TABLE OF CONTENTS - EMITS Invitation To Tender...

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THALES ALENIA SPACE INTERNAL

This document is not to be reproduced, modified, adapted, published, translated in any material form in whole or in part nor disclosed to any third party without the prior written permission of Thales Alenia Space.

2013, Thales Alenia Space Template 83230326-DOC-TAS-EN/002

CHANGE RECORDS

ISSUE DATE § CHANGE RECORDS AUTHOR

01 27/02/2013 First issue M. Migliaccio

02 30/10/2013 Issue to close action relevant SRR RID RS-40.

Chapter 4.2.5. updated.

M. Migliaccio

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TABLE OF CONTENTS

1. INTRODUCTION .................................................................................................................. 6

2. DOCUMENTS....................................................................................................................... 6

2.1 APPLICABLE DOCUMENTS .....................................................................................................................6

2.2 REFERENCE DOCUMENTS AND DRAWINGS........................................................................................6

3. CODES ................................................................................................................................. 6

4. NASTRAN FEM REQUIREMENTS...................................................................................... 7

4.1 UNIT SYSTEM ............................................................................................................................................7

4.2 GENERAL REQUIREMENTS.....................................................................................................................7 4.2.1 CO-ORDINATE SYSTEMS.....................................................................................................................8

4.2.1.1 MATERIAL ORIENTATION............................................................................................................9 4.2.2 SPECIFIC ANALYSIS REQUIREMENTS...............................................................................................9 4.2.3 MODEL SIZE ..........................................................................................................................................9

4.2.3.1 NUMBERING RANGES ...............................................................................................................10 4.2.4 NODE DEFINITION ..............................................................................................................................10 4.2.5 CELAS ELEMENTS..............................................................................................................................11 4.2.6 MPC ELEMENTS..................................................................................................................................11 4.2.7 NON STRUCTURAL AND LUMPED MASSES ....................................................................................11 4.2.8 SUPER-ELEMENT TECHNIQUE .........................................................................................................11

4.3 INTERFACE REQUIREMENTS................................................................................................................11

4.4 REDUCED MODEL REQUIREMENTS.....................................................................................................12 4.4.1 REDUCTION TECHNIQUES ................................................................................................................12 4.4.2 MINIMUM NODE SET...........................................................................................................................12

5. FEM MODEL QUALITY ASSURANCE .............................................................................. 13

5.1 INTRODUCTION.......................................................................................................................................13

5.2 PRE-RUN CHECKS..................................................................................................................................13

5.3 POST-RUN CHECKS ...............................................................................................................................14 5.3.1 NASTRAN OUTPUT FILES ..................................................................................................................14 5.3.2 GRAVITY LOAD CHECK......................................................................................................................15 5.3.3 STRAIN ENERGY CHECK ...................................................................................................................15 5.3.4 RIGID-BODY FREQUENCY CHECK ...................................................................................................15 5.3.5 NORMAL MODE ANALYSIS ................................................................................................................15 5.3.6 THERMO-ELASTIC CHECK.................................................................................................................16 5.3.7 CB REDUCED MODEL CHECKS ........................................................................................................16

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6. MODEL VALIDATION (PHASE C/D ONLY) ...................................................................... 18

6.1 STATIC MODEL........................................................................................................................................18

6.2 DYNAMIC MODEL....................................................................................................................................18

7. DELIVERABLES ................................................................................................................ 19

7.1 DELIVERABLE FEM ITEM LIST..............................................................................................................19

7.2 FEM MODEL FILES REQUIREMENTS....................................................................................................19 7.2.1 NASTRAN INPUT FILES ......................................................................................................................19 7.2.2 NASTRAN BULK DATA........................................................................................................................20

7.2.2.1 NASTRAN BULK DATA FILE ORGANISATION..........................................................................20 7.2.2.2 NASTRAN BULK DATA COMMENTS .........................................................................................21

7.2.3 NASTRAN MATRICES .........................................................................................................................21 7.2.4 ANALYSIS RESULTS...........................................................................................................................22

7.3 DATA AND INFORMATION EXCHANGE................................................................................................23

8. MATHEMATICAL MODEL DESCRIPTION (MMD)............................................................ 24

8.1 CONTENTS...............................................................................................................................................24

8.2 REQUIREMENTS......................................................................................................................................26

ANNEX 1 ................................................................................................................................... 27

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LIST OF ACRONYMS

ASCII American national Standard Code for Information Interchange ATM Acceleration Transformation Matrix CB Craig-Bampton CBAR NASTRAN simple BAR element CELAS2 NASTRAN ELAStic element, form 2 CQUAD4 NASTRAN QUADrilateral plate element with 4 grids CONM2 NASTRAN CONcentrated Mass element, form 2 CoM Centre of Mass DMAP Direct Matrix Abstract Programming DOF Degree Of Freedom DTM Displacement Transformation Matrix ESS Electronic Support Structure FEM Finite Elements Method FTP File Transfer Protocol GRID NASTRAN Geometric GRID point ID IDentification I/F InterFace LTM1,2 Load Transformation Matrix MAC Modal Assurance Criterion MMD Mathematical Model Description MMDD Mathematical Model Delivery Document MSC MacNeal-Schwendler Corporation MPC NASTRAN Multi-Point Constraint NASTRAN NASA STRuctural ANalysis NSM Non Structural Mass OTM Output Transformation Matrix PBAR NASTRAN simple BAR Property PFM ProtoFlight Model PSHELL NASTRAN SHELL element Property RBE2 NASTRAN Rigid Body Element form 2 RBE3 NASTRAN Rigid Body Element form 3 RDA Radar Doppler Assembly SDRC Structural Dynamics Research Corporation SESET NASTRAN SuperElement SET SPC NASTRAN Single-Point Constraint STM STructural Model TEMPD NASTRAN Default TEMPerature

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1. INTRODUCTION

This document defines the general requirements for the preparation and delivery to the ExoMars program mission 2018 of the following FEM models:

Carrier Module Descent Module Parachute RDA Rover Vehicle ALD FEM models (to be used in the integrated system analyses); DRILL FEM models (to be used in the integrated system analyses); Payloads and Units FEM’s Any non-conformance shall be submitted to EXOMARS System for request of approval. The application of the requirements specified herein will allow full compatibility, integration and homogeneous quality of the different models and consequently correct analysis/verification activities at system level.

