MSC Nastran 2021 What’s New
Al Robertson MSC Nastran Product Manager
1 | hexagonmi.com | mscsoftware.com Introduction and Agenda
2 | hexagonmi.com | mscsoftware.com Upcoming MSC Nastran Releases Timeline
2020 2021 Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
2021 2021.1 2021.2 2021.3 2021.4
• Quarterly release cadence • Faster response to customer requests, new capabilities and error fixes
• Change of release numbering • For greater simplicity and clarity
3 | hexagonmi.com | mscsoftware.com Feature Deprecation List
• Notice of features to be removed from MSC Nastran in 2020: • In an effort to streamline the MSC Nastran program and simplify ongoing maintenance activity, some obsolete capabilities have been identified and tagged for removal in a future release of the program in 2021 and 2022, allowing for a reasonable notice period. Please review the list of features marked for deprecation below to ensure that there will be no disruption to your use of MSC Nastran. If you see a feature that you currently use and do not wish to lose, contact MSC Technical Support to report it. • Features tagged for removal: • P-elements • SOL 600 nonlinear solution sequence – migration plan through 2021 • Unstructured one- and two-digit solution sequences (e.g. SOL 3, SOL 24) • SOL 190 (DBTRANS) • TAUCS solver • MSGMESH • Obsolete DMAP modules • SSSALTERS
4 | hexagonmi.com | mscsoftware.com MSC Nastran Documentation
5 | hexagonmi.com | mscsoftware.com MSC Nastran 2020 Internal Webinar Agenda
Introduction Dynamics Grid Point Forces in Frequency Response Rigid Elements TREF PEM Enhancements PEM Parallel Solution CDTire/NVH Linear Tire Model Coupled Modes for External Superelements Bent Rotor Modeling in Rotordynamics Fatigue CAEfatigue available in MSC Nastran Nonlinear SOL 400 Brake Squeal Enhancements Enhanced Segment to Segment Contact Settings ESE and EKE Output in SOL 400 Linear Perturbation Analysis HPC MUMPS Solver for SOL 101 Results Eigenvector Output with Lossy Compression SOL 700 DMP Support for Langrangian Solver
6 | hexagonmi.com | mscsoftware.com Dynamics
7 | hexagonmi.com | mscsoftware.com GPFORCE for Frequency Response Analysis
8 | hexagonmi.com | mscsoftware.com GPFORCE for Frequency Response Analysis Overview
Introduction • Extended GPFORCE options for explicit types of dynamic force output
Benefits • Important frequency dependent element data recovery feature • Element force/stress recovery only performed at Master Frequencies for frequency dependent elements • Thermal loading is correctly accounted for
Use Case • Load path analysis of structures – new for frequency response analysis • Aerospace customer request • Also serves defense, transportation and security markets
9 | hexagonmi.com | mscsoftware.com GPFORCE for Frequency Response Analysis Usage
• ALLDLDS outputs everything – elastic, inertia, damping forces • Implemented in SOL108, SOL111 or ANALYSIS=DFREQ or MFREQ for SOL 200 and linear SOL 400 • In general, for frequency response, the “*totals*“rows will not be zero, except when ALLDLDS is chosen • PARAM, BUSHNM, YES (default) required for GPFORCE. • GPFORCE is inherently a SORT1 output, SORT2 is suppressed
10 | hexagonmi.com | mscsoftware.com GPFORCE for Frequency Response Analysis Example Model: (..\tpl\gpf_frq\gpf108_wing.dat)
GPFORCE(ALLDLDS)=2
GPFORCE=ALL option, large Grid IDs ≥ 101000001 are from CWELD or CFAST or
CSEAM elements SWLDPRM, PRTSW,n: To see connector grids
SET 2 = 27188,20273,14783,113645,101002153,101002154
11 | hexagonmi.com | mscsoftware.com GPFORCE for Frequency Response Analysis Example Output .f06
Elastic forces
Damping forces (G)
Structural damping forces
Inertia forces (G)
…
Zero total (ALLDLDS requested) 12 | hexagonmi.com | mscsoftware.com GPFORCE for Frequency Response Analysis Example Output HDF5 – always stores in Real/Imaginary format
Grid ID Element ID Source
13 | hexagonmi.com | mscsoftware.com TREF Support for Rigid Elements
14 | hexagonmi.com | mscsoftware.com TREF Support for Rigid Elements Overview
Introduction • TREF support for rigid elements using TEMP(MATE) or TREF on elements (previously was zero)
Benefits • TREF support removes a previous limitation (unwanted constraint) with modeling rigid elements in a temperature field • Now supported in all linear solutions sequences that allow thermal effects
Use Case • In linear analysis with material dependency, rigid elements now reflect the local temperature field
15 | hexagonmi.com | mscsoftware.com TREF Support for Rigid Elements Usage
16 | hexagonmi.com | mscsoftware.com TREF Support for Rigid Elements Usage
17 | hexagonmi.com | mscsoftware.com TREF Support for Rigid Elements Usage
18 | hexagonmi.com | mscsoftware.com Porous Elastic Material Enhancements • Solid Shell using 3D Elements • Perforated Shell Elements • Simplified Biot Porous Material Models • Multiple Coupling Specifics for a Trim Component • TRMC Processing Scenarios • Rigid Elements for TRMC
19 | hexagonmi.com | mscsoftware.com Solid Shell Using 3D Elements
20 | hexagonmi.com | mscsoftware.com Solid Shell Using 3D Elements Overview
