Presentation is loading. Please wait.

Presentation is loading. Please wait.

TMT.OPT.PRE.07.056.REL01 HPS-280001-0105 – Volume 1 – October 24-25 2007 – Slide 1 TMT M1 Segment Support Assembly (SSA) Preliminary Design Review (PDR)

Similar presentations


Presentation on theme: "TMT.OPT.PRE.07.056.REL01 HPS-280001-0105 – Volume 1 – October 24-25 2007 – Slide 1 TMT M1 Segment Support Assembly (SSA) Preliminary Design Review (PDR)"— Presentation transcript:

1 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 1 TMT M1 Segment Support Assembly (SSA) Preliminary Design Review (PDR) Volume-1: OVERVIEW Pasadena, California October 24-25, 2007 Contributors to the development effort: from IMTEC RJ Ponchione, Eric Ponslet, Shahriar Setoodeh, Vince Stephens, Alan Tubb, Eric Williams from the TMT Project George Angeli, Curt Baffes, Doug MacMynowski, Terry Mast, Jerry Nelson, Ben Platt, Lennon Rodgers, Mark Sirota, Gary Sanders, Larry Stepp, Kei Szeto TMT Confidential The Information herein contains Cost Estimates and Business Strategies Proprietary to the TMT Project and may be used by the recipient only for the purpose of performing a confidential internal review of the TMT Construction Proposal. Disclosure outside of the TMT Project and its External Advisory Panel is subject to the prior written approval of the TMT Project Manager. * Note: HYTEC, Inc. merged with IMTEC Inc. in March 2007.

2 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 2 Outline Volume-1: Overview –Thirty Meter Telescope Overview –SSA Project Overview –Key Design Requirements –Design Concept –SSA Preliminary Design Key Subsystems –Axial Support –Lateral Support –Tower, Guide Flexure, Locks, Registration –Warping Harness –Subcell Volume-2: System Level Calculations –M1 Segmentation –Segmentation Correction (for Variable Segment Geometry) –Budgets: Installation & Alignment Edge Gap Actuator Stroke Mass

3 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 3 Outline Volume-3: System-Level Finite Element Analysis –Model Description –Optical Performance –Stiffness and Modes –Buckling –Sensitivity Analyses –Stress Analysis –Backup Slides Volume-4: Warping Harness Design and Analysis –Fundamental Approach & Architecture –Warping Harness Requirements Opto-mechanical Mechanical –Design Concept –Performance Analysis Actuator arrangement Surface correction –Derived Requirements for Components –Mechanical & Electrical Design –Quantization Error Estimate

4 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 4 Outline Volume-5: Flexure Design and Analysis –Design Load Combinations –Central Diaphragm –Rod-Type Flexures –Lateral Guide Flexure Volume-6: Subcell Integration & Segment Handling –Subcell Integration & Alignment Fixed Frame Installation Dummy Mass Subcell Alignment –Segment Lifting Jack & Lifting Talon Jack design Lifting Talon design Volume-7: Summary and Future Plans –Prototype Testing Test Plans –Component testing –Full Prototype testing –Schedule –Summary Where we are and where we’re going Technical Risks –Conclusions

5 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 5 BRIEF TELESCOPE OVERVIEW Thirty Meter Telescope

6 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 6 M1 Array 30m Diameter ~60m ROC 492 Segments –1.44m x 45mm 1 Note 1) 45mm for Glass-Ceramic, 50mm for Fused Silica PSA On Mirror Cell

7 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 7 Segment Size Nominal Segment size is 1.44 m across vertices –Limited by blank size to maintain several competitive suppliers Thickness: –45 mm if glass ceramic –50 mm if fused silica (ULE) Aperture limits: –Outermost corners: 15.0 m radius –Innermost corners: 1.45 m radius m diameter