2. DOCUMENTS

2.1 APPLICABLE DOCUMENTS

None.

2.2 REFERENCE DOCUMENTS AND DRAWINGS

None.

3. CODES

a. All the FEM models shall be fully compatible with MSC/NASTRAN version 2008 upwards. b. Pre/post-processors adopted by TAS-I are: FEMAP 9.0 upwards. MSC PATRAN 2005 upwards. ALTAIR HYPERMESH 8.0 upwards.

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4. NASTRAN FEM REQUIREMENTS

4.1 UNIT SYSTEM All FEM models shall be established with International System of measurement units (metre, kilogram, second, Newton, radian, Celsius degree). All data reported in the present document have to be intended in SI, if not otherwise specified.

4.2 GENERAL REQUIREMENTS

a. All mathematical models shall be linear; use of non-linearity will require prior approval.

b. In any case if non-linearity is present they shall be highlighted.

c. All elastic elements shall have linear order. d. PARAM AUTOSPC YES should not be used; if used, the developer shall explain all

DOFs blocked by the AUTOSPC. e. PARAM K6ROT should not be used; if used, the developer shall justify it. As a minimum

sensitivity analyses should be performed in order to demonstrate that the analysis results are not sensitive to this parameter (e.g.: a normal mode analysis/stress/force/etc. with tree different values of K6ROT (1, 100, 10000) should not affect significantly the results (frequency shift and modal mass of paired modes ≤ 0.1% compared to baseline value is considered acceptable).

f. Any other data cards affecting other sub-models when merged (e.g. GRDSET, BAROR,

BAILOUT, MAXRATIO etc.) shall be avoided.

g. PARAM, SNORM, 20 may be used. h. Models, developed to be subjected to thermo-elastic and moisture release analyses

(either as stand-alone sub-model or merged in the overall S/C model), shall not include rigid regions which may prevent elongation.

i. The definition of elements, co-ordinate systems and load orientation in the space shall be

made using vector components technique rather than grid points technique (e.g.: use cards CORD2C/R/S instead of CORD1C/R/S).

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4.2.1 CO-ORDINATE SYSTEMS

a. The FEM primary co-ordinate system for all FEM Models shall be defined by the supplier. b. Geometry and further auxiliary local co-ordinate systems (if any) shall be defined with

respect to their FEM primary co-ordinate system. In particular: if rectangular co-ordinate systems are used, they shall be referred to the FEM primary co-

ordinate system and shall have, as long as possible, their X, Y and Z axes aligned with the FEM primary co-ordinate system X, Y and Z axes.

if cylindrical co-ordinate systems are used, they shall be referred to the FEM primary co-ordinate system and shall have, as long as possible, their z-axis aligned with the FEM primary co-ordinate system X-axis, and their r-axis aligned with the FEM primary co-ordinate system Y-axis.

if spherical co-ordinate systems are used, they shall be referred to the FEM primary co-ordinate system and shall have, as long as possible, their r-axis aligned with the FEM primary co-ordinate system X-axis.

Each local co-ordinate system shall be referred to the local co-ordinate system of the item to which it is attached.

c. Cylindrical co-ordinate systems shall be used for cylindrical geometry. Spherical co-ordinate

systems shall be used for spherical geometry. d. Geometric relationships between any local auxiliary co-ordinate system and the FEM models

co-ordinate systems and between the latter and the NASTRAN basic co-ordinate system, CS0, shall be clearly identified and described via suitable sketches and/or FEM model plots.

e. In order to simplify the management of the FEM models due to any further possible

modification in the position of the various items of the Spacecraft, the origin of the local co-ordinate systems shall be placed within the physical envelope of each item.

This approach allows an easy integration of each FEM and thus an easier FEM model management at system level.

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4.2.1.1 MATERIAL ORIENTATION

All material orientation angles shall be defined using local co-ordinate system(s). The definition of the material orientation angles with respect to element geometry shall be avoided (distorted elements can introduce mistakes in the material orientation angle definition, while the local co-ordinate system can allow a precise definition of the material orientation angle).

4.2.2 SPECIFIC ANALYSIS REQUIREMENTS

a. The FEM shall adequately define the dynamic behaviour of the structure in the frequency range specified for the single item.

b. All items having pointing stability requirements shall be represented at least by one GRID.

c. Fluid modeling shall be implemented in EXOMARS FEM, if applicable. d. Standard MSC/NASTRAN procedures shall be used as much as possible.

4.2.3 MODEL SIZE

a. Model sizing and application of substructure techniques is left to industrial experience. Nevertheless the subcontractor shall establish FEM models detailed enough to fully analyse and design structural elements.

b. Model shall be a full one: no symmetry assumptions to reduce size are allowed. c. The minimum numbers of GRID points of all the FEM models shall be such that the

maximum distance between two adjacent GRIDs is less or equal to 0.1 metre. This minimum distance is not stringent for special cases, e.g. lump masses connected via RBE elements.

d. The maximum number of all the GRID points of the Exomars 2018 Spacecraft FEM models

shall be as per table 4.2.3.1-1. e. The equipments with mass bigger than 0.1 kg and C.o.M. offset from the supporting

structure higher than 10 mm shall be modelled with lumped masses. Items as per table 4.2.3.1-1 require proper physical FEM detailed modelizations.