Introduction • Solid shell is used to model transverse solid elements, with a thickness direction • One dimension of the structure should be small compared with the two others (~ 1/15) • Thickness (and thus compression effects) are accounted for using solid shells Benefits • New modeling feature • For trim component only • Isotropic materials only Usage • Hexa/Penta/Tetra/PYRAM element types can be used • PSOLID entry FCTN field set to new PSLDSHL option (for PEM only) • MID field points to MAT1 (not MATPE1)
PSOLID PID MID CORDM IN STRESS ISOP FCTN PSOLID 1 1 PSLDSHL
21 | hexagonmi.com | mscsoftware.com Perforated Shell Elements
22 | hexagonmi.com | mscsoftware.com Perforated Shell Elements Overview
Introduction • Perforated shells are common in many acoustic systems • Avoids fine meshing of holes • Not suitable for precision modeling of perforation
Benefit • Reduce meshing effort • Minimize CPU time
23 | hexagonmi.com | mscsoftware.com Perforated Shell Elements Usage
• New MSC Nastran trim component bulk data entry PSHLPF • MID: solid material • T: thickness • SPACEG: spacing • RADIUS: radius • TOPOLGY: grid pattern (SQUARE / TRIA / HEXA) • FRHO: fluid density (air) • FVIS: viscosity • HOMG: homogenization (hole processing 0 or 1)
PSHLPF PID MID T SPACEG RADIUS TOPOLGY FRHO FVIS
HOMG
PSHLPF 1 2 8.1-4 1.132-2 1.245-3 SQUARE 1.225 1.71-5
24 | hexagonmi.com | mscsoftware.com Simplified Biot Porous Material Model
25 | hexagonmi.com | mscsoftware.com Simplified Biot Porous Material Models Overview
Introduction • Lumped porous • Model a porous medium when the material skeleton is assumed to be very soft (E=0) • Rigid porous • Model a porous medium when the material skeleton is assumed to be rigid • Delany-Bazley & Miki Porous • Semi-empirical numerical method for modeling porous materials • Assumes porosity = 1 • Only valid in a specific range (frequency/resistivity)
Benefits • Easier modeling process for skeleton conditions • One dof per node in TRMC, instead of 4 • Potential performance improvement on TRMC matrix generation
26 | hexagonmi.com | mscsoftware.com Simplified Biot Porous Material Models Usage
• On the Nastran side for trim component • POROPT: porous options (LUMPED, RIGID, MIKI or DELANY) • MAT1 field must be left blank if POROPT is RIGID, MIKI or DELANY • MAT1 field can be used for POROPT=LUMPED to provide SRHO • MAT1 field must have valid input (integer>0) if POROPT is blank • SRHO: solid density for LUMPED porous only • VLE – Blank or 0.0 is acceptable(=>0.0, default=0.0) • TLE – Blank or 0.0 is acceptable(=>0.0, default=0.0)
MATPE1 MID MAT1 MAT10 BIOT POROPT SRHO
VISC GAMMA PRANDTL POR TOR AFR VLE TLE
MATPE1 1 15 LUMPED 0.1
1.84-5 9.4-1 4.0+4
27 | hexagonmi.com | mscsoftware.com Multiple Coupling Settings for a Trim Component
28 | hexagonmi.com | mscsoftware.com Multiple Coupling Settings for a Trim Component Overview
Introduction • Coupling specifics are provided on a set of ACPEMCP / TRMCPL entries • The distance between the structure or trim component and cavity can vary • A single set of ACPEMCP / TRMCPL may not be suitable for all regions of a trim component • REGION ID (RID) is implemented to handle diverse coupling conditions of a trim component
Benefit • Coupling tolerances for a region of a trim component can be precisely defined • Better coupling between the structure or trim component and cavity without requiring model changes
29 | hexagonmi.com | mscsoftware.com Multiple Coupling Settings for a Trim Component Usage
• On Nastran side, for trim component • RID – region ID for ACPEMCP/TRMCPL (default=0) • ACPEMCP and TRMCPL with same TID and RID will be paired together • New design has minimum disturbance with existing PEM decks • FATAL if following conditions exist • TID,RID pair must be unique (trim and region IDs) • SET ID on ACPEMCP with different (TID,RID) pair must be different • OOC and SPM fields for RID>0 must be blank ACPEMCP TID SGLUED SSLIDE SOPEN SIMPER OOC SPM SAIRGAP SCUX SCUY SCUZ SCRX SCRY SCRZ SCFP RID
ACPEMCP 1 1002 1004 20
TRMCPL TID CTYPE PLTOL GAPTOL1 GAPTOL2 GAPTOL3 GAPTOL4 RID
TRMCPL 1 SSLIDE 0.12 5 20
30 | hexagonmi.com | mscsoftware.com Trim Component Processing Scenarios
31 | hexagonmi.com | mscsoftware.com Trim Component Processing Scenarios Overview
Introduction • Previously MSC Nastran supported: • Processing of all trim components whether referenced by TRIMGRP Case Control or not • MSC Nastran 2021 now supports ALLTRMC and SLTTRMC: • New keywords on the TRIMGRP Case Control Example: $ Sets for the TRIM 1 selection • ALLTRMC – processes TRMC as with previous releases SET 98 = 1 • SLTTRMC – processes selected TRMC only $ Sets for the TRIM 2 selection SET 97 = 2 Benefit TRIMGRP(SLTTRMC)=98 • Processing referenced by TRMC only in Actran • Performance improvements
32 | hexagonmi.com | mscsoftware.com Rigid Elements for the Trim Component
33 | hexagonmi.com | mscsoftware.com Rigid Elements for the Trim Component Overview
• In previous releases of MSC Nastran • Rigid elements under BEGIN TRMC=TRMID were ignored