8 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 8 M1 Parameters Fundamental M1 Parameters: –Constant-gap segmentation: 82 different segment shapes Six identical sectors –Nominal segment: 1.44m regular hexagonal meniscus Glass-Ceramic, 45mm thick 60m paraxial radius of curvature –Neglect asphericity in support design activities –Average segment ROC ~62.5m Assume worst case CTE = ppm/°C in analyses –Alternate segment: Fused Silica, 50mm thick meniscus SSA can be re-tuned to accommodate X PSA Y PSA Z PSA Y PSA Z PSA X PSA Z PSA Y PSA X PSA SSA Base Cell Truss 1.44 m 45 mm

9 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 9 M1 Parameters Segmentation Pattern: Sector Boundary - Note Fixed Frame Clocking 60 ◦ View from Sky

10 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 10 SSA PROJECT OVERVIEW Thirty Meter Telescope

11 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 11 SSA Project Scope IMTEC Design/Development Responsibilities Include: –Segment Support Assembly (SSA) –Segment Lifting Jack –Segment Lifting Talon Attaches Mounted Segment Assembly (MSA) to Segment Handling Crane –Subcell Integration Hardware: Mass Simulator Surveying Target Holders Subcell Alignment Tooling –Release Prototype Drawings –Build, Test and Deliver Prototypes –Refine design for production Propagate design to 82 versions (segmentation effects)

12 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 12 SSA Overview Polished Mirror Assembly (PMA) Polished Mirror Segment Central Diaphragm (1 ea.) Moving Assembly (1 ea.) --Whiffletrees (3 ea) --Moving Frame Assembly (1 ea) --Warping Harness Actuators (21 ea) --Lateral Guide Flexure (1 ea) --Tower Assembly (1 ea) --Lock Assemblies (3 ea) --Sheet Flexures (6 ea) Electrical Bulkhead Panel Assembly PRIMARY SEGMENT ASSEMBLY (PSA) Segment Support Fixed Frame Assembly (1 ea) Adjustable Alignment Positioners (AAPs, 3 ea) Actuator Flexure (3 ea) Subcell IMTEC Responsibility Comprises the SSA Removed for Re-coating Mounted Segment Assembly (MSA) Edge Sensors 1 (6-drive, 6-sense) Cables & Connectors for Sensor 1 & WH Optical Coating Actuator 1 1) In WBS, Actuator is part of the M1CS not M1Optics Produced at Optics Shop

13 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 13 Primary Segment Assembly (PSA) Polished Mirror Segment Add Optical Coating, Edge Sensors, Sensor & WH Cabling & Connectors Mounted Segment Assembly (MSA) Add Segment SupportPolished Mirror Assembly (PMA)Include Subcell + Actuators PSA ATTACHED TO MIRROR CELL SSA Overview

14 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 14 SSA Overview SEGMENT SUPPORT ASSEMBLY (SSA)

15 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 15 KEY DESIGN REQUIREMENTS Requirements

16 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 16 Key Requirements (1/4) SSA-Induced Surface Errors: –Goal: Minimize gravity and thermal distortion while controlling cost –Optical performance of SSA evaluated by system level PSS analysis Performed by Project and JPL using IMTEC unit case predictions as inputs –When complete, analysis to consider all SSA distortion effects: Gravity, Thermal Distortion, Thermal Clocking, Polishing, Mfg, + … Assumptions: –Observing segment-zenith angle: -15° to +80° → max Δς = 80° 0° to 65° telescope Zenith ± 15° from M1 curvature –Observing temperature: 9°C (T SITE ) ± 4°C Based on Armazones site testing data (80% of observing time within +/-4C) Alignment & Phasing System (APS) + Warping Harness used regularly to null DC errors - Seasonal mean temperature offset, T mean - Difference between optics shop figuring temp and T ref Single Support-System design, customized for each segment type: –Accommodate shape variations from M1 segmentation (up to 0.5%) No backlash or stick-slip: –Flexure-based mechanisms