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4.2.3.1 NUMBERING RANGES

Identification numbers of all NASTRAN cards shall be included within the ranges summarised in the following table (free ranges are reserved for possible future use):

ITEM S UB ‐ITEM

S PC s , S E Ts

C OORDINATE

S Y S TEM

NODE S , E L EMENTSPROPE RTIE S ,

MATE R IAL S

MAX NUMBE R

OF NODE S AND

E L EMENTS PE R

S UB ‐ITEM

MAX NUMBE R

OF NODE S AND

E L EMENTS

PE R ITEM

C ARR IE R MODUL E 1000001 ‐ 1099999 1000001‐1099999 1000001‐1099999 12000 12000

DE S C E NT MODUL E 1100001 ‐ 1199999 1100001‐1199999 1100001‐1199999 25000 25000

PARAC HUTE 1200001 ‐ 1299999 1200001‐1299999 1200001‐1299999 5000 5000

RDA 1300001 ‐ 1399999 1300001 ‐ 1399999 1300001 ‐ 1399999 500 500

VE HIC LE 500001 ‐ 699999 500001 ‐ 699999 500001 ‐ 699999 20000

PANC AM OPT IC AL BENC H 700001 ‐ 709999 700001 ‐ 709999 700001 ‐ 709999 200

WIS DOM ANTE NNA 800001 ‐ 809999 800001 ‐ 809999 800001 ‐ 809999 200WIS DOM E U 850001 ‐ 859999 850001 ‐ 859999 850001 ‐ 859999 200

S TR UC TUR E 100001 ‐ 199999 100001 ‐ 199999 100001 ‐ 199999 5000

S PDS ‐ C S HS 200001 ‐ 209999 200001 ‐ 209999 200001 ‐ 209999 200

S PDS ‐ C R US HING S TAT ION 210001 ‐ 219999 210001 ‐ 219999 210001 ‐ 219999 200

S PDS ‐ P S DDS 220001 ‐ 229999 220001 ‐ 229999 220001 ‐ 229999 200

S P S DS ‐ C AROUS E L 230001 ‐ 239999 230001 ‐ 239999 230001 ‐ 239999 200

MIRU 250001 ‐ 259999 250001 ‐ 259999 250001 ‐ 259999 200

MOMA LDMS 260001 ‐ 269999 260001 ‐ 269999 260001 ‐ 269999 200

MOMA GC 270001 ‐ 279999 270001 ‐ 279999 270001 ‐ 279999 200

MOMA LAS E R E U 280001 ‐ 289999 280001 ‐ 289999 280001 ‐ 289999 200

MOMA EU 290001 ‐ 299999 290001 ‐ 299999 290001 ‐ 299999 200

R AMAN S PU 300001 ‐ 309999 300001 ‐ 309999 300001 ‐ 309999 200

R AMAN OPT IC AL HE AD 310001 ‐ 319999 310001 ‐ 319999 310001 ‐ 319999 200

R AMAN IC E U 320001 ‐ 329999 320001 ‐ 329999 320001 ‐ 329999 200DR IL L S PDS E U 330001 ‐ 339999 330001 ‐ 339999 330001 ‐ 339999 200

C L UP I 340001 ‐ 349999 340001 ‐ 349999 340001 ‐ 349999 200 200

DR IL L DR IL L + MAMIS S MS B 400001 ‐ 409999 400001 ‐ 409999 400001 ‐ 409999 2000 2000

ROVE R VE HIC L E

ANAL YTIC AL

L ABORATORY

DRAWE R

7600

20600

E XOMARS 2018 S PAC E C RAFT F EM NUMBE R ING RANGE S

Table 4.2.3.1-1 Models items numbering

The EID (Element IDentification number) or PID (Property IDentification number) shall be unique in the FEMs (e.g. for example a CBAR and a CQUAD4 shall not have the same EID).

4.2.4 NODE DEFINITION

a. No nodes of FEM Models shall be referred to the NASTRAN basic co-ordinate system, CS0.

b. In order to avoid numerical rounding problems when merging different models, GRID definition co-ordinates shall be either truncated at the fourth decimal place maximum, or expressed in double precision.

c. Nodes not used shall be removed. d. No permanent single-point constrain shall be used (PS in the GRID card).

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4.2.5 CELAS ELEMENTS

a. They shall connect coincident Grids only. b. Both end GRIDs of any CELAS element shall have the same CD (identification number of

co-ordinate system in which the displacements, degrees of freedom, constraints and solution vectors are defined at the GRID point). The displacement co-ordinate system shall be clearly evidenced.

4.2.6 MPC ELEMENTS

a. MPC elements are forbidden between not coincident nodes (only in the case of RBE2 and RBE3 the use of not coincident nodes is allowed).

4.2.7 NON STRUCTURAL AND LUMPED MASSES

a. Non structural masses shall be spread over the structure via NSM field of property cards or lumped via CONM2 cards with no offset. Variation of material mass density to simulate distributed non-structural masses shall be avoided.

b. Lumped masses shall be connected to the supporting structure via RBE3 cards as far as

possible (in order to avoid rigid regions preventing thermal elongation). If another method is adopted, the supplier shall explain and justify it.