• For MSC Nastran 2021 • RBE2 / RBE3 elements are processed as part of the TRMC model in Actran
34 | hexagonmi.com | mscsoftware.com New Parallel Solution for MSC Nastran-PEM
35 | hexagonmi.com | mscsoftware.com New Parallel Solution for MSC Nastran-PEM Overview
• Nastran/PEM analysis of large models with many trim components expose limitations to Nastran DMP
• Primary use case: automotive model with several trim components, for example • 10 trim components • 20 – 30 trim master frequencies • 15 – 20 panels defined for panel participation
• PEM-related operations computed on Master DMP process only, even in DMP mode • Based on DMP Master-Slave approach • Unacceptable runtime
36 | hexagonmi.com | mscsoftware.com New Parallel Solution for MSC Nastran-PEM Overview
Example compute profile using DMP=2
Step Computation Percent of Total
1 Nastran phase 1 1.0
2 Modal reduction 2.7 Increasing DMP value has no effect on performance 3 Frequency response 0.1
4 Actran 9.6
5 Import RIM 8.0 Serial
6 Acoustic coupling 29.7 processing
7 PPF coupling 46.5 (SMP only)
8 PPF calculation 0.8
9 Other 0.9
37 | hexagonmi.com | mscsoftware.com DMP=2 example • Trim Master Frequencies are evenly Forcing Frequencies (241) Master: 101 from 10-110 distributed to DMP processes Slave: 140 from 111-250 • Corresponding forcing frequencies Trim Master Frequencies (22) may be unbalanced Master: 12 from 10-120 Slave: 12 from 110-260 • This is OK if the cost per forcing frequency is small
38 | hexagonmi.com | mscsoftware.com New Parallel Solution for MSC Nastran-PEM Usage
• REQUIRED: PARAM,PEMDMP,YES in bulk data • User must specify dmp=N (N>1) on command line • If multiple hosts are used, no additional input is required • Specify multiple hosts on command line, for example: host=host1:host2
• If using a single host, specify the RUNOPT keyword on DOMAINSOLVER • DOMAINSOLVER ACMS (RUNOPT=MULTIMST, …)
• When PEMDMP is activated, User Information Messages 10544 and 10545 are printed in F06 file: *** USER INFORMATION MESSAGE 10544 (MTMD62) TOTAL NUMBER OF FORCING FREQUENCIES: 481 - MIN FORCING FREQUENCY: 20.00 - MAX FORCING FREQUENCY: 500.00 TOTAL NUMBER OF TRIM MASTER FREQUENCIES: 25 - MIN TRIM MASTER FREQUENCY: 20.00 - MAX TRIM MASTER FREQUENCY: 500.00
*** USER INFORMATION MESSAGE 10545 (MTMD62) PROCESS ID NUMBER OF TRIM MASTER FREQUENCIES (MIN - MAX) NUMBER OF FORCING FREQUENCIES (MIN - MAX) 1 14 20.00 ( 1) - 280.00 ( 14) 241 20.00 ( 1) - 260.00 ( 241) 2 13 260.00 ( 13) - 500.00 ( 25) 240 261.00 ( 242) - 500.00 ( 481)
39 | hexagonmi.com | mscsoftware.com New Parallel Solution for MSC Nastran-PEM
Example: PEMDMP Test Case from Auto Industry Machine characteristics • Linux RH7.5 Model description • 512GB main memory • 3.4 million grid points; 20.0 million DOF; structure A-size 15.5 million DOF • IntelR XeonR Gold 6126 CPU @ • Eigenvalues: 2400 up to 400Hz (structure) – 300 up to 800Hz (fluid) 2.6.0GHz • 241 forcing frequencies from 10Hz to 250Hz @1Hz • Jobs were run using 200gb memory and 8 cores per DMP process • 9 trim components – 22 trim master frequencies (smp=8). • 17 panels Elapsed Time (hours) Version Elapsed Time Disk I/O Max Disk 25
20 2020.0 DMP=2 1271:34 (21h 11m) 25.0 TB 2.0 TB
15 2021.0 DMP=2 784:09 (13h 4m) 29.4 TB 2.3 TB (14.7TB/host) (1.1TB/host) 10 2021.0 DMP=3 603:22 (10h 3m) 28.6 TB 2.7 TB (9.8TB/host) (0.9TB/host) 5
2021.0 DMP=4 512:37 (8h 32m) 31.0 TB 2.8 TB 0 (7.7TB/host) (0.7TB/host) DMP=2 DMP=2 DMP=3 DMP=4 V2020.0 V2021.0
40 | hexagonmi.com | mscsoftware.com High-Fidelity Tire Modeling with CDTire/NVH
41 | hexagonmi.com | mscsoftware.com High-Fidelity Tire Modeling with CDTire/NVH Overview
Introduction • CDTire is a popular 3-D tire simulation model family used in the automotive industry: • Modelling and parameterization of all functional layers of a modern tire • Accurate modelling acoustic cavity and gyroscopic effects of rolling tire
• CDTire has introduced a linearized tire capability called CDTire/NVH: • The linearized tire matrices are exported around a particular operating condition (tire rotation speed, inflation pressure, preload, contact patch discretization, etc.) of interest to the simulation engineer • Linearized tire matrices and associated model information are exported for direct inclusion in MSC Nastran
42 | hexagonmi.com | mscsoftware.com High-Fidelity Tire Modeling with CDTire/NVH Overview
• MSC Nastran 2021 enables the use of CDTire/NVH tire models in the following solutions: • SOL 103: Normal modes • SOL 107, Sol 110: Direct and Modal Complex modes • SOL 108, 111: Direct and Modal Frequency response • SOL 109, 112: Direct and Modal Transient response • SOL 200 Analysis • SOL 400 Linear
• Typical Applications: • NVH analysis using transient and frequency response simulation • Ride Comfort studies on digitized road surfaces • Harshness analysis on artificial obstacles (cleats)
43 | hexagonmi.com | mscsoftware.com High-Fidelity Tire Modeling with CDTire/NVH Overview