17 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 17 Key Requirements (2/4) Accommodate ± 2.5mm actuator stroke: –SSA hard stops nominally at ±3.0mm –Survive full differential tip/tilt Remote-controlled warping harness: –Control 2nd and 3rd order Zernikes: Correction capability: 200 to 2100 nm P-V (38 to 410 nm RMS) Improvement ratio (RMS before correction / RMS after correction) –> 15 on 2nd order terms: focus & astigmatism –> 5 on 3rd order terms: coma & trefoil –Periodic Adjustment: Capability to readjust up to 10 times per night (~1/hour), if necessary Power dissipation <2 Watts/segment –Includes all segment heat sources (Actuators, sensors, electronics, etc.) 50 years lifetime; high reliability: –Only significant wear items are warping harness moment actuators 6-DOF adjustable Subcell & repeatable registration system: –Correct for Mirror Cell tolerances ( ± 5 mm adjustment range, set-and-forget) –Removal/replacement of SSA with ± 50 μm repeatability

18 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 18 Key Requirements (3/4) SSA mass < 90 kg (moving mass < 45 kg) –Not including actuators, segment, edge sensors & cables for edge sensors –Ref: Segment mass ~153 kg for glass ceramic Static stiffness > 12 N/μm, piston: –Assuming rigid actuator & mirror cell Natural frequencies of PSA > 35 Hz with 10N/  m actuator stiffness: –Avoid rotating machinery disturbances at ~25 and ~30 Hz 50 or 60 Hz AC power grids possible –Permit higher actuator control bandwidth –EXCEPT: Torsional modes permitted to be <35 Hz –Unlikely to be excited on telescope –f n >8 Hz required for static stiffness Environments: –Operating conditions such as temperatures, g-levels, etc summary slide to follow

19 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 19 Key Requirements (4/4) MSA shall be compatible with Coating Chamber requirements TBC: –Cleanliness, Outgassing and Coating process compatibility SSA design shall be designed for manufacture –492 units + Spares allows for economies of scale if the design is sound Maintainability and Servicing considerations –Segment exchanges are frequent and must be straightforward Recoating every 2 years implies 5 segment exchanges per week on average Cost control is fundamental to the design –Cost of manufacture and test –Cost of ownership Reliability Maintainability

20 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 20 Environments 1. About any axis in local x-y SSA plane 2. In local z SSA direction (piston) 3. SSA on telescope 4. Scaled up from 1.2m segment loads by a 2 5. Scaled up from 1.2m segment loads by a 3 6. All dynamic loads treated as quasi-static. 1g dead weight not additional QuantityObserving 3 Non-obs. 3 Survival 3 HandlingTransportRecoating Segment Zenith angle 1 (+Z to vert.) 0 to 80°0 to 105° 0 to 135° 180° Temp. and rate of change 0 ± 5°C ± 3°C/hr -15 to 35°C-20 to 40°C-20 to 50°C ≤ 50 °C Humidity0 to 95%0 to 100%0 to 100% condensing - Wind force N RMS TBC N RMS TBC N RMS TBC N RMS TBC 4 -- Wind moment Nm RMS TBC Nm RMS TBC Nm RMS TBC 5 -- Quasi-static load 6 1g1.4g3.0g, any axis TBC 3.0g, any axis TBC 10g, any axis TBC - Altitude m0-5000m m m Tracking and slewing rates El <0.039°/s Az <2.26°/s TBD --- Tracking and slewing accel. El <.00015°/s 2 Az <.00880°/s 2 TBDEl <2.0°/s 2 Az <2.0°/s 2 TBC ---

21 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 21 DESIGN CONCEPT SSA Design

22 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 22 Key Functions of SSA Support segment with minimum distortion (observation mode): –Relative to reference state (as figured) ς SEG = 0°, TREF Ability to position segment in 3 DOFs (piston, tip, tilt): –Continuous, active positioning by three linear actuators Ability to alter surface shape to correct for figuring errors and other effects: –Occasional correction Interface with Mirror Cell Provide means to align SSA in 6 DOFs: –Compensate for mirror cell fabrication tolerances (+/- 5mm any direction TBC] –One-time adjustment during telescope integration Ability to remove and replace MSA with specified repeatability: –Quick replacement of segments without re-alignment of Subcell Accommodate irregular/variable size segments with single support design: –Uniform gaps lead to irregular and/or variable size hexagons Provide means to extract segment out of M1 array for re- coating/maintenance: –Lifting jack –Segment Lifting Talon Interface with segment removal crane

