Strategic Technologies for Space Programmes Mechanical Engineering

Transcription

1 Strategic Technologies for Space Programmes Mechanical Engineering Issues and trends. By M.Klein European Space Agency Estec Noordwijk (NL) michel.klein 02/02/05, Page 1

2 Strategic Technologies for Space Programmes Mechanical Engineering System Engineering & Technical Mission Huygens-Cassini Project Huygens Probe Product Probe structure Elements / Equipment Re-entry shield Materials Thermal protection Engineering Support IT Aspects Hardware Engineering application access Concluding Remarks 02/02/05, Page 2

3 Cassini-Huygens 02/02/05, Page 3

4 Mission Drivers (Huygens-Cassini) Design, Verification, Launch Arrival at Target Life cycle extended in time Time (7 years for Huygens, 10 years for Rosetta) Operations team is different from project team Responses Stronger PDM / knowledge needed Re-use of data / models (e.g. thermal, structural) Maintenance of eng. tools and models becomes a specific task (for years ) 02/02/05, Page 4

5 Project Drivers Need to reduce time to market / cost (Huygens Probe) Design, Verification, Launch Arrival at Target Time Multiple partners in all projects (large data flow between different eng. tools) Consequences Re-use of elements, building blocks, equipment Virtual spacecraft approach Interfaces & standards 02/02/05, Page 5

6 Consequences cntd. Virtual Spacecraft approach philosophy Perform asap simulations of the system / spacecraft Evolve simulations from early phases 0 / A to C / D / F up to E Feasibility Design AIT Launch Operations Mechanical Electrical / RF Data Handling Simple state model EM hdw. FM hdw. Time AOCS, etc System model equipt. Softw. Simulator hdw. In loop use validated equipt. simulator validation & s/c simul. for Ops Model driven approach at system level and lower levels Simulation is the key word 02/02/05, Page 6

7 Consequences cntd. Virtual Spacecraft approach philosophy Feasibility Design AIT Launch Operations Mechanical Electrical / RF Data Handling Simple state model EM hdw. FM hdw. Time AOCS, etc System model equipt. Softw. Simulator hdw. In loop use validated equipt. simulator validation & s/c simul. for Ops Virtual design models Virtual AIT Virtual Operations Reducing risks as far as possible before testing, but not eliminating testing (loads, stresses, static, acoustic, temperature, margins ) (prepare AIT, prepare procedures ) (prepare operations ) (virtual models need to be validated at all levels) 02/02/05, Page 7

8 Consequences cntd. Interfaces & standards To exchange data between multiple partners using different platforms / tools To enable exchange of virtual models for assembly at system level ECSS-E-10 Part 7 Data Exchange Standard But also To share a common view on system engineering approach ECSS-E-10 Part 1 System Engineering 02/02/05, Page 8

9 Product Drivers (Probe Structure) Complexity (wrt technical e.g interaction of disciplines, active control-, wrt programmatics) target performances Limit over-design Increase robustness => optimisation with robustness Decrease cost e.g. decrease design iterations Responses Common data set shared by all technical disciplines / Parties => PDM tools Derivation of technical discipline models from this common data set E.g. structural, thermal, EMC, RF Common data This is not achieved consistently yet for Aerospace Tool Structures Thermal EMC 02/02/05, Page 9

10 Product Responses contd. Non-linear analysis is more often used Buckling Pre-load, interface aspects Large displacements of very flexible items (antennas) Composite elements modelling / lay up / stress Needs improvement / integration» specifically wrt precise fibre placement machines» 3D stresses evaluation Interaction with Control system Damping, shape control of structures Take into account inevitable scatter => design to robustness stochastic approach (or fuzzy) now affordable (e.g. Higher order Derivatives) However, Physics should not be forgotten 02/02/05, Page 10

11 Product Responses contd. Multi-disciplinary Faster iteration means between the different disciplines => interfaces / standards Juxtaposed tools CAUTION: applies only to weak coupling!! Multi-physics Mandatory when strong coupling of physics Needs to consider off diagonal coupling terms Integrated tools E.g. acoustics structures, aero-thermo dynamics E.g. structure & mechanisms elements integration 02/02/05, Page 11

12 Elements / Equipment (Re-entry Shield) Drivers Needs are similar than those for Products Special needs for specific elements, but rather at material level (e.g. with ablators) But in addition novel types of elements exist Multi-functional elements / smart elements / health management systems» require implementation of the control loop» modelling needs should be reducible to those of Products MEMS, MEOS which will need» modelling / design tools (reliability issues) (specific software are emerging)» models when used in combination with other elements (e.g. cooler on a ship)» probably active control modelling Novel type of materials might generate new needs for Material modelling E.g. multifunctional carbon nano-tube material (longer term) 02/02/05, Page 12

13 Elements / Equipment contd. Responses Needs are covered for traditional products For ablators, validation of models / experimental identification is still an issue For novel elements, no tools in our domain 02/02/05, Page 13

14 Materials Drivers (Ablator) At material science level, trend to design the material and predict macroscopic properties Favoured by computational capabilities Very active at nano materials level Nano materials can combine mechanisms and electronic functions» a fully new type of materials pointing its nose» at research level, not for engineering application yet» but to be followed carefully At macroscopic level, needs wrt material modelling are (see Products) Lay-up help (specifically wrt precise fibre placement machines) 3D stresses evaluation 02/02/05, Page 14

15 Engineering Support IT Aspects Hardware Drivers Computational power Multi-processor machines Linux Clusters Dramatic computational power increase at low cost Virtual reality visualisation Technical capabilities exist, are expensive but are only rarely used in the Space Industry 02/02/05, Page 15

16 Engineering Support IT Aspects Hardware Consequences Computational Power Stochastic approach rendered affordable (on company internal computers) Non-linearity rendered affordable Virtual reality Not all technological capabilities used, e.g. for virtual AIT 02/02/05, Page 16

17 Engineering Support IT Aspects Engineering application access Drivers GRID Not really used at engineering level yet in Space area Reason: GRID adapted to no-fee applications engineering applications not adapted yet / security problem Consequences GRID Use could make stochastic approach even more affordable for complex demanding cases, e.g. structural buckling via use of company external resources on an as needed basis EC activity DISTAL attempted to define an operational mode product exist, is operational, is security correct However, problems with Vendors (licensing for multiple parallel runs) 02/02/05, Page 17

18 Concluding Remarks To respond to strategic needs of Aerospace mechanical engineering for the future at system & lower level, following capabilities are required» to receive / deliver model for system level analysis / simulations» to perform non-linear analyses» to perform robustness analyses» to include Control aspects» to ensure multidiscipline analyses» to perform virtual AIT and use Virtual Reality» and to provide validation evidence for available options In addition, following aspects would be an asset» derivation of discipline models from a common dataset» Provision of an integrated analysis capability» Management of the models related data flow and ensuring their configuration control» for specific advanced applications, performance of true multiphysics analyses 02/02/05, Page 18