Benefits • Accurate NVH simulation require high fidelity tire models • Particularly with electric cars (eNVH) where road noise is more apparent • Previously MSC Nastran users have employed modal tire model provided by the tire manufacturers - modal tires have a few drawbacks: • Cannot change boundary conditions or operating conditions • Gyroscopic effects and acoustic cavity are not modeled • Tire Models are expensive to generate and automobile manufacturers already use them in their vehicle handling simulations • The same models can now be used for NVH simulations in MSC Nastran
Licensing • Fraunhofer license required for CDTire/NVH • Separate MSC Nastran license feature NA_Tire_Modeling
44 | hexagonmi.com | mscsoftware.com High-Fidelity Tire Modeling with CDTire/NVH Workflow CDTire/NVH Generator Tire model generation • CDTire/NVH tire models consist of two ASCII files meant for direct inclusion in the Nastran input file: • XXX_GRID.dat : Which has the associated tire model information containing GRIDs/SPOINTs, RBE2s, CORD1R and PLOTELs. To position the tire within the vehicle the interface grids (wheel center, Z-Axis and X-Axis grids) need to be repositioned by the user • XXX_DMIG.dat : The linearized tire system matrices, i.e., mass, damping and stiffness matrices. These matrices are exported in Nastran DMIG format
45 | hexagonmi.com | mscsoftware.com High-Fidelity Tire Modeling with CDTire/NVH Workflow
CDTire/NVH Generator creates the linearized CDTire/NVH Tire Model representation of the tire at a particular XXX_GRID.dat: tire model information operating condition XXX_DMIG.dat: linearized tire matrices
MSC Nastran SOL 103, 107/110, NVH analysis model with tire 108/111, 109/112, SOL 200 definition and SOL 400 Linear
46 | hexagonmi.com | mscsoftware.com Coupled Modes Support for External Superelements
47 | hexagonmi.com | mscsoftware.com Coupled Modes Support for External Superelements Overview
Introduction • A coupling surface exists between the solid mesh of a fluid cavity and the structural elements • The vibrating structure defines a velocity boundary condition on the fluid • The acoustic pressure in the fluid defines a pressure load on the structure Structure • Some considerations • A fluid completely enclosed by a structure has a stiffening effect on it Fluid cavity • The inertia of the fluid increases the mass of the structure • For gas cavities, these effects are small and allow uncoupled analysis • For heavy fluids (gasoline, water,…) these effects cannot be ignored • The coupling appears in K and M matrices rendering them asymmetric • External superelements in a dynamic analysis • Component mode synthesis (CMS) is needed to obtain results for the final assembly run • A new capability allows coupled modes to be computed for the CMS phase of the external superelement generation Benefits • Real coupled modes for the CMS also supports ADAMSMNF • Analysis of launch vehicles and tanks filled with heavy fluid, i.e. liquids
48 | hexagonmi.com | mscsoftware.com Coupled Modes Support for External Superelements Usage Acoustic pressure at point id =158721 3.00E-05
• EXTSE creation with coupled modes. 2.50E-05
2.00E-05 • Standard EXTSEOUT case control format • METHOD(COUPLED) = setid 1.50E-05
• SDAMPING(COUPLED) = tabid 1.00E-05
• Bulk Card entry Displacement 5.00E-06 • EIGR/EIGRL with V1,V2,ND 0.00E+00 • PARAM,SESDAMP, AUG (recommended) – 1.00E+01 2.00E+01 3.00E+01 4.00E+01 5.00E+01 6.00E+01 7.00E+01 for SDAMPING(coupled) -5.00E-06 • Standard TABDMP1 -1.00E-05 Freq • ASETi/BSETi/ACCSSPT (fixed boundary) oil_tank_SE108 oil_tank_noSE108
49 | hexagonmi.com | mscsoftware.com External Superelements with Monitor Points
50 | hexagonmi.com | mscsoftware.com External Superelements with Monitor Points Overview
Introduction • Enhancement combines two powerful capabilities • External superelements • Monitor points • For example: • A subcontractor can define monitor points in an external superelement • The general contractor can compute the monitor point responses in the assembly run
Usage • No new Case Control or Bulk Data entries required • In the external superelement creation run the user specifies: • MONITOR and EXTSEOUT Case Control commands • Bulk Data entries: MONDSP1, MONPNT1, MONPNT2, MONPNT3, MONSUM, MONSUMT and MONSUM1 • In the assembly run the user needs to specify the MONITOR Case Control command to obtain the monitor point results for the external superelement
51 | hexagonmi.com | mscsoftware.com External Superelements with Monitor Points Example
• Simulated Rocket Example • Simple Cylinder 10 units long comprises the external superelement 55 • Boundary grids form the residual structure and are located at every 2.5 units along centerline and connected by rigid spiders (5 stations at 0.0, 2.5, 5.0, 7.5, 10.0 units)
• Generation of MONPNT3 input for Section Loads using Patran Flight Loads option • Select “MonPt” location (node at centerline) • Select Nodes for section cut • Select elements on one side of section cut
52 | hexagonmi.com | mscsoftware.com External Superelements with Monitor Points Example
• Assembly run f06 excerpt showing station cut loads at 2.5 units for external superelement 55 • Monitor point results are also written to op2 and hdf5 if requested SUPERELEMENT 55