4.2.8 SUPER-ELEMENT TECHNIQUE

a. Super-element technique is authorised. b. Grids of each mathematical model must be split into two sub-set: Exterior GRID set (or I/F Grids set); Interior GRID set. c. Interior Grids shall be specified using SESET bulk data card only. d. Disconnection of selected DOFs from the I/F GRID set shall be specified using RELEASE

bulk data card only.

4.3 INTERFACE REQUIREMENTS a. Model I/F between various items shall be compliant with respect to the requirements

reported herein. Any modification to the following guidelines requires the prior approval of the system model integrator. In any case I/F data shall be clearly documented.

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b. I/F nodes shall be independent and with six DOFs each. In order to simplify the work of the supplier, in Annex 1 of the present document the interface points between FEM Models have been defined.

c. Their ID numbers shall be the lower ones within the relevant item range (Table 4.2.3.1-1). d. If springs (CELAS2) are introduced to force recovery purposes only (i.e. if such springs

don't simulate actual structural parts with well-defined stiffness) they shall not affect the original structural behaviour.

4.4 REDUCED MODEL REQUIREMENTS

a. The used reduction procedure shall be described. b. The reduced FEM model shall adequately define the dynamic behaviour of the original FEM

model in the frequency range 0-120 Hz.

4.4.1 REDUCTION TECHNIQUES

a. The following techniques are allowed: Guyan condensation; Craig-Bampton reduction.

4.4.2 MINIMUM NODE SET

a. For Guyan reduction the following GRIDs shall be included in the reduced model and shall be clearly documented (via engineering drawings and/or FEM model plots):

1. All I/F GRIDs (to other FEMs); 2. All application GRIDs for internal and external forcing functions; 3. All lumped mass GRIDs ; 4. All GRIDs connecting internal elastic elements (CELAS2) to force recovery purposes; 5. The primary and secondary structure main load path; 6. All locations needed to demonstrate structural strength, stiffness and life integrity,

functionality and clearance; 7. All locations needed for the computation of the relative linear displacements (in micro-

vibration analysis); 8. All Grids needed to sketch the geometrical external profile.

b. For the CB models the grids to be kept physical shall be agreed on a case by case basis

with Prime. c. GRID data related to the DOFs of condensed matrices shall be provided.

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5. FEM MODEL QUALITY ASSURANCE

5.1 INTRODUCTION

a. FEM model accuracy/validity (essential for any subsequent use of the model) shall be demonstrated showing an exhaustive check procedure performed on the delivered model as herein outlined.

5.2 PRE-RUN CHECKS

a. The following Pre-Run checks shall be performed. 1. Free nodes: no unconnected nodes. 2. Node coincidence: no coincident GRID, except required (CELAS2, etc.). 3. Free edges: expected model boundaries (no disconnection between model parts). 4. Element coincidence: no coincident element (exceptions shall be documented). 5. Element shrink: no missing elements. 6. Element distortion: CTRIA3 interior angles > 10. CQUAD4 interior angles < 180. CQUAD4 skew angles > 30. CQUAD4 taper ratio < 0.5. CQUAD4 aspect ratio < 10. CQUAD4 warping < 5. CHEXA aspect ratio < 100. CHEXA warping < 45.

7. Shade image: expected element positive normal sides. 8. Element triads: expected element orientation. 9. Spring elements: between coincident nodes only. 10. Rigid elements: mathematical relations between DOFs correctly written. 11. Material properties: design properties correctly simulated. 12. Material orientation: elements correctly prepared for composite laminates properties. 13. Lumped masses: correctly located and no offset. 14. Restraints: adequately set, using suitable reference co-ordinate systems. 15. Load application points: adequately set, using suitable reference co-ordinate systems. 16. Pressure loads: adequately set along the expected positive normal direction.

b. The performed checks shall be specified. If some checks are not performed justification shall

be done.

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5.3 POST-RUN CHECKS

5.3.1 NASTRAN OUTPUT FILES

a. The NASTRAN output file shall not show WARNING messages (the run is entirely carried out but the results may be unreliable).

b. No so-called mechanisms (DOFs moving as rigid independent body inside the structure)

shall be present (caused for ex. by unconstrained directions, connections of flexible elements to very stiff ones, missing elements, etc.). In other words, MAXRATIO shall not exceed the default value (the higher this value, the closer the matrix is to singularity): MAXRATIO is maximum ratio of matrix diagonal to factor diagonal:

ii

ii

D

KMAXRATIO

where Kii = i-th diagonal term of the original stiffness matrix Dii = i-th diagonal term of the factor diagonal matrix.

c. EPSILON error ratio (work made by residual loads vs. work made by external applied loads,

indicating the accuracy of the linear equation system solution) shall be less than 1.0E-8. d. The NASTRAN Grid Point Weight Generator shall exhibit the expected mass value, CoM

location and Moments of Inertia. e. The "LOAD VECTOR" (requested via OLOAD=ALL in the Case Control Section) shall be

equal to the applied loads. f. The equilibrium between the applied external loads reported by "OLOAD RESULTANT" and

the SPC reaction forces reported by "SPCFORCE RESULTANT" shall be verified. g. The reaction forces reported by "FORCES OF SINGLE-POINT CONSTRAINT" shall be the

expected ones. h. "MAXIMUM DISPLACEMENTS" shall be the expected ones. i. The above conditions (a to h) shall be satisfied for all the check runs (Gravity Load, Strain

Energy, Rigid-Body Frequency, Thermo-Elastic and CB Reduced Model Checks).

