WS19-1 WORKSHOP 19 EFFECTIVE MASS NAS122, Workshop 19, August 2005 Copyright 2005 MSC.Software Corporation

WS19-2 NAS122, Workshop 19, August 2005 Copyright 2005 MSC.Software Corporation

WS19-3 NAS122, Workshop 19, August 2005 Copyright 2005 MSC.Software Corporation EFFECTIVE MASS n Problem Description u This workshop evaluates the modal effective mass for the beam model described in Section 2. u You are required to extract the modal effective mass fraction in the T1, T2, T3, R2 and R3 directions. u Please asses the significance of the Fraction Sum in each of the directions. u Feel free to ask your tutor if you have any problems.

WS19-4 NAS122, Workshop 19, August 2005 Copyright 2005 MSC.Software Corporation EFFECTIVE MASS n Suggested Exercise Steps 1. Import a Nastran Input File that contains the model description. 2. Add the command, MEFFMASS(ALL)=YES into the Case Control Section of the Nastran Input File using the Direct Text Input feature in MSC.Patran. Submit the model to MSC.Nastran for analysis. 3. Open the.f06 file and observe the Mass Participation tables.

WS19-5 NAS122, Workshop 19, August 2005 Copyright 2005 MSC.Software Corporation CREATE NEW DATABASE Create a new database called effmass.db. a.File / New. b.Enter effmass 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

WS19-6 NAS122, Workshop 19, August 2005 Copyright 2005 MSC.Software Corporation Step 1. File / Import Import the Nastran Input File called beam.bdf. a.File / Import. b.Select MSC.Nastran Input File as the Source. c.Select beam.bdf. d.Click Apply. e.Click OK when the Patran Database Import Summary appears. a b c d e

WS19-7 NAS122, Workshop 19, August 2005 Copyright 2005 MSC.Software Corporation Step 2. Analysis: Analyze / Entire Model / Full Run Submit the model for analysis. a.Analysis: Analyze / Entire Model / Full Run. b.Enter effmass for the Job Name. c.Click on Solution Type. d.Select NORMAL MODES. e.Click on Solution Parameters button. f.Make sure the value for Wt.-Mass Conversion is 1.0. g.Click OK. h.Click OK. a b c d e h g f

WS19-8 NAS122, Workshop 19, August 2005 Copyright 2005 MSC.Software Corporation Step 2. Analysis: Analyze / Entire Model / Full Run (Cont.) Submit the model for analysis (cont.). a.Click on Direct Text Input. b.Check the Case Control Section option. c.Make sure the CASE Write to Input Deck option is checked. d.Enter MEFFMASS(ALL)=YES in the above field. e.Click OK. a b c d e

WS19-9 NAS122, Workshop 19, August 2005 Copyright 2005 MSC.Software Corporation Step 2. Analysis: Analyze / Entire Model / Full Run (Cont.) Submit the model for analysis (cont.). a.Click on Subcase Select… b.Select DEFAULT.SC1 from the Subcases for Solution Sequence, and unselect the Default from the Subcases Selected box. c.Click OK. d.Click Apply. a b c d

WS19-10 NAS122, Workshop 19, August 2005 Copyright 2005 MSC.Software Corporation Step 4. Study the F06 file after the MSC.Nastran analysis

WS19-11 NAS122, Workshop 19, August 2005 Copyright 2005 MSC.Software Corporation Summary Summary of Frequencies and Modes for project _______________ ModeFreq (Hz) Description

WS19-12 NAS122, Workshop 19, August 2005 Copyright 2005 MSC.Software Corporation