S T R U C T U R A L I N T E G R A T E D F R E E B O D Y M O N I T O R P O I N T L O A D S (MONPNT3)
MONITOR POINT NAME = STA2.5 SUBCASE NO. 1 LABEL = STATION 2.5 SECTION LOADS CP = 0 X = 2.50000E+00 Y = 0.00000E+00 Z = 0.00000E+00 CD = 0
AXIS REST. APPLIED AXIS REST. APPLIED ------CX -2.089855E-06 CX -2.090819E-06 CY 5.765389E-03 CY 5.765406E-03 CZ -3.563133E-03 CZ -3.563134E-03 Internal Superelement Results CMX 5.340617E-03 CMX 5.340590E-03 CMY -4.973561E-03 CMY -4.973563E-03 CMZ -8.129106E-03 CMZ -8.129109E-03
53 | hexagonmi.com | mscsoftware.com Bent Rotor Modeling in Rotordynamics
54 | hexagonmi.com | mscsoftware.com Bent Rotor Modeling in Rotordynamics Overview
Introduction • In reality, there are imperfections, manufacturing tolerances, that cause rotor geometry to be susceptible to bends, kinks and offsets • MSC Nastran 2021 introduces a new feature to model the imperfect geometry of a rotor • New ROTBENT Case Control command and Bulk Data entry in SOL 400 • Current implementation is for line rotors (1D line elements) modeled as 3D rotors using the ROTOR entry
Workflow – two steps in SOL 400 • Step 1 – static analysis • Model the rotor as straight • Use ROTBENT bulk data entry to model the imperfections (kinks and offsets) and bearing connections • MSC Nastran will update the rotor geometry effectively pulling the rotor into the bearings and making the connection • Step 2 – complex eigenvalue analysis or frequency response using the solution of Step 1 as a starting point • Complex eigenvalues includes Campbell diagrams • Frequency response includes dynamic application of the forces due to pulling the rotor into the bearings
55 | hexagonmi.com | mscsoftware.com Bent Rotor Modeling in Rotordynamics Example – Executive and Case Control
SOL 400 CEND RIGID=LINEAR $ optional rotbent=1 SPC = 10 $ SPC’s holding stator to ground (The ROTBENT will create SPC’s, MPC’s, and SPCD’s pulling the rotor into the bearings) subcase 1 step 1 $ static solution to pull rotor into bearings nlparm=1 analysis=nlstat $ first step is the static solution load = 1 $ point to LOAD ID on ROTBENT in bulk data for static loads pulling rotor into bearings step 2 $ Rotordynamics solution label = complex eigenvalues $ can be complex modes or frequency response ANALYSIS=dceig cmethod = 1 RGYRO= 100 NLIC = 1 $ use results of STEP 1 as the starting point
56 | hexagonmi.com | mscsoftware.com Bent Rotor Modeling in Rotordynamics Example – Bulk Data
For this example, let us assume we have a rotor which is parallel to the BASIC X axis and we wish the ROTOR Y-axis to be parallel to the BASIC Y (Rotor system parallel to basic system)
Bulk data Input (For this example, all GRID points use BASIC as CD): rotbent,1,10,3 $ ROTBENT 1, for ROTOR 10, creates loads for LOAD=3 ,unbcord,0. ,1.,0. $ rotor XY plane – in the CD of the first GRID on the AXIS list ,offset,1.1,.1,0. ,,2.1,.2,90. ,,3.1,.3,180. ,brgdpr,1,101 $ bearing pairs: rotor grid to stator grid ,,10,110
57 | hexagonmi.com | mscsoftware.com Bent Rotor Modeling in Rotordynamics Example
K&O After Pulling into Bearings 0.002 0.0025
0 0.002 -0.002 T2 0.0015 T1 T3 -0.004 BRG 0.001 T3 -0.006 BRG 0.0005 -0.008 0 -0.01
-0.0005 Deformation,in Deformation,in -0.012 -0.001 -0.014
-0.016 -0.0015
-0.018 -0.002
-0.02 -0.0025 0 10 20 30 40 50 60 0 10 20 30 40 50 60 Axis, in Axis, in
58 | hexagonmi.com | mscsoftware.com Bent Rotor Modeling in Rotordynamics Example
Unbalance Response with Kinks and Offsets Response - Kink&Offset Only 0.0035 0.000008
0.003 0.000007 Node 4 Node 4 0.000006 0.0025 Node 15 Node 15 0.000005 0.002 0.000004 0.0015
0.000003
Amplitude,in Amplitude,in 0.001 0.000002
0.0005 0.000001
0 0 0.0 50.0 100.0 150.0 200.0 250.0 300.0 350.0 0.0 50.0 100.0 150.0 200.0 250.0 300.0 350.0 Freq, Hz Freq, Hz
59 | hexagonmi.com | mscsoftware.com Fatigue: CAEfatigue in MSC Nastran
60 | hexagonmi.com | mscsoftware.com CAEfatigue Software (Cf) Updating current NEF and NEVF over 3 release cycles through June 2021 3 Software Packages 4 Technologies For Fatigue, Random Response, Loads Management and Test Design
Frequency Premium Test
Premium Full Body Time 61 | hexagonmi.com | mscsoftware.com CAEfatigue Software (Cf) The Vision for Alignment with MSC Software / Hexagon
One unified Durability, Random Response and Loads Management offering
Cf Cf Cf TIME FREQUENCY PREMIUM
Solver Linked MSC One Apex Aligned (Nastran, Marc) Supports Nastran, Optistruct, Ansys, Abaqus
62 | hexagonmi.com | mscsoftware.com CAEfatigue in MSC Nastran Roadmap through mid-2021
• MSC Nastran 2021 (December 2020) • All Time Domain updated except items listed on next slide • MSC One licensing added to both Time Domain (NEF) and Frequency Domain (NEVF) solvers • CAEfatigue is now the default NEF and NEVF technology
• MSC Nastran 2021.1 (March 2021) • Time Domain update will be completed
• MSC Nastran 2021.2 (June 2021) • Frequency Domain update will be completed with the addition of a “Random” solver (MSC Random inside Nastran!)