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5.3.2 GRAVITY LOAD CHECK

a. A 1g gravitation load applied to FEM (constrained at its interface) separately in each of the X, Y, and Z CS0 axes directions shall demonstrate no excessive displacements and rotations, that is no grid points loosely connected or having very small stiffness.

b. The "SPCFORCE RESULTANT" shall be equal to the model weight (mass multiplied by the

gravitation load of 1 g = 9.80665 m/s²). c. No restraint forces shall be revealed at nodes other than the legitimate boundary condition

locations. d. Forces at Grids constrained by PARAM AUTOSPC shall not exceed 1.0E-5 times the model

weight, while moments shall not exceed 1.0E-5 times the model weight multiplied by the unit length.

5.3.3 STRAIN ENERGY CHECK

a. Strain energy check is performed by a static analysis of the unconstrained FEM. Three unitary enforced displacements (along the CS0 axes directions) and three unitary rotations are applied. Any unconstrained structure, when translated or rotated as a rigid body, has no internal loads and, therefore, strain energy; for the FEM models the value of the strain energy is not null, but it shall be closed to zero. In other words the main diagonal terms of the strain energy matrices associated to KGG (all structural DOFs), KNN (DOFs not constrained by MPCs), and KFF (all unconstrained DOFs) shall not exceed 1.0E-3. The calculated forces and moments of the internal loads shall not exceed 0.1 N and 1.5 N*m .

b. If the above results can't be achieved, the DOFs causing strain energy rising shall be clearly

identified and a justification shall be given.

5.3.4 RIGID-BODY FREQUENCY CHECK

a. A free-free normal modes analysis shall obtain the first six "rigid body" frequencies close to zero: their value shall not exceed 0.005 Hz.

b. The ratio between the highest computed frequency of the rigid body modes and the lowest

elastic mode frequency shall be less that 1.0E-3

5.3.5 NORMAL MODE ANALYSIS

a. The FEM model shall be checked by Normal Mode Analysis. The frequencies and the mode shapes shall be the expected ones.

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5.3.6 THERMO-ELASTIC CHECK

a. The model shall be checked by means of an unconstrained isothermal expansion. A uniform temperature load (via TEMPD card) shall be applied to the FEM, constrained by a statically determinate set of boundary conditions. If all the materials are replaced by a fictitious homogeneous isotropic one and the FEM is "clean" (no artificial stiffness introduced by rigid elements or bar offsets), the structure shall be stress free. The following data shall be used:

Young's modulus E = 1.0E+11 N/m² Poisson ratio = 0.3 Thermal expansion coefficient = 1.0E-5 m/mC Uniform temperature increase T = 100 C

b. The following results shall be obtained:

Maximum Von Mises stress < 0.01 MPa Maximum induced rotation < 1.0E-7 rad

c. If the above results can't be achieved, the local area causing the problem shall be clearly

identified and a justification shall be given.

5.3.7 CB REDUCED MODEL CHECKS

a. The CB reduced models shall be checked by running a Normal Modes Analysis (on the physical and reduced FEM) and comparing the mode shapes, the effective and generalised masses and the frequencies. The mass, CoM location and Moment of Inertia shall be equal between the two models.

b. Gravity load, strain-energy and rigid-body frequency checks shall be performed on the

reduced models and compared with the results of the same checks performed on the physical model.

c. Checks shall be made on Output Transformation Matrix (OTM). In particular the following are

required: 1. The combined [ATM] and [DTM] matrices shall be checked dynamically by applying

the same dynamic load on the physical and reduced models. A half-sine pulse shall be applied at the model.

2. The [DTM] matrix shall be checked statically by applying the same force to the full and reduced models. A load of (100,100,100) shall be applied at a defined point and the resulting displacements and loads shall be compared.

d. The maximum deviation of the reduced model results with respect to the full FEM model

ones shall not exceed the value reported in the following table.

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Table 5.3.7-1 - Reduced/full FEM model maximum deviations

FEM full/reduced model results

Maximum deviation

Frequencies with effective mass 10% Frequencies with effective mass 10% Effective mass for frequencies 100 Hz Effective mass for frequencies 100 Hz

3% 5% 3%

10%

e. A table showing the actual deviation of frequencies and effective masses between the two

models shall be provided. f. The modes of reduced models shall have a total effective mass equal at least to 90 % of the

rigid body mass of the original model.

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6. MODEL VALIDATION (PHASE C/D ONLY)

The requirements defined herein shall be applied to test/FEM model correlation (when requested).

6.1 STATIC MODEL

a. The correlation between the predicted (by FEM model) and measured (by static test physical model) strain values will be only pursued for the physical points which can directly be related to modelled positions on the FEM model.

b. The correlation will be considered successfully achieved when the difference between the

two models doesn't exceed 10% of stresses and displacements. If the mathematical model predictions are within the correlation criteria but underpredict the test data, the stress analysis shall be updated to reflect structural margins based on stresses that are adjusted according to the test results.

c. If necessary, updates to the FEM shall be made to achieve correlation of the model with the

test data. The correlated FEM has to maintain physical coherence (for example the physical properties of materials shall have the real value).

6.2 DYNAMIC MODEL

a. Model validation shall be accomplished by comparison of the measured (by dynamic test physical model, either STM and PFM) and predicted (by updated FEM model) mode shapes, effective masses, generalised masses and frequencies.

b. The correlation between the predicted and measured values will be considered successfully

achieved when: a. the differences between the measured and predicted frequencies are less than 10%

(5% for target modes); b. the differences between the measured (if applicable) and predicted effective masses

are less than 10% (5% for target modes); c. the cross-orthogonality check presents values higher than 0.9 for diagonal elements

and less than 0.1 for off-diagonal elements. c. If MAC will be used as an additional indicator of the correlation between measured and

predicted mode-shapes, the MAC diagonal elements shall be higher than 0.9. d. If necessary, updates to the FEM shall be made to achieve correlation of the model with the

test data. The correlated FEM has to maintain physical coherence (for example the physical

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properties of materials shall have the real value).

