAS122, Workshop 12b, August 2005 Copyright 2005 MSC.Software Corporation Step 1. File / Import Import the model from the turb_blade_stat.bdf file. a.File / Import. b.Select MSC.Nastran Input as the Source. c.Select turb_blade_stat.bdf. d.Click Apply. e.Click OK when the Nastran Input File Import Summary appears. a b c d e

WS12b-7 NAS122, Workshop 12b, August 2005 Copyright 2005 MSC.Software Corporation Step 2. Load Cases: Create Create a second load case. a.Load Cases: Create. b.Enter 50000rpm for the Load Case Name. c.Select Static as the Load Case Type. d.Click Assign/Prioritize Loads/ BCs. e.Select Displ_grid.ps and Displ_spc1.1 in the Select Individual Loads/BCS field. f.Click OK. g.Click Apply. a b c d e f g

WS12b-8 NAS122, Workshop 12b, August 2005 Copyright 2005 MSC.Software Corporation Step 3. Create an Inertial Load for RPM Create an Inertial Load for 50,000 rpm. a.Loads/BCs: Create/ Inertial Load/Element Uniform. b.Enter 50000rpm for the New Set Name. c.Click on the Input Data button. d.Enter for Rot Velocity. e.Select Coord 1 for the Analysis Coordinate Frame. f.Click OK. g.Click Apply. a b c d e f g

WS12b-9 NAS122, Workshop 12b, August 2005 Copyright 2005 MSC.Software Corporation Step 4. Analysis: Analyze / Entire Model / Analysis Deck Submit the model with the Nonlinear loading condition included. a.Analysis: Analyze / Entire Model / Analysis Deck. b.Enter turb_blade_5k_50k_SOL103 for the Job Name. c.Click on Solution Type. d.Select NONLINEAR STATIC. e.Click on Solution Parameters button. f.Uncheck Large Displacements. g.Enter for Wt-Mass Conversion. h.Click OK. i.Click OK. a c d e h i f g b

WS12b-10 NAS122, Workshop 12b, August 2005 Copyright 2005 MSC.Software Corporation Step 4. Analysis: Analyze / Entire Model / Analysis Deck (Cont.) Submit the model for Nonlinear Analysis (cont.). a.Click on Subcase Select… b.Select 5000_RPM.SC1 and 50000rpm and unselect Default. c.Click OK. d.Click Apply. b c d a

WS12b-11 NAS122, Workshop 12b, August 2005 Copyright 2005 MSC.Software Corporation Step 5. Modify MSC.Nastran Input File Modify.bdf file generated from this analysis. a.Change the Solution Type from SOL 106 to SOL 103. b.Delete the NLPARM case control command. c.Delete the NLPARM command line from the Bulk Data Section. b c a b

WS12b-12 NAS122, Workshop 12b, August 2005 Copyright 2005 MSC.Software Corporation Step 5. Modify MSC.Nastran Input File (Cont.) Insert the necessary MSC.Nastran commands into the.bdf file to perform the normal modes analysis for prestiffening. a.Insert SUBCASE 3 for doing normal modes analysis using stiffness from Subcase 1. b.Insert SUBCASE 4 for doing normal modes analysis using stiffness from Subcase 2. c.Insert EIGRL command in the bulk data section. d.Insert STATSUB = 1 e.Insert STATSUB = 2 c a b d e

WS12b-13 NAS122, Workshop 12b, August 2005 Copyright 2005 MSC.Software Corporation Step 6. Execute the MSC.Nastran Analysis Execute MSC.Nastran outside of MSC.Patran. a.Select turb_blade_5k_50k_SOL103. bdf from the window. b.Click on Open. c.Type scr=yes in the Optional Keywords section. d.Click Run. b c d a

WS12b-14 NAS122, Workshop 12b, August 2005 Copyright 2005 MSC.Software Corporation Step 7. Review the.f06 file Load Case 1: 5,000 rpm Load Case 2: 50,000 rpm

WS12b-15 NAS122, Workshop 12b, August 2005 Copyright 2005 MSC.Software Corporation Next, perform the same analysis but using the SOL 106 method in MSC.Patran/MSC.Nastran.

WS12b-16 NAS122, Workshop 12b, August 2005 Copyright 2005 MSC.Software Corporation Step 8. Analysis: Analyze / Entire Model / Full Run Now, perform the normal modes analyses for multiple prestiffened load cases using SOL106. a.Analysis: Analyze / Entire Model / Full Run. b.Enter turb_blade_5k_50k_SOL106 for the Job Name. c.Click on Solution Type. d.Select NONLINEAR STATIC. e.Click on Solution Parameters button. f.Check Large Displacements. g.Enter for Wt-Mass Conversion. h.Click OK. i.Click OK. a c d e h i f g b

WS12b-17 NAS122, Workshop 12b, August 2005 Copyright 2005 MSC.Software Corporation j i Step 8. Analysis: Analyze / Entire Model / Full Run (Cont.) Now, perform the normal modes analyses for multiple prestiffened load cases using SOL106 (continued). a.Click on Subcases. b.Select 5000_RPM.SC1 from the Available Subcases box. c.Click on Subcase Parameters. d.Check the Normal Modes option. e.Click OK. f.Click Apply. g.Click Yes when message appears h.Repeat the same procedures from Step a to g for the 50000rpm subcase. i.Click Cancel j.Click Apply a b c f d e

WS12b-18 NAS122, Workshop 12b, August 2005 Copyright 2005 MSC.Software Corporation Step 9. Review the.f06 file Load Case 1: 5000 rpm Load Case 2: 50,000 rpm