63 | hexagonmi.com | mscsoftware.com CAEfatigue in MSC Nastran CAEfatigue Limitations in MSC Nastran 2021 Case or Bulk Data Non-Supported Entries
FATIGUE FORMAT=1,2,4,16, 32 or any bit combination that contains these values STROUT=4 HISTOGRAM Just the existence
FTGDEF TOPSTR TOPDMG SPOTW or SEAMW {of any kind} FTGPARM PLAST=SEEGER INTERP RAINFLOW FOS DAMAGE SPOTW or SEAMW MULTI COMB=VONMIS,MAXPRINC,SGMAXSHR,MAXSH,COMPX/Y/Z/XY/YZ/ZX CORR=FKM,INTERP FTGSEQ METHOD=1 or 2, nested FTGSEQ
PFTG Non default
MATFTG STATIC CODE>=200, RR != default SN MSS BASTEN TABLE - more than one! 64 | hexagonmi.com | mscsoftware.com TABLRPC The existence of TABLRPC CAEfatigue in MSC Nastran Performance Improvements
• Great strides continue to be made in improvements to Nastran Embedded Fatigue (NEF) time-based fatigue analysis performance.
• In the previous release, performance improvements to fatigue analysis using SOL 112 (modal transient analysis) with load sequences using multiple events (Duty Cycles) was introduced
• In this release, more algorithm improvements have been made (by incorporating CAEfatigue technology) to speed up all time-based fatigue analyses using SOL 101, 103, and 112. • The magnitude of the performance increase is dependent on the complexity of the analysis, favoring large models with complex and long loading histories, such as the road load data used for typical automotive vehicle duty cycles
65 | hexagonmi.com | mscsoftware.com CAEfatigue in MSC Nastran Performance Improvements
• The performance improvements are applicable to standard S-N and e-N analysis • Improvements to other fatigue analysis types such as Spot Weld, Seam Weld, Factor of Safety, Multi-axial Assessment, 3-pass (hot spot) and frequency domain are planned for future releases
66 | hexagonmi.com | mscsoftware.com CAEfatigue in MSC Nastran Performance Improvements
67 | hexagonmi.com | mscsoftware.com Nonlinear SOL 400
68 | hexagonmi.com | mscsoftware.com Brake Squeal Enhancements
69 | hexagonmi.com | mscsoftware.com Brake Squeal Enhancements Overview
Introduction • Brake squeal is induced from the sliding friction contact between the rotating disk and static pads • Also influences the deformation of the brake system and other parts of the structure
Limitations of current capability • Multiple wheels / axes are not supported • Can’t specify brake / disk pair – all touching contact pairs are treated as part of the brake • Drum brakes not supported • Disk rotation effects are not included
70 | hexagonmi.com | mscsoftware.com Brake Squeal Enhancements Overview
Benefits • In MSC Nastran 2021 all previous limitations are removed • NLSTAT enhanced to include disk rotation effect • Multiple wheels / axes supported • Drum brakes supported • Explicitly define brake contact pairs • Translational movement definition added • Supporting users to determine the touching contact status during the linear perturbation and ignoring the status obtained by nonlinear static analysis
71 | hexagonmi.com | mscsoftware.com Brake Squeal Enhancements Example Disk (Rotor) • Model • (brksys5a wo sliding) Pads • (brksys3a w sliding)
Pistons
72 | hexagonmi.com | mscsoftware.com Brake Squeal Enhancements Example: Friction force
Disk No Sliding Disk Sliding
73 | hexagonmi.com | mscsoftware.com Brake Squeal Enhancements Example: Eigenvalue Output
Disk No Sliding
Disk Sliding
74 | hexagonmi.com | mscsoftware.com Brake Squeal Enhancements Example: Eigenvectors 1st mode 2nd mode
No Sliding
Sliding
75 | hexagonmi.com | mscsoftware.com Brake Squeal Enhancements Other Applications
Squeal analysis of windshield wipers Translation movement in motion squeal analysis and general contact analysis
76 | hexagonmi.com | mscsoftware.com Segment-to-Segment Contact Enhancements
77 | hexagonmi.com | mscsoftware.com Segment-to-Segment Contact Enhancements Overview
Feedback • Node-to-seg converges, but seg-to-seg doesn’t • Seg-to-seg in Marc converges, but SOL 400 doesn’t • SOL 400 requires more iterations than Marc • Seg-to-seg is unstable in different releases
Objective with MSC Nastran 2021 • Improve seg-to-seg robustness • Improve consistency compared with Marc
Implementation • Change default settings in seg-to-seg contact • Activate enhanced algorithm from contact component in Marc
78 | hexagonmi.com | mscsoftware.com Segment-to-Segment Contact Enhancements Enhancement
List of enhanced items to improve performance and robustness of seg-to-seg method
• Ramping down penalty when angle between segment normals below minimum segment angle
• Evaluate contact matrix/force based upon true updated patch coordinates
• New patch sequence renumbering algorithm based upon patch geometry