7. DELIVERABLES

7.1 DELIVERABLE FEM ITEM LIST

a. FEM Model files (para. 7.2) b. Mathematical Model Delivery Document (MMDD). (para. 7.3) c. Mathematical Model Description (MMD). (para. 8)

7.2 FEM MODEL FILES REQUIREMENTS

a. All models have to be provided both in stowed and deployed configuration, when different. b. Effort shall be made in order to obtain, to the maximum extent, a unique model for several

analyses (modal, stress, thermo-elastic, etc.). c. The FEM model files to be delivered are, at least, the following ones:

1. NASTRAN input files; 2. NASTRAN bulk data; 3. NASTRAN matrices (including ATM, DTM, LTM1, LTM2, for CB reduced models); 4. Analysis results.

d. All data files shall be supplied in ASCII format; analysis results shall be supplied in ASCII

and binary format. e. The model name, issue and date shall be clearly specified.

7.2.1 NASTRAN INPUT FILES

a. NASTRAN input files (containing NASTRAN Statement, File Management Section, Executive Control Section and Case Control Section) shall be supplied for all analysis types.

b. NASTRAN input files shall be supplied separated from bulk data files.

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7.2.2 NASTRAN BULK DATA

a. The full bulk data deck shall be such that it can run without any user defined DMAP. b. The bulk data deck shall be divided in different sections for the different Spacecraft

structures and items: Carrier Module Descent Module Parachute RDA Rover Vehicle PamCam Optical Bench WISDOM units ALD Structure SPDS units MIRU MOMA units RAMAN units DRILL and SPDS EU, DRILL+MAMISS MSB

c. For the most complex items a further sub-division into sub-structures may be performed. In

this case the files organisation shall be briefly explained (a file INDEX.TXT is suggested). d. NASTRAN bulk data files shall be delivered for all analysis types, if different.

7.2.2.1 NASTRAN BULK DATA FILE ORGANISATION

a. All the names of the FEM files shall be unique; for different issues the same file shall not have the same name.

b. The name of files shall clearly identify the FEM section (7.2.2 b), the sub-structure, the issue

and the analysis type. The following scheme is required:

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SEC-STR-ISS-Anl . extension

Where: SEC is the section: CM = Carrier Module DM = Descent Module PAR = Parachute RDA = Radar Doppler Assembly

RV = Rover Vehicle ALD = Analytical Laboratory Drawer DRILL =Drill SPDS= Spds EQP/INST = Equipment/Instruments

STR is the sub-structure (for ex. the Solar Wings of the ROVER). If the file refers to

the whole section, STR shall not be specified. ISS is the issue; it may be a number or an abbreviation (for ex. 001 or mod1). If a

file remains the same in two successive deliveries, ISS shall be the same. Anl is the analysis type. If a unique model is used for all the analyses, Anl shall not

be specified.

c. For each section, bulk data shall be divided into several files, containing the specific NASTRAN cards. The following scheme estensions is required (* stands for the FEM name):

*.GEO GEOmetry: co-ordinate systems, nodes, elements, loads and constrains; *.IF InterFace: nodes or elements connecting the different sections of the FEM; *.PRO PROperties and materials for all analyses; *.TEM TEMperatures;

7.2.2.2 NASTRAN BULK DATA COMMENTS

a. The bulk data file will function as an additional working level documentation. It works as a road map in describing the model. Exhaustive comments into English language shall be included.

b. In particular, lumped masses, NSM and element section properties shall be well detailed.

7.2.3 NASTRAN MATRICES

a. Deliverable matrices shall be supplied in NASTRAN OUTPUT2, OUTPUT4 or DMIG ASCII

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format (binary format not allowed).

7.2.4 ANALYSIS RESULTS

a. The following files shall be supplied:

NASTRAN .f06 files NASTRAN .op2 files

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7.3 DATA AND INFORMATION EXCHANGE

a. The delivery of FEMs and related documents shall be done through FTP, in accordance with the applicable EXOMARS procedure.

b. Every FEM delivery shall be accompanied by the Mathematical Model Delivery Document

(MMDD). c. The MMDD shall indicate, at least:

1. the name of the delivered files containing the FEM; 2. the name of the modified files, from which the delivered FEM derives; 3. all the changes between the delivered FEM and the previous one; 4. the mass properties of the FEM; 5. the frequencies and the effective masses (in percentage of the total mass); 6. the reference to the Mathematical Model Description and to the documents, if any,

containing the analysis performed on the delivered FEM. d. Every FEM shall be described in a Mathematical Model Description (MMD).

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8. MATHEMATICAL MODEL DESCRIPTION (MMD)

8.1 CONTENTS

Table of contents 8.1-1 lists the minimum subjects to be dealt with in the model description report.

