ACD TSA Design –Status Report

15 April 2003Ken Segal

ACD Lead Mechanical Engineer

ACD Panel Procurement Readiness – Apr 15, 2003

GLAST-LAT-ACD

Outline

• Overall Description - Review• TSA Post CDR Updates

– Panel Design, Analyses and Testing– Panel Procurement

ACD Panel Procurement Readiness – Apr 15, 2003

GLAST-LAT-ACD

Shell Design Requirements• No Failure due to Launch & Thermal Loads• Minimum Frequency: 50 Hz, Goal• Shell Mass: 29.8 kg (Calculated)

– Shell w/ Corner inserts & Shell Flexures 37.5Kg• ACD Mass: 271 kg• Attachment to Aluminum BEA

– 4 Flexure Inserts @ Panel Mid-Spans– 4 Flexure Corner Inserts

• Temperatures– -40C to +45C Qualification

ACD Panel Procurement Readiness – Apr 15, 2003

GLAST-LAT-ACD

Shell Design Drivers

• Adequate Real Estate & Suitable Configuration to Mount TDAs

• Sufficient Stiffness & Strength to Limit Vibro-Acoustic Loading and Deflection of TDA Elements

• Isolation of Thermal/Mechanical Loads and Deflections from the BEA

• Minimize Radiation Attenuation • Ascent Venting

ACD Panel Procurement Readiness – Apr 15, 2003

GLAST-LAT-ACD ShellReview

ACD Panel Procurement Readiness – Apr 15, 2003

GLAST-LAT-ACD ShellReview

Aluminum Inserts not Shown

ACD Panel Procurement Readiness – Apr 15, 2003

GLAST-LAT-ACD

Tab & Slot FeaturesReview

ACD Panel Procurement Readiness – Apr 15, 2003

GLAST-LAT-ACD

Construction / MaterialsReview

• Top & Side Panels– Facesheets: 20- mil M46J/EX1522-2, [0/45/90/-45]S– H/C Core 3.1 PCF, 5056, 1”-Thick Sides, 2”-Thick Top– Film Adhesive: FM 73M, 0.045 PSF– Core fill: EY3010, Syntactic Epoxy

• Panel-to-Panel Joints– Mortise & Tenon (Tab & Slot) Features on Mating Edges of Panels– 20-mil Internal & External Clips: Braided Tape Wetted with EA9396– Edge Bonds: EA 9394 