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Design, Manufacture, Transport and Integration on-site in Chile of ALMA Antennas ANALYSES ACTIVITY

Design, Manufacture, Transport and Integration on-site in Chile of ALMA Antennas ANALYSES ACTIVITY PM#01- 01 February 2006. List of Analysis Activity. a) Finite Element Analysis (DRD-23) - Gravity analysis, - Wind loading analysis - Thermal modelling and thermal analyses

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Design, Manufacture, Transport and Integration on-site in Chile of ALMA Antennas ANALYSES ACTIVITY

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  1. Design, Manufacture, Transport and Integration on-site in Chile of ALMA Antennas • ANALYSES ACTIVITY • PM#01- 01 February 2006

  2. List of Analysis Activity a) Finite Element Analysis (DRD-23) - Gravity analysis, - Wind loading analysis - Thermal modelling and thermal analyses - Stress analysis and fatigue verification and survival conditions load cases - Dynamic analyses (eigenfrequency) - Seismic analysis b) Error Budget Computations (DRD-21): - Antenna surface error budget - Pointing error budget - Path length error computation c) Mass and Balance Budget (DRD-24) d) Dynamic servo simulation analysis for fast switching and other dynamical performances of the antenna. (DRD-23)

  3. Analysis Activity Preparation - Verification Plan - Engineering Activity - Industrialization 2D study 3D study 3D MODEL ProEngineer

  4. Analysis Activity Preparation FEM MODEL ANSYS 3D MODEL ProEngineer

  5. Analysis Activity Preparation FEM MODEL ANSYS FEM MODEL NASTRAN • - Gravity Analysis • - Wind distortion analysis • Thermal distortion analysis • Dynamic analysis • Stress analysis • Seismic analysis • Mass and balance Local FEM model

  6. Gravity Analysis • Error Budget Analysis • Surface accuracy • Pointing Error • Path lenght error The Gravity analysis will be an input for • Antenna performance • Subreflector look-up table • Pointing telescope look-up table • Instruments behaviour • Etc. Mass and balance budget

  7. Wind and Thermal Analysis FEM MODEL Ansys/Nastran 3D MODEL ProEngineer Generation of: CFD Model Thermal Model

  8. Wind Analysis exchange data • Input data: • Antenna CAD model tailored for Wind Analysis • Environmental boundary conditions including antenna orientation • Output data: • Pressure (or Forces) acting on the relevant Antenna surface • Heat transfer coefficient An agreement on the exchange data format is under definition

  9. Wind Analysis Logic CFD Analysis Solver & Post-Processing FLUENT Geometrical Preprocessing GAMBIT EIE CAD Model • Analysis Results • Pressure Loads • Heat Transfer coefficien

  10. Wind Analysis Logic WIND ANALYSIS Analysis Report (PPDR) EIE CAD Model CFD INPUTS to ANTENNA System Analysis

  11. Backup chart Wind Analysis – Antenna orientation x Analysis cases required by spec for error budget 0 Additional analysis cases for Metrology calculation and simulation Additional analysis cases to cover Load Survival condition (as per para 9.1.3 of ALMA spec)

  12. Thermal Analysis: Summary • Alcatel Alenia Space Italia is responsible for the execution of the thermal analysis for the whole antenna. Within this responsibility AASI will: • Generate the Geometrical Mathematical Model (GMM) and the Thermal Mathematical Model (TMM) • Run the thermal analyses for the design loads cases in order to generate the temperature maps for the thermal distortion analysis and contribute to the verification of antenna overall design • Define/verify subsystems and equipments operational and not operational thermal environment

  13. THERMAL MODELLING ACTIVITY GMM • The GMM of the Antenna will be prepared by using THERMICA S/W in the following steps: • Identification of the relevant geometrical data contained in the 3D CAD model • Generation of the Geometrical Model of the Antenna that will contain the relevant geometry, the geometrical and thermal nodes definition and thermo-optical properties. • Evaluation with THERMICA of the radiative thermal network and the solar fluxes absorbed by the exposed surfaces

  14. THERMAL MODELLING ACTIVITY TMM • The TMM of the Antenna will be prepared by using ESATAN S/W in the following steps: • Introduction of the linear conductors network (representing the conductive and convective links between the thermal nodes), the radiative network and the thermal loads generated by THERMICA. The linear conductors are calculated taking in to account the relevant materials lay-up, the materials thermal properties and the contact conductance • Introduction of a dedicated routine to properly simulate the radiative exchange in the terrestrial environment (including contribution from water vapour radiation emission) • Accounting of the convective exchange with atmosphere through different sets of heat transfer coefficients provided by the CFD analysis for all the relevant wind conditions

  15. THERMAL MODELLING ACTIVITY • THERMAL ANALYSIS RUNS • The most significant thermo-elastic cases presented in the Proposal will be critically revised and the relevant thermal analysis cases will be performed • Thermal analysis output temperatures will be transferred the to the structural finite elements model through a specific procedure for mapping the thermal node temperatures into the structural model.