Table 8.1-1 - Model description report: Table of Content

. LIST OF ACRONYMS

. . LIST OF SYMBOLS

1 SCOPE

2 DOCUMENTS

2.1 APPLICABLE DOCUMENTS

2.2 REFERENCE DOCUMENTS

3 DESCRIPTION

3.1 OVERALL DESCRIPTION

3.2 UNIT SYSTEM

3.3 CO-ORDINATE SYSTEMS

3.4 MASS AND COM BUDGET

3.5 MATERIAL CHARACTERISTICS

4 FEM MODEL

4.1 FEM CODE AND PRE/POST-PROCESSORS

4.2 FEM UNITS

4.3 FEM CO-ORDINATE SYSTEMS

4.4 FEM MODEL DESCRIPTION 4.4.1 Assumption and idealisations 4.4.2 Geometry 4.4.3 Interfaces 4.4.4 Boundary conditions 4.4.5 Properties and materials 4.4.6 Mass distribution summary 4.4.7 Non linearity 4.4.8 Other special modelling features

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4.5 FEM/ MODEL CHECKS 4.5.1 Pre-run Checks 4.5.2 Gravity load check 4.5.3 Strain energy check 4.5.4 Rigid-body frequency check 4.5.5 Thermo-elastic check 4.5.6 Normal Modes Analysis

5 REDUCED/CONDENSED MODEL

5.1 MODEL DESCRIPTION 5.1.1 Reduction procedure 5.1.2 I/F and boundary DOF maps 5.1.3 Wire-frame model description 5.1.4 Output transformation matrices (OTM)

5.2 REDUCED MODEL CHECKS 5.2.1 Normal Modes Analysis results

5.2.1.1

Frequency comparison with respect to FEM

5.2.1.2

Effective mass comparison with respect to FEM

5.2.2 Strain energy check 5.2.3 OTM checks

6 NON-COMPLIANCIES WITH FEM REQUIREMENTS

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8.2 REQUIREMENTS

In the model description shall be included: a. the geometric relationships between any local auxiliary co-ordinate system and own FEM co-

ordinate systems and between the latter and the NASTRAN basic co-ordinate system, CS0 (in para 4.3);

b. suitable sketches and FEM model plots of the co-ordinate systems (in para 4.3); c. detailed plots of the model clearly showing all nodes, elements, connectivity and relevant

numbering and types (in para 4.4); d. all calculations and rationales used to generate the model-input data. In general, all input

data used for the model shall be clearly documented (in para 4.4); e. the physical meaning of the rigid elements and a description of the purpose, location, and I/F

connectivity (in para 4.4.2); f. mass properties of the models (i.e. masses, moment of inertia, CoM location, and rigid body

mass matrix). Adequate documentation shall be provided for units and co-ordinate system used for mass property generation (in para 4.4.6);

g. pre-run checks successful completion. Exceptions shall be documented (in para 4.5.1); h. post-run checks obtained through all the check procedure, with suitable model plots, if

needed (from para 4.5.2 to para 4.5.6); i. frequencies and effective masses, in percentage of the total mass (in para 4.5.5).

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ANNEX 1

INTERFACE NODES DEFINITION

1. ROVER VEHICLE to ALD I/F Nodes (RV side):

500001 (X, Y, Z in RM co-ordinate system - see ICD document) 500002 (X, Y, Z in RM co-ordinate system - see ICD document) 500003 (X, Y, Z in RM co-ordinate system - see ICD document)

2. ROVER VEHICLE to PANCAM OPTICAL BENCH I/F Nodes (RV side): First node 500101 (X, Y, Z in RM co-ordinate system - see ICD document) Remaining I/F nodes in accordance with the latest ICD following a progressive numbering starting from the first one.

3. ROVER VEHICLE to WISDOM ANTENNA I/F Nodes (RV side): First node 500201 (X, Y, Z in RM co-ordinate system - see ICD document) Remaining I/F nodes in accordance with the latest ICD following a progressive numbering starting from the first one.

4. ROVER VEHICLE to WISDOM EU I/F Nodes (RV side): First node 500301 (X, Y, Z in RM co-ordinate system - see ICD document) Remaining I/F nodes in accordance with the latest ICD following a progressive numbering starting from the first one.

5. PANCAM OPTICAL BENCH to RV I/F Nodes (PAN CAM side): First node 700001 (coordinates as per ICD document) Remaining I/F nodes in accordance with the latest ICD following a progressive numbering starting from the first one.

6. WISDOM ANTENNA to RV I/F Nodes (WISDOM ANTENNA side): First node 800001 (coordinates as per ICD document) Remaining I/F nodes in accordance with the latest ICD following a progressive numbering starting from the first one.

7. WISDOM EU to RV I/F Nodes (WISDOM EU side): First node 850001 (coordinates as per ICD document) Remaining I/F nodes in accordance with the latest ICD following a progressive numbering starting from the first one.

8. ALD to ROVER VEHICLE I/F Nodes (ALD side): 100001 (as per ICD document) 100002 (as per ICD document) 100003 (as per ICD document)

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9. ALD to SPDS - CSHS I/F Nodes (ALD side):

First node 100101 (as per ICD document) Remaining I/F nodes in accordance with the latest ICD following a progressive numbering starting from the first one.

10. ALD to SPDS – CRUSHING STATION I/F Nodes (ALD side): First node 100201 (as per ICD document) Remaining I/F nodes in accordance with the latest ICD following a progressive numbering starting from the first one.

11. ALD to SPDS - PSDDS I/F Nodes (ALD side): First node 100301 (as per ICD document) Remaining I/F nodes in accordance with the latest ICD following a progressive numbering starting from the first one.

12. ALD to SPDS - CAROUSEL I/F Nodes (ALD side): First node 100401 (as per ICD document) Remaining I/F nodes in accordance with the latest ICD following a progressive numbering starting from the first one.

13. SPDS - CSHS to ALD I/F Nodes (SPDS - CSHS side): First node 200001 (as per ICD document) Remaining I/F nodes in accordance with the latest ICD following a progressive numbering starting from the first one.

14. SPDS – CRUSHING STATION to ALD I/F Nodes (SPDS – CRUSHING STATION side): First node 210001 (as per ICD document) Remaining I/F nodes in accordance with the latest ICD following a progressive numbering starting from the first one.

15. SPDS - PSDDS to ALD I/F Nodes (SPDS - PSDDS side): First node 220001 (as per ICD document) Remaining I/F nodes in accordance with the latest ICD following a progressive numbering starting from the first one.

