WS10a-1 WORKSHOP 10A MODAL ANALYSIS OF A CIRCUIT BOARD NAS122, Workshop 10a, August 2005 Copyright 2005 MSC.Software Corporation

WS10a-2 NAS122, Workshop 10a, August 2005 Copyright 2005 MSC.Software Corporation

WS10a-3 NAS122, Workshop 10a, August 2005 Copyright 2005 MSC.Software Corporation MODAL ANALYSIS OF A CIRCUIT BOARD n Problem Description u The purpose of this exercise is to prepare a Printed Circuit Board (PCB) for a Frequency Response Analysis. The user will import a MSC.Nastran Bulk Data file that contains the finite element definition of the PCB, assign the appropriate boundary conditions and submit the analysis for a Normal Modes Analysis. u After the analysis is completed, user will use MSC.Patran to post- process the results. The main objective is to observe the natural frequencies of the PCB because they will be important at verifying the results from a Frequency Response Analysis.

WS10a-4 NAS122, Workshop 10a, August 2005 Copyright 2005 MSC.Software Corporation MODAL ANALYSIS OF A CIRCUIT BOARD n Problem Description (cont.) u The following is a finite element representation of the Printed Circuit Board (PCB)

WS10a-5 NAS122, Workshop 10a, August 2005 Copyright 2005 MSC.Software Corporation MODAL ANALYSIS OF A CIRCUIT BOARD n Suggested Exercise Steps 1. Import the model from a Nastran Input File. 2. Create the boundary conditions. 3. Submit the model to MSC.Nastran for analysis. 4. Attach the.XDB results file. 5. Post Process results – create a Deformation and Fringe Plot of the eigenvectors of the normal modes.

WS10a-6 NAS122, Workshop 10a, August 2005 Copyright 2005 MSC.Software Corporation CREATE NEW DATABASE Create a new database called ws10a.db. a.File / New. b.Enter ws10a 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

WS10a-7 NAS122, Workshop 10a, August 2005 Copyright 2005 MSC.Software Corporation Step 1. File / Import Import the model from a Nastran Input file. a.File / Import. b.Select MSC.Nastran Input as the Source. c.Select pcb.bdf and click Apply. d.Click OK when the Nastran Input File Import Summary appears. b c a

WS10a-8 NAS122, Workshop 10a, August 2005 Copyright 2005 MSC.Software Corporation Step 2. Loads/BCs: Create / Displacement / Nodal Create the boundary condition. a.Loads/BCs: Create / Displacement / Nodal. b.Enter constraint for the New Set Name. c.Click on the Input Data button. d.Enter for Translations. e.Click OK. f.Click on Select Application Region. g.Change the Geometry Filter to FEM. h.Select the 4 corner nodes showed on the next page. i.Click Add, and click OK. j.Click Apply. a b c d e f g h i j i

WS10a-9 NAS122, Workshop 10a, August 2005 Copyright 2005 MSC.Software Corporation Step 2. Loads/BCs: Create / Displacement / Nodal (Cont.)

WS10a-10 NAS122, Workshop 10a, August 2005 Copyright 2005 MSC.Software Corporation Step 3. Analysis: Analyze / Entire Model / Full Run Submit the model for analysis. a.Analysis: Analyze / Entire Model / Full Run. b.Enter ws10a for the Job Name. c.Click on Solution Type. d.Select NORMAL MODES. e.Click on Solution Parameter button. f.Enter for Wt-Mass Conversion. g.Click OK. h.Click OK. i.Click Apply. a b c d e h g f i

WS10a-11 NAS122, Workshop 10a, August 2005 Copyright 2005 MSC.Software Corporation Step 4. Analysis: Access Results / Attach XDB / Result Entities Attach the XDB result file. a.Analysis: Access Results / Attach XDB / Result Entities. b.Click on Select Result File. c.Select ws10a.xdb. d.Click OK. e.Click Apply. a b c d e

WS10a-12 NAS122, Workshop 10a, August 2005 Copyright 2005 MSC.Software Corporation Step 5. Results: Create / Quick Plot Create a Deformation and Fringe plot of the normal modes. a.Change the view to Iso View 3. b.Results: Create / Quick Plot. c.Select the Mode 1. d.Select Eigenvector, Translational in both Result boxes. e.Click Apply. f.Repeat the same procedures for the remaining 9 normal modes. b c d e a d

WS10a-13 NAS122, Workshop 10a, August 2005 Copyright 2005 MSC.Software Corporation Summary Summary of Frequencies and Modes for project _______________ ModeFreq (Hz) Description

WS10a-14 NAS122, Workshop 10a, August 2005 Copyright 2005 MSC.Software Corporation