23 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 23 Diaphragm Moving Frame 3 ea Whiffletree Guide Flexure Tower Polished Mirror Segment Axial Support Rod Flexures Warping Harness Actuators, 21ea Edge Sensors (12) Mounted Segment Assembly (MSA) Final Figuring Cam Locks (3ea) Design Concept Note: Does not represent assembly sequence

24 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 24 3ea Actuators 3ea Adjustable Alignment Positioners (AAPs) Fixed Frame Mirror Cell SUBCELL+ACTUATORS Design Concept Actuator Output Shaft Actuator flexure

25 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 25 MSA Placed on Jack Segment Lifting Jack Design Concept Lifting Talon

26 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 26 MSA Attached to Subcell Actuator Flexure Clamped to Moving Frame (3 places) Design Concept

27 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 27 3ea Actuators 3ea Adjustable Cell Interface Fixed Frame Mirror Cell Diaphragm 3 ea Whiffletree Guide Flexure Mirror Segment Axial Support Rod Flexures Warping Harness Actuators, 21ea Moving Frame Tower Cam Locks Released PSA Operational Configuration Design Concept MSA hold-down bolts

28 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 28 PRELIMINARY DESIGN SSA Design

29 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 29 Design Status Segmentation scheme has been chosen: –Scaling rule selected to minimize blank diameter We have a detailed 1.44m Preliminary Design: –27-point mechanical whiffletree axial support –Central diaphragm lateral support –21-actuator/segment, whiffletree-based warping harness –Correction for segment shape variations via custom WT joint locations –Repeatable interface, Subcell alignment, and actuator attachment Extensive, coupled performance modeling has been performed: –Complete FEA revision to reflect Preliminary Design is complete Design satisfies nearly all requirements Completing final changes required for Prototype SSA fabrication Hardware designs being detailed: –Detailed drawings for prototype in process

30 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 30 Current PSA Design PSA attached to mirror cell: Mirror Cell Actuator

31 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 31 Flexures Bonded to Segment Segment Axial flexure assemblies 27 ea. bonded to segment Edge Sensor 12 ea. Central Diaphragm (bonded to segment) Alignment Arrow Points to center of M1 Note: Does not represent assembly sequence

32 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 32 Small Whiffletree Triangles Attached Small whiffletree triangle - 3 inner - 6 outer Note: Does not represent assembly sequence

33 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 33 Large Whiffletree Triangles Attached Large whiffletree triangle Note: Does not represent assembly sequence

34 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 34 Sheet Flexures Added Sheet flexure, 6ea In-plane connection between Whiffletree Triangles and Moving Frame Note: Does not represent assembly sequence

35 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 35 Moving Frame Attached Moving frame Sheet flexure, 6ea In-plane connection between Whiffletree Triangles and Moving Frame V-Groove for lifting, 3 ea. Note: Does not represent assembly sequence

36 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 36 Warping Harness Added Warping harness actuator Warping harness leaf-spring Note: Does not represent assembly sequence

37 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 37 Tower & Locks Installed Tower Assembly with Repeatable Interface Electrical Connector Bulkhead Panel Note: Does not represent assembly sequence

38 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 38 Fixed Frame Included Fixed Frame Note: Does not represent assembly sequence

39 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 39 Installed on Mirror Cell Adjustable Alignment Positioner (AAP) Mirror Cell Actuator Actuator flexure Note: Does not represent assembly sequence

40 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 40 Sector Boundary Sector-F Sector-A PSA’s Clocked 60 degrees between sectors –Two fixed frame versions –Sufficient clearance at boundary Adjacent actuators 35mm nominal clearance

41 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 41 Group of Segments View of Seven Adjacent Segments – Top View

42 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 42 Group of Segments View of Seven Adjacent Segments – Bottom View

43 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 43 AXIAL SUPPORT SYSTEM SSA Design

44 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 44 Axial Support System Two level, 27-point whiffletree system –All-Aluminum design (nearly) Triangles and sheet flexures Aluminum Rod Flexures Stainless Steel Analysis shows high CTE of Aluminum to be acceptable Lower machining costs and corrosion resistance a plus –Triangles nested for compactness Rod Flexures at pivot locations Pivot Flexures at Moving Frame Connection Mirror Support Rod Flexures