  16. Wind and Thermal Analysis results • Error Budget Analysis • Surface accuracy • Pointing Error • Path lenght error The Wind and Thermal Analysis will be used as input for : • Antenna performance • Subassembly verification • Subassembly dimensioning • Engineering Calculation • Etc. • Stress Analysis • Stress verification • Fatigue verification • Failure verification • Etc.

  17. Dynamic Analysis • Dynamic Analysis • Resonance frequency • Modal Shape • Modal participation factor • Mass participation Factor • Modal Kinetic energy. The Ansys FEM model shall be used for the dynamic analysis : • Antenna performance • Subassembly verification • Subassembly dimensioning • Engineering Calculation • Servo Analysis • structural dynamic effects • effect of wind disturbances • encoder system • Subsystem

  18. Seismic Analysis • Stress Analysis • Stress verification • Fatigue verification • Failure verification • Etc. The Ansys FEM model shall be used for the seismic analysis : • Antenna performance • Subassembly verification • Subassembly dimensioning • Engineering Calculation

  19. Error budget analysis • Thermal analysis • Output temperature • Subsystem analysis • Bearing errors • Encoders coupling • Servo errors • Aging evaluation • Etc. Gravity analysis • Wind Analysis • Pressure loads FEM analysis Matlab Postprocessor Pointing Error Absolute pointing error Offset pointing error Surface Accuracy Path lenght Error

  20. GLOBAL FEA MODEL • GLOBAL MODEL: • 113000 NODES • 67000 ELEMENTS • SHELL 99 (CFRP) • SHELL 63 (STEEL PLATES) • BEAM 4 • COMBIN 14 (SPRINGS) • MASS 21 FEA model of azimuth bearing, modelled by vertical springs and radial springs Back-Up Structure - detail GLOBAL MODEL 45° elevation

  21. GLOBAL FEA MODEL RECEIVER CABIN GLOBAL MODEL – CALL FOR TENDER 45° elevation BACK-UP STRUCTURE 16 SLICES, UPPER AND LOWER SKIN EVERYTHING MODELED WITH MULTILAYER SHELL ELEMENT

  22. GLOBAL FEA MODEL CONNECTION BETWEEN YOKE AND RECEIVER CABIN TANGENTIAL COSTRAINT GIVED BY THE ELEVATION DRIVE CONNECTION BETWEEN YOKE AND RECEIVER CABIN LATERAL COSTRAINT GIVED BY THE ELEVATION DRIVE WHEELS

  23. FEM ANALYSIS AZIMUTH BEARING TANGENTIAL SPRINGS (AZ DRIVES) GLOBAL MODEL – CALL FOR TENDER 45° elevation AZIMUTH BEARING VERTICAL AND RADIAL SPRINGS

  24. GLOBAL FEA MODEL GLOBAL MODEL – CALL FOR TENDER 45° elevation • NEW GLOBAL MODEL • 90° elevation • MAIN CHANGES: • REFLECTOR PANELS ELEMENTS MODIFIED, NOW THE SAME MODEL CAN BE USED FOR STATIC ANALYSES AND FOR MODAL ANALYSES • ELEVATION AXIS BOX MODELED WITH SHELL ELEMENTS INSTEAD OF BEAM ELEMENTS • APEX STRUCTURE MODELED WITH SHELL ELEMENTS INSTEAD OF BEAM ELEMENTS • PLATFORFMS TOTALLY REDESIGNED • INTERFACE FLANGES WITH THE FOUNDATION PAD, WE HAVE PUT IN THE GLOBAL MODEL THE DETAILED MODEL PROVIDED BY ESO

  25. GLOBAL FEA MODEL APEX STRUCTURE – CFRP INTERFACE CYLINDER – ALUMINUM SUBREFLECTOR – ALUMINUM QUADRUPODE LEGS

  26. GLOBAL FEA MODEL INTERFACE FLANGES WITH THE FOUNDATION PAD ONLY THE CONTACT SURFACE IS CONNECTED TO THE BASE STRUCTURE ELEVATION AXIS BOX

  27. GLOBAL FEA MODEL PLATFORMS ALL THE CABINETS ARE MODELED AS STRUCTURAL MASSES THIS STRUCTURE HAS TO BE IMPROVED

  28. GLOBAL FEA MODEL NEXT MODEL ACTUAL MODEL AZIMUTH BEARING REDUCED DIAMETER INTERFACE FLANGES WITH TRANSPORTER MODIFIED POSITION

  29. GLOBAL FEA MODEL NEXT MODEL ACTUAL MODEL INTERFACE FLANGE BETWEEN ARMS AND YOKE MOVED BECAUSE OF THE NEW ICD WITH THE TRANSPORTER

  30. GLOBAL FEA MODEL NEXT MODEL ACTUAL MODEL MORE DETAILED MODEL OF THE AZ BEARING AND OF THE INTERFACE WITH THE FOUNDATION PAD

  31. GLOBAL FEA MODEL NEXT MODEL NEXT MODEL MORE DETAILED MODEL OF THE AZ BEARING AND OF THE INTERFACE WITH THE FOUNDATION PAD

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