• Reset iteration count after separation
• New logic in creating polygons under sliding condition
• Scaled incremental displacement update in large rotation scheme
79 | hexagonmi.com | mscsoftware.com Segment-to-Segment Contact Enhancements Usage
BCPARA 0 METHOD SEGTOSEG VERSION 1 OR 2 BACKCTL 0 TO 63
VERSION Defaults version control in Segment-to-Segment method
1 Version 1
2 (default) Version 2 (lower penalty, recommended)
BACKCTL Backward compatible bit-wise control in seg-to-seg contact analysis (0 default)
1 Body order independent and ramping down penalty below minimum seg angle
2 Old evaluation of contact matrix/force on patch coordinates (back to 2020 SP1)
4 Old patch sequence renumbering (back to 2020 SP1)
8 No reset iteration count after separation (back to 2020 SP1, Version 2 only)
16 Old logic in creating new polygons (back to 2020 SP1)
32 Scaled incremental displacement update in small rotation (back to 2020 SP1)
80 | hexagonmi.com | mscsoftware.com Segment-to-Segment Contact Enhancements Example Benchmark
158,600 NODEs 101,970 TETRAs
2 Bolts 5 Contact Bodies
9 STEPs mechanical+thermal load 3 increments for 1st and 2nd STEP 1 increment for the rest STEPs
CONV=PV EPSP=5.0E-2
Nastran 2020 (Version 2) Total Iteration 270
Nastran 2021 beta (Version 2) Total Iteration 88
Nastran 2021 beta (Version 1) Total Iteration 112
Nastran 2021 beta (Version 2) Total Iteration 103 1 increment for all 9 STEPs CONV=PV EPSP=1.0E-2
81 | hexagonmi.com | mscsoftware.com ESE and EKE in SOL 400 Multi- disciplinary and Linear Perturbation Analyses
82 | hexagonmi.com | mscsoftware.com ESE and EKE in SOL 400 Overview
Introduction • Element Strain Energy (ESE) and Element Kinetic Energy (EKE) computations have been traditionally supported for linear Nastran elements in linear analyses such as static, transient and modal analyses • Users have requested ESE and EKE support in Nastran SOL 400 linear perturbation analysis using normal modes (MODES) and modal complex eigenvalue (MCEIG) analyses • This release introduces ESE and EKE support in Nastran SOL 400 multi-disciplinary and linear perturbation analyses using MODES and MCEIG analyses and includes support for advanced nonlinear elements
Benefits • Strain energy density gives analysts insight into the regions in the model that have the greatest deformation • Strain energy density is a very good indicator for load paths, fracture, damage and fatigue prediction; elements located on a load path work harder than others • Topology optimization may involve an evaluation of the strain energy density for several modes then removing material from regions with low strain energy density and adding material to regions of high strain energy density • Kinetic energy density can help locate where to place dynamic vibration absorbers in a structure; vibration absorbers are typically placed in regions with high kinetic energy density • ESE and EKE computations in modal analyses also reveal the modal energy contributions of a particular mode
83 | hexagonmi.com | mscsoftware.com ESE and EKE in SOL 400 Overview
Usage • Existing Case Control commands are used to request ESE and EKE output in SOL 400 multi-disciplinary and linear perturbation analyses • User can select ALL elements or a subset of elements for output • Output includes element strain / kinetic energy, element strain / kinetic energy density and percent of model total • For modal complex eigenvalue analysis, AVERAGE, AMPLITUDE and PEAK values of ESE and EKE are supported, AVERAGE is the default • Results may be output to the F06, OP2 and/or H5 files for the selected elements for each mode
84 | hexagonmi.com | mscsoftware.com HPC: MUMPS Solver in Linear Statics
85 | hexagonmi.com | mscsoftware.com MUMPS Solver in Linear Statics Overview
Introduction • Solution of linear equations comprises more than 60% of the elapsed time in SOL 101 • Problem size ranges from 10M to 50M dof and extending to 300M dof in the future • Multi-frontal direct solvers (like MUMPS) require 5x-7x higher memory than frontal direct and iterative solvers • Need for distributed memory direct solver in MSC Nastran
Benefits • Less memory required per machine / host via DMP compared to MKL Pardiso • Scale out capability across multiple machines / hosts
Current limitations • Inertia relief -1, -2 is not supported • SOL 101 jobs involving linear contact is not supported • Only in-core is supported • Windows platform is not supported
86 | hexagonmi.com | mscsoftware.com MUMPS Solver in Linear Statics Usage
Input • Invoke MUMPS Solver by using the SPARSESOLVER executive control statement • Only DCMP module of SPARSESOLVER statement is supported.
SOL 101 SPARSESOLVER DCMP(FACTMETH=mumps) CEND
Output in F04
87 | hexagonmi.com | mscsoftware.com MUMPS Solver in Linear Statics Performance Results
Solver Performance Comparison
300 274
250
200 172
50m dof (shell elements) 150 Pardiso 100 Mumps
Elapsed time inminutes timeElapsed 43 39 44 50 30 33 35 27
0
• MUMPS scalability slightly better in most of the above configurations • DMP=4 and SMP=8, MKL Pardiso’s in-core memory requirement is higher than available physical memory on the machines, whereas MUMPS ran successfully and showed further scalability on the same machines because of its lower memory requirement per machine/host
88 | hexagonmi.com | mscsoftware.com Results: Eigenvector Output with Lossy Compression
89 | hexagonmi.com | mscsoftware.com Eigenvector Output with Lossy Compression Overview
Introduction • New lossy compression support in MSC Nastran 2021 • NLOUT output • Monitor point output • Included support for more data types • Brake squeal, temperature dependent entries, GPFORCE, PACCELERATION
Benefits • Improve NH5RDB performance • Store data more efficiently • Enhanced data structures improve post-processing applications (indexing)
90 | hexagonmi.com | mscsoftware.com NH5RDB Compression in NH5RDB
• Current compression – Gzip compressor • Lossless compression • Applied to compound data – Tables • All datasets in current NH5RDB are defined as compound types • Data structure with integers, characters and floating-point numbers
• New lossy compression support – Scaleoffset Compressor • Applied on matrix • Floating-point numbers only • Support multiple dimensional array • Define floating point number array type dataset
91 | hexagonmi.com | mscsoftware.com NH5RDB NH5RDB Schema Update
• NH5RDB schema is extended to support lossy compression definition • Add scaleoffset attribute for lossy compression definition • Support compression factor option in model • Add MDLPRM parameters for compression option in input file • For example, use factor 3 (default) for defined dataset with scaleoffset compressor: MDLPRM, H5SGENL,3 • Factor ranges from -1 to 10 • 0 to 10 : scale factor with lossy compression • -1: Use lossless compression Compression Dataset Compression Example: Method Size (MB) Ratio • Eigenvector matrix output Scaleoffset, factor = 3 129 4.75 • DOF number = 220,698, Eigenvector number = 364 Scaleoffset, factor = 4 160 3.84 • Matrix data size: 220,698 x 364 x 8 = 612 MB Scaleoffset, factor = 5 190 3.22 • Run with different factors for lossy compression Scaleoffset, factor = 6 221 2.77 and lossless compression Gzip, level = 1 584 1.05
92 | hexagonmi.com | mscsoftware.com SOL 700 / Dytran: DMP Support for Lagrangian Solver
93 | hexagonmi.com | mscsoftware.com Distributed Memory Parallel (DMP) for Structural Solver in SOL 700 Overview
Introduction • DMP was already implemented for the Eulerian (fluid) solver • MSC Nastran 2021 introduces the DMP for the Lagrangian (structural) solver
Cores Performance 1 1.00 2 2.05 4 4.01 8 7.27 16 11.25 32 17.64
Benefits • Performance improvements for large models on machines with multiple cores and/or clusters of multiple nodes • Initial focus is on quality, subsequent releases will optimize MPI calls and load balancing
94 | hexagonmi.com | mscsoftware.com Distributed Memory Parallel (DMP) for Structural Solver in SOL 700 Usage
• Any explicit model with a large number of structural elements
• Limitations: • Contact serial only under DMP run • Rigid bodies and rigid connections are calculated in the Master CPU only under DMP run • Contact options BELT/BELT1/DRAWBEAD not supported • Older Contact Version 2 not supported • ATB dummies not supported • IMM (Initial Metric Method) for air bag simulations not supported • Nastran prestress
• Control DMP with DYPARAM, DMPOPT: • FSI DMP but not Structure • Structure DMP but not FSI • FSI and Structure DMP
95 | hexagonmi.com | mscsoftware.com Distributed Memory Parallel (DMP) for Structural Solver in SOL 700 Further Details
• Performance improvements are especially expected under the following circumstances when the serial has:
1. High elapsed time per cycle: Time/Cycle > 0.1 seconds 2. No or low contact (contact is running serial) 3. At least 2,000 elements per core (performance gains outweighing MPI communications) 4. Low number of properties and element types (load balancing and MPI call optimizations is work in progress)
96 | hexagonmi.com | mscsoftware.com Distributed Memory Parallel (DMP) for Structural Solver in SOL 700 Performance
• Example 1: Cores Performance 1 1.00 535,416 solid elements 2 1.97 4 3.62 Contact in Serial: 0.28% 8 6.25 16 9.22 Time per cycle: 0.178 seconds 32 12.89
• Example 2: Cores Performance 1 1.00 2 1.93 165,000 solid / shell elements 4 3.33 Contact in Serial: 2.4% 8 5.41 16 7.23 Time per cycle: 0.06 seconds 32 9.43
97 | hexagonmi.com | mscsoftware.com Thank You!
98 | hexagonmi.com | mscsoftware.com