45 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 45 Axial Support System Whiffletrees Ride on Moving Frame –Moving Frame: 6061 Aluminum weldment Actuator Rod Flexure Clamp Handling Feature Pivot Flexure

46 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 46 Axial Support System Sheet Flexures: –Concept introduced by SALT –Stabilize whiffletrees in XY SSA plane Pivots (K z ) + Sheet Flexures (K x, K y, R z ) provide 4 Degrees of Stiffness –Tip/Tilt (R x & R y ) remain compliant –Whiffletree mass is nominally balanced about sheet flexure plane –Aluminum 7075-T651, 0.508mm (0.020”) thick Sheet Flexures 2 per WT Pivots 3 per WT Sheet Flexure Attachment to Moving Frame, Typical No further discussion of Sheet Flexures Questions?

47 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 47 Axial Support System 27-Mirror support rod flexures –Invar pucks bonded to mirror using 3M EA-2216 Epoxy Well characterized adhesive JPL heritage for Invar/Zerodur bonds (documented process ) 0.250mm nominal bondline (0.010”) –Stainless Steel rods connect pucks to triangles 304V Cold drawn 94% CW 250 ksi yield strength –Threaded end connections: Stiff, strong, adjustable & removable Vent Hole Vent Hole Mirror Small WT Triangle Invar Puck Flexure: 2.1mm OD x 143mm Long Bondline Detailed discussion: PDR Volume-5

48 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 48 Axial Support System 9-Small whiffletree triangles –Extruded Aluminum: 6061 T6 –Low cost ~$12 per extruded blank, in production qty. 3-Large load-spreader triangles –Cast Aluminum (A356 T51) –Lowest manufacturing cost Complex shapes & large size ideal for casting No further discussion of Triangle design Questions?

49 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 49 Axial Support System Optical Performance –Whiffletree support points and pivot locations determined by optimization –Pivot locations unique for each of the 82 segment types See PDR Volume-2 for details Axial support gravity print-thru: –Figured out at ς seg =0 –Springs-back as [1-cos(ς seg )] –Surface error amplitude ~10 nm RMS (ς seg =90) See PDR Volume-3 for details

50 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 50 LATERAL SUPPORT SYSTEM SSA Design

51 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 51 Lateral Support System Lateral Support Design –Simple Flat Central Diaphragm Low cost Compact (space limited by 45mm thick mirror) –no decoupling flexures –Diaphragm material: Invar 36 (one piece) Baseline for optical performance analysis Prefer to use INOVAR from Imphy Alloys (Fr.) –High purity, w/Low Carbon content Low CTE [~1/2 of regular Invar (0.65 PPM/C)] Better temporal stability –Bonded directly to mirror: Adhesive: 3M EA-2216, 0.250mm bondline (0.010”) Diaphragm dimensions: –Rim OD: 150 mm OD, Hub OD 60 mm –Flexure region: OD 130mm, mm thick 10 mm wide outer rim bonded to glass –Mirror Pocket:  156 mm by 25.5 mm deep Rim t=3mm Central hub t=8.5mm Flexure t=0.350mm Detailed discussions: PDR Volumes-3 & -5

52 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 52 Lateral Support System Diaphragm: Cross-Section View Mirror Segment Moving Frame Diaphragm Adhesive Bond: Diaphragm to Glass Adhesive layer

53 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 53 Lateral Support System Moving frame concept isolates diaphragm Makes operating diaphragm deflections small: High strength material not required Lateral Support gravity print-thru –Lateral support gravity print-thru: –Zero out at ς seg =0 –Springs-back as [sin(ς seg )] –Surface error amplitude ~12 nm RMS (ς seg =90) Diaphragm Attached to Moving Frame Detailed discussion: PDR Volume-3

54 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 54 Tower, Guide Flexure, Locks and Registration SSA Design

