FEMAP Structural Analysis Toolkit for NASTRAN Carl Poplawsky Maya Simulation Technologies 1
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 2
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 3
Femap SA-Toolkit suite Mass processor Stress processor Grid point force processor Element force processor Energy Processor Modal processor Sine processor Random processor 4
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) 5
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 beam.inp Line, pie and bar graphs 90.0% 80.0% 70.0% PERCENT EFFECTIVE MASS 60.0% 50.0% 40.0% 30.0% Mx (%) My (%) Mz (%) 20.0% 10.0% 0.0% 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 MODE M O D E S U M M A R Y Effective Mass Filter 1.10% Response Filter 30.00 G S Mode Freq (Hz) Mx(% ) My(% ) Mz(% ) Response Load Case Node Group Name 1 10.185 60.40% 0.00% 0.00% 38.27 1 6 ALL NODES 2 20.372 0.00% 0.00% 60.45% 38.26 3 6 ALL NODES 3 61.032 18.95% 0.00% 0.00% 19.31 1 6 ALL NODES 4 121.308 0.00% 0.00% 19.03% 19.31 3 6 ALL NODES 5 164.067 6.45% 0.00% 0.00% 8.97 1 6 ALL NODES 6 304.130 3.08% 0.00% 0.00% 6.33 1 2 ALL NODES 7 322.451 0.00% 0.00% 6.46% 8.97 3 6 ALL NODES 8 442.152 1.12% 0.00% 0.00% 3.43 1 3 ALL NODES 9 586.438 0.00% 0.00% 3.02% 7.37 2 6 ALL NODES 10 640.168 0.00% 79.73% 0.00% 31.58 2 6 ALL NODES 11 835.330 0.00% 0.00% 1.03% 3.30 3 3 ALL NODES 12 1857.840 0.00% 7.70% 0.00% 9.79 2 6 ALL NODES 13 2893.656 0.00% 2.00% 0.00% 5.83 2 2 ALL NODES 14 3646.219 0.00% 0.52% 0.00% 3.67 2 6 ALL NODES 15 4041.859 0.00% 0.05% 0.00% 1.27 2 6 ALL NODES 6
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 7
Mass Processor 8
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 consistent fashion Resulting margins of safety can be graphically displayed in Femap 9
Stress processor Different failure cases 10
Stress Processor Summary Worksheet Summarize margins of safety for many element groups, several Nastran subcases and different safety factors 11
Detailed MS Excel Worksheets As many worksheets as there are combinations of subcases and userdefined stress cases Stress Processor 12
Composites and Sandwiches Stress Processor First ply failure, margins of safety using NASTRAN PCOMP output Margins of Safety in Femap Facesheet instability (ref. NASA CR1457) Wrinkling Intracell buckling Shear crimping Facesheet Stresses 13
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 14
Grid Point Force / Joints 15
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 16
Element Force processor (springs) MS Excel output of spring forces Rs 3 + Ra 2 = 1 Example of bolt margin calculation in MS Excel using spring force data 17
Element Force processor (laminate shells) Uses modified NASTRAN solution sequence Query element forces in material coordinate system Important for laminates applications Core shear analysis 18
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 19
Modal Processor 20
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 21
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 22
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 23
Random Processor 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) 24
Random Processor User Interface 25
Random Processor MS Excel output 26
Random Processor HTML output ASCII output 27
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 28
Thank You! www.mayasim.com carl.poplawsky@mayasim.com Booth 5005 (Design Expo) 29