femap structural analysis toolkit for nastran - … 2006/best... · 1 femap structural analysis...

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FEMAP Structural Analysis Toolkit for NASTRAN

Carl PoplawskyMaya Simulation Technologies

© 2006, MAYA HTT Ltd.2

Who is Maya Simulation Technologies?� American subsidiary of Maya Heat Transfer

Technologies (Montreal)� Offices in Boston, Dallas, and Phoenix

� MAYA is a UGS Foundation Partner (1984)� Fully integrated software solutions for NX, I-

deas, and FEMAP

� MAYA-authored products are sold by UGS and Maya worldwide

• NX Thermal / NX Flow• I-deas TMG / I-deas ESC• Laminates Module (I-deas & NX)• FEMAP TMG / FEMAP Flow• Structural Analysis Toolkit• I-deas & NX ECAD/MCAD and FE

Translators

� Platinum Value-Added Reseller of UGS� Engineering Consulting Services worldwide


Femap SA-Toolkit for NASTRAN

� Developed and sold directly by Maya� Efficient post-processing of NASTRAN

results� Ranking, sorting, enveloping, filtering� Summaries by groups, subcases� Margins of safety � Random and harmonic solutions from

NASTRAN normal modes results� Direct manipulation of .op2 file data from NX

NASTRAN and MSC.NASTRAN� Extremely efficient for large models

� Automatic Report Generation� HTML, MS Excel®, Ascii


Femap SA-Toolkit suite

� Mass processor� Stress processor� Grid point force processor� Element force processor� Energy Processor� Modal processor� Sine processor� Random processor


OS Support Summary

� Uses NASTRAN data directly from binary results file (op2)• UNIX/WINDOWS/LINUX cross-platform binary file reading capability

� Toolkit OS platforms• Windows (from Femap APIs directly)• Linux - 32/64 bit (standalone)


MS Excel report writer

�All processors write data directly to MS Excel• Automatic creation of sort keys to allow efficient manipulation

of data and analysis • Special fonts and shadings to highlight key results like

negative margins• Line, pie and bar graphs

M O D E S U M M A R Y

E ffec tive M ass F ilte r 1 .10%R esp o n se F ilte r 30 .00 G S

M o d e F req (H z) M x(% ) M y(% ) M z(% ) R esp o n se L o ad C ase N o d e G ro u p N am e1 10 .185 60 .40% 0 .00% 0 .00% 38 .27 1 6 A LL N O D E S2 20 .372 0 .00% 0 .00% 60 .45% 38 .26 3 6 A LL N O D E S3 61 .032 18 .95% 0 .00% 0 .00% 19 .31 1 6 A LL N O D E S4 121 .308 0 .00% 0 .00% 19 .03% 19 .31 3 6 A LL N O D E S5 164 .067 6 .45% 0 .00% 0 .00% 8 .97 1 6 A LL N O D E S6 304 .130 3 .08% 0 .00% 0 .00% 6 .33 1 2 A LL N O D E S7 322 .451 0 .00% 0 .00% 6 .46% 8 .97 3 6 A LL N O D E S8 442 .152 1 .12% 0 .00% 0 .00% 3 .43 1 3 A LL N O D E S9 586 .438 0 .00% 0 .00% 3 .02% 7 .37 2 6 A LL N O D E S

10 640 .168 0 .00% 79 .73% 0 .00% 31 .58 2 6 A LL N O D E S11 835 .330 0 .00% 0 .00% 1 .03% 3 .30 3 3 A LL N O D E S12 1857 .840 0 .00% 7 .70% 0 .00% 9 .79 2 6 A LL N O D E S13 2893 .656 0 .00% 2 .00% 0 .00% 5 .83 2 2 A LL N O D E S14 3646 .219 0 .00% 0 .52% 0 .00% 3 .67 2 6 A LL N O D E S15 4041 .859 0 .00% 0 .05% 0 .00% 1 .27 2 6 A LL N O D E S

beam.inp

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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

MODE

PE

RC

EN

T E

FFE

CTI

VE

MA

SS

Mx (%)

My (%)

Mz (%)


Mass processor

�Best practice purpose: To efficiently alter the mass properties of large FE models to bring them back to actual mass levels�Typically used to simulate the effects of non-structural

mass• Mass properties given by physical property and optionally by

user-defined element groups• Mass properties separated into structural and non structural

masses• Accounts for lumped masses, 1-d, 2-d, 3-d and laminate

elements


Mass Processor


Stress processor

�Best practice purpose: To summarize margins of safety for many element groups, several subcases and different safety factors� Supported failure theories:

• Von Mises, Laminates, Honeycomb Sandwich

� For each each group one can specify:• Factor of safety, Allowable Stress, MS threshold, Failure criteria

� Dynamic stresses are combined in a phase consistentfashion

� Resulting margins of safety can be graphically displayed in Femap


Stress processor – Different failure cases


Stress Processor

� Summary Worksheet– Summarize margins of safety for many element

groups, several Nastran subcases and different safety factors


Stress Processor

• Detailed MS Excel Worksheets– As many worksheets

as there are combinations of subcases and user-defined stress cases


Composites and Sandwiches

• First ply failure, margins of safety using NASTRAN PCOMP output

• Facesheet instability (ref. NASA CR1457)

• Wrinkling

• Intracell buckling

• Shear crimping

• Facesheet Stresses

Stress Processor

Margins of Safety in Femap


Grid point force processor

�Best practice purpose: To synthesize forces on groups of elements in complex geometries, for several subcases

• Typically used for bolt and joints detailed hand calculations

• Also used for laminate/composite joint analyses• Extract resulting forces at a grid point resulting from a user

specified group of elements• MPC, SPC forces and applied loads optionally considered• Complex grid point forces are accounted for in frequency

response analyses (SOL 108 and 111)• Resulting forces may be in a coordinate system other then

the grid displacement coordinate system


Grid Point Force / Joints


Element Force processor

�Best practice purpose: To efficiently summarize forces on elements for many element groups and several subcases, component by component

• Force output varies depending on element type

• Summaries make it easy to identify critical component and element

•Forces in material coordinate system


Element Force processor (springs)

123 =+ RaRs

• MS Excel output of spring forces

• Example of bolt margin calculation in MS Excel using spring force data


Element Force processor (laminate shells)

• Uses modified NASTRAN solution sequence

• Query element forces in material coordinate system

• Important for laminates applications

• Core shear analysis


Modal processor

� Best practice purpose: To provide all information required in preparation of modal forced response analysis� For each mode

• Effective mass • Maximum acceleration response estimation for excitation in all 3

translational directions, for user-selected node groups• Given a 1g base excitation over a bandwidth coincident with the modes

� Summary of all the modes that pass the following criteria:

• User-defined minimum effective mass • User-defined minimum dynamic response

� Processes multiple load cases


Modal Processor


Energy processor�Best practice purpose: To efficiently identify groups

with high energy in complex models, on a mode by mode basis

• Compute both kinetic and strain energy


Random processor

�Best practice purpose: To efficiently analyze a structure subjected to random-type base excitation

• Provides a wizard type capability to perform a NASTRAN base excitation random analysis

• Uses the results from a NASTRAN eigenvalue analysis• Simplified data entry compared to standard NASTRAN

analysis• PSD specified using typical power spectrum quantities• Elements/nodes specified using groups• All stress/force components processed for a given element• Exact Von Mises stress calculation from Monte Carlo or Segalman

approach


Random processor• Corrects for modal truncation by considering residual flexibility• Powerful Gauss-Kronrod numerical integration scheme

• Automatically picks integration points• Alternate analytical integration approach• Margins of safety calculated on groups of elements similar to the

stress processor• Resulting margins of safety can be displayed in Femap for graphical

display• Generate RMS and peak Von Mises stresses• Html PSD plots generated for selected quantities• PSD plots can be imported into excel or Femap for further

processing


� Traditional Von Mises stress recovery

• Typical workaround of combining stress components can result in overestimation of Von Mises stress

• Phasing is lost in this type of calculation• Time consuming for large models

� SAToolkit computes exact Von Mises stress using� Monte Carlo method� Segalman method (default)

Random Processor


Random Processor User Interface


Random Processor

MS Excel output


Random Processor

HTML output

ASCII output


Sine processor

�Best practice purpose: To efficiently analyze a structure subjected to harmonic base excitation

• Similar to random processor• Uses efficient modal approach with option to account for

modal truncation• Phase-consistent Von Mises Stresses

• Stress tensor is complex• Von Mises stress is a real value• Maximum possible Von Mises stress is computed for any

phasing of the stress tensor components

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Thank You!www.mayasim.com

[email protected] 5005 (Design Expo)

femap structural analysis toolkit for nastran - … 2006/best... · 1 femap structural analysis...

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