55 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 55 Tower & Guide Flexure Tower & Guide Flexure: –Provide lateral load-path for SSA Connect Moving Frame to Subcell (Fixed Frame) –Accommodate segment piston/tip/tilt –Guide flexure details in PDR Volume-5 Tower assembly includes: –½ of the registration interface –½ of the SSA lock system Tower: 6061-T6 Aluminum weldment SSA Lock 3 ea. Guide Flexure Registration 3 ea. at 120 deg Tower Moving Frame (MF) Guide Flexure Attached to MF at ID Guide Flexure Attached to Tower at OD

56 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 56 Tower & Guide Flexure Mirror Segment Moving Frame Guide Flexure Clearance hole for Mirror Support Rod Flexure Attached to MF Attached to Tower Convolution for piston compliance

57 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 57 SSA Locks Locks: –Three per SSA: Secure Moving Frame to Tower –Permanently installed –Enable safe handling, installation & removal –Support segment during actuator change- out –Latched by spring-plunger detent –Hardened cam keyed to handle –Hardened insert mounted in moving frame Cam Spring Plunger

58 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 58 SSA Lock Positions Locked: –Moving frame pushed to “Neutral” position Nominal Clearance mm –MSA can be installed, removed and handled –Actuator can be replaced Unlocked: –Moving Frame and Tower not in contact –Act as Piston/Tip/Tilt hard-stop Nominal clearance +/-3 mm SSA range of travel –outside range of actuator hard stops (+/-2.5mm) Moving Frame No further discussion of Lock design Questions?

59 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 59 Registration Requirements & Goals –Repeatability +/-0.050mm in-plane –Stiff connection in all DOF –Face-to-face axial registration with thru-bolt Strong, stiff and easy to dimensionally inspect Lateral registration features not in axial load path –Sufficient strength to position segments at 14.5 deg inclination during installation 0.25g lateral load plus friction –Cycles: Assume one Installation & Removal per year for 50 years (50 cycles) Implies a near-kinematic design Design concept: –Set of 3 tangential and axial contacts, 120 deg apart –Lateral registration features: Tapered pin in V-groove with small in-plane radial clearance when assembled –Clearance allows Tower to move slightly in X,Y, & Clocking –Axial registration features: Mating flat surfaces clamped by thru bolt –Friction joint during operation

60 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 60 Registration Hardware Tower Separated From Fixed Frame Tower Lowered to Fixed Frame Captive Bolt Tightened to Clamp Joint Registration mating sequence (typical deg) Conical Pin V-groove

61 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 61 Registration Tapered pin: –Material: Ti 6Al-4V Annealed & Nitrided 120 ksi base metal TiN: R c 70 surface coating for galling resistance Insert ring: –Material: 17-4 PH Condition H ksi yield strength Contact stress –Contact force 1009N 210 kg at 14.5 deg inclination with sliding friction coefficient of 0.5 –60 ksi max subsurface von Mises stress FS y = 2.0 Result: –Durable interface that will not Yield or Gall

62 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 62 Registration Pin-Insert clearance: Cost: –Machine shop quote: $400/set, in quantity No further discussion of Registration design Questions?

63 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 63 WARPING HARNESS SYSTEM SSA Design PDR Volume-4 Dedicated to Design and Analysis of Warping Harness

64 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 64 Warping Harness Approach & Architecture Purpose: –Allow automated periodic correction of low order surface distortions: Residual errors from polishing Coating stress distortion Seasonal mean-value of thermal distortion Segment positioning errors within the array (Focus and Astigmatism) etc. Fundamental Approach: –Extension of the Keck design –Re-figure the mirror by bending it in a controlled manner using whiffletree –Bending moments introduced into whiffletree by a set of moment actuators –Actuators are motorized, instrumented and tied into the M1CS Architecture: –21 whiffletree joints are fitted with moment-actuators –Lead screw pushes against an instrumented leaf-spring to create a moment –Stepper motor drives lead screw to permit automation

65 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 65 Design Concept Actuator Schematic –Stepper motor driven screw displaces end of leaf-spring –Strain gauge on leaf-spring provides feedback for motor control –Motors will be mounted on the large whiffletree triangles and to the moving frame Screw Leaf-spring Stepper Motor Nut Strain Gauge WT Joint Flexure (sheet flexure not shown) Axial Support Flexure Large Triangle Small Whiffletree Triangle

66 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 66 Optical Performance Analysis Mx’’ & My’’ Large Triangles, 3ea (Only M  required) Mx’ & My’ Outer Triangles, 6ea M  Inner Triangles, 3ea (M r not required) Actuator Layout –21 Actuators Indicates Applied Moments (Equal and Opposite)

67 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 67 Optical Performance Analysis Actuator Layout –21 Actuators integrated into axial support system Leaf Spring (Typ.) Actuator (Typ.)

68 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 68 SUBCELL SSA Design Fixed Frame AAPs Actuator Flexure

69 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 69 Subcell Design Fixed Frame –Provides a stiff, stable interface between MSA and Mirror Cell –Construction: Welded 6061-T6 Aluminum (2 versions due to segmentation) –Interfaces: Mirror cell (via AAPs) MSA (via tower registration features) Actuators (bolted and pinned joints at ends of Fixed Frame) Segment lifting jack (at center post) See PDR Volume 6 for details –Deep cross-section required to meet 35 Hz for Lateral mode Optimized to reduce mass Fixed Frame Actuator Attachment AAP NEXT SLIDE

70 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 70 AAP Design AAP Requirements/Features –Range of Travel +/-8mm adjustment in-plane –Mirror Cell mfg. tolerances (5mm) plus segmentation effects (3mm) +/-5mm vertical adjustment –Aligned one time during construction and permanently locked/pinned Jam nuts and match-drilled dowel pins –Smooth adjustment (resolution) –30mm post diameter required for stiffness 35 Hz lateral mode –Welded Stainless Steel Post bolted to Mirror Cell –Brass Spherical Nuts –Stainless Steel Spherical Washers –Special tools required to torque assy. Cross Section of AAP Threaded Post: bolted to truss Spherical Nut 2ea. Spherical Washer 2ea. Lock Nut 2ea. Dowel Pins Match drilled at assy. 2 ea. Fixed Frame integration discussed in PDR Volume-6 Alignment budget discussed in PDR Volume-2

71 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 71 Subcell Design Fixed Frame (Top plate removed) Actuator Attachment Castings Jack Center Shaft Support and Bushings See PDR Volume-6 for Jack Design Registration Pins 3 ea. Tower Clocking Pin See PDR Volume-6 AAP attach hole Holes for surveying target holders 3ea. See PDR Volume-6 Jack Center Shaft Guide & Retention Pin See PDR Volume-6

72 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 72 Actuator Flexure Design Overview –Actuator Rod Flexure Design – See PDR Volume-5 for Details Flexible Region: 7.23mm OD x 115mm Long Knurled

73 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 73 Summary: Just Presented: –M1 Overview –SSA Project Overview –Key Requirements –Subsystem Designs Additional Presentations to Follow: –Volume-2: System Level Calculations –Volume-3: System-Level Finite Element Analysis –Volume-4: Warping Harness Design and Analysis –Volume-5: Flexure Design and Analysis –Volume-6: Handling and Integration –Volume-7: Summary and Future Plans Additional Comments & Questions?

74 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 74 Acknowledgements Acknowledgements: The TMT Project gratefully acknowledges the support of the TMT partner institutions. They are the Association of Canadian Universities for Research in Astronomy (ACURA), the California Institute of Technology and the University of California. This work was supported as well by the Gordon and Betty Moore Foundation, the Canada Foundation for Innovation, the Ontario Ministry of Research and Innovation, the National Research Council of Canada, the Natural Sciences and Engineering Research Council of Canada, the British Columbia Knowledge Development Fund, the Association of Universities for Research in Astronomy (AURA) and the U.S. National Science Foundation.

75 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 75 BACKUP SLIDES

76 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 76 SSA Materials Material Properties for Key Components


Download ppt "TMT.OPT.PRE.07.056.REL01 HPS-280001-0105 – Volume 1 – October 24-25 2007 – Slide 1 TMT M1 Segment Support Assembly (SSA) Preliminary Design Review (PDR)"

Similar presentations


Ads by Google