研讨会模态频率响应分析培训nastran.pdf

WORKSHOP6

MODALFREQUENCYRESPONSE

ANALYSIS

NAS122,Workshop6,August2005

Copyright©2005MSC.SoftwareCorporationWS6-1

MODALFREQUENCYRESPONSE

ProblemDescription

UsingtheModalMethod,determinethefrequencyresponseofthe

flatrectangularplate,createdinWorkshop1a,excitedbya0.1psi

pressureloadoverthetotalsurfaceoftheplateanda1.0lb.force

atacornerofthetiplagging45.Useamodaldampingof

0.03.Useafrequencystepof20Hzbetweenarangeof20and

1000Hz;inaddition,specifyfiveevenlyspacedexcitation

frequenciesbetweenthehalfpowerpointsofeachresonant

frequencybetweentherangeof20-1000Hz.

MODALFREQUENCYRESPONSE

ProblemDescription(cont.)

Belowisafiniteelementrepresentationoftheflatplate.Italso

containstheloadsandboundaryconstraints.

0.1psi.overthetotalsurface

1.0

MODALFREQUENCYRESPONSE

SuggestedExerciseSteps

1.ImportthemodelfromWorkshop1a.

2.Createanon-spatialfieldforthepressureloadandtheforceload.

3.Createatimedependentloadcase.

4.Createthetimedependentforceload.

5.Createthetimedependentpressureload.

6.SubmitthemodeltoMSC.Nastranforanalysis.

7.Attachthe.XDBresultsfile.

8.PostProcessresults–createXvsYgraphofdisplacements.

CREATENEWDATABASE

a

d

Createanewdatabasecalled

ws6.db.

a.File/New.