16. SPDS - CAROUSEL to ALD I/F Nodes (SPDS CAROUSEL side): First node 230001 (as per ICD document) Remaining I/F nodes in accordance with the latest ICD following a progressive numbering starting from the first one.

17. ALD to MIRU I/F Nodes (ALD side): First node 100601 (as per ICD document) Remaining I/F nodes in accordance with the latest ICD following a progressive numbering starting from the first one.

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18. MIRU to ALD I/F Nodes (MIRU side):


19. ALD to MOMA LDMS I/F Nodes (ALD side): First node 100701 (as per ICD document) Remaining I/F nodes in accordance with the latest ICD following a progressive numbering starting from the first one.

20. ALD to MOMA GC I/F Nodes (ALD side): First node 100801 (as per ICD document) Remaining I/F nodes in accordance with the latest ICD following a progressive numbering starting from the first one.

21. ALD to MOMA LASER EU I/F Nodes (ALD side): First node 100901 (as per ICD document) Remaining I/F nodes in accordance with the latest ICD following a progressive numbering starting from the first one.

22. ALD to MOMA EU I/F Nodes (ALD side): First node 101001 (as per ICD document) Remaining I/F nodes in accordance with the latest ICD following a progressive numbering starting from the first one.

23. MOMA LDMS to ALD I/F Nodes (MOMA LDMS side): First node 260001 (as per ICD document) Remaining I/F nodes in accordance with the latest ICD following a progressive numbering starting from the first one.

24. MOMA GC to ALD I/F Nodes (MOMA GC side): First node 270001 (as per ICD document) Remaining I/F nodes in accordance with the latest ICD following a progressive numbering starting from the first one.

25. MOMA LASER EU to ALD I/F Nodes (MOMA LASER EU side):


26. MOMA EU to ALD I/F Nodes (MOMA EU side): First node 290001 (as per ICD document) Remaining I/F nodes in accordance with the latest ICD following a progressive numbering starting from the first one.

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27. ALD to RAMAN SPU I/F Nodes (ALD side): First node 101101 (as per ICD document) Remaining I/F nodes in accordance with the latest ICD following a progressive numbering starting from the first one.

28. ALD to RAMAN OPTICAL HEAD I/F Nodes (ALD side): First node 101201 (as per ICD document) Remaining I/F nodes in accordance with the latest ICD following a progressive numbering starting from the first one.

29. ALD to RAMAN ICEU I/F Nodes (ALD side): First node 101301 (as per ICD document) Remaining I/F nodes in accordance with the latest ICD following a progressive numbering starting from the first one.

30. RAMAN SPU to ALD I/F Nodes (RAMAN SPU side): First node 300001 (as per ICD document) Remaining I/F nodes in accordance with the latest ICD following a progressive numbering starting from the first one.

31. RAMAN OPTICAL HEAD to ALD I/F Nodes (RAMAN OPTICAL HEAD side): First node 310001 (as per ICD document) Remaining I/F nodes in accordance with the latest ICD following a progressive numbering starting from the first one.

32. RAMAN ICEU to ALD I/F Nodes (RAMAN ICEU side): First node 320001 (as per ICD document) Remaining I/F nodes in accordance with the latest ICD following a progressive numbering starting from the first one.

33. ALD to DRILL SPDS EU I/F Nodes (ALD side): First node 101401 (as per ICD document) Remaining I/F nodes in accordance with the latest ICD following a progressive numbering starting from the first one.

34. DRILL SPDS EU to ALD I/F Nodes (DRIL SPDS EU side): First node 330001 (as per ICD document) Remaining I/F nodes in accordance with the latest ICD following a progressive numbering starting from the first one.

35. ROVER VEHICLE to DRILL I/F Nodes (ROVER VEHICLE side): First node 500401 (X, Y, Z in RM co-ordinate system - see ICD document) Remaining I/F nodes in accordance with the latest ICD following a progressive numbering starting from the first one.

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36. DRILL to ROVER VEHICLE I/F Nodes (DRILL side): First node 400001 (as per ICD document) Remaining I/F nodes in accordance with the latest ICD following a progressive numbering starting from the first one.

37. CARRIER MODULE to LAUNCHER I/F Nodes : First node 1000001 (as per ICD document) Remaining I/F nodes in accordance with the latest ICD following a progressive numbering starting from the first one.

38. CARRIER MODULE to DESCENT MODULE I/F Nodes (CM side): First node 1010001 (as per ICD document) Remaining I/F nodes in accordance with the latest ICD following a progressive numbering starting from the first one.

39. DESCENT MODULE to CARRIER MODULE I/F Nodes (DM side) : First node 1100001 (as per ICD document) Remaining I/F nodes in accordance with the latest ICD following a progressive numbering starting from the first one.

40. DESCENT MODULE to PARACHUTE I/F Nodes (DM side): First node 1110001 (as per ICD document) Remaining I/F nodes in accordance with the latest ICD following a progressive numbering starting from the first one.

41. PARACHUTE to DESCENT MODULE I/F Nodes (PARACHUTE side):


42. DESCENT MODULE to RDA I/F Nodes (DM side):


43. RDA to DESCENT MODULE I/F Nodes (RDA side):


44. DESCENT MODULE to ROVER VEHICLE (DM side):


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45. ROVER VEHICLE to DESCENT MODULE I/F Nodes (RV side):

Node IDs are as follows: RV BODY : 549010, 549030, 549050 LSS (wheels) : 699910, 699920, 699930, 699940, 699950, 699960 LSS (snubbers) : 699810, 699820, 699830, 699840, 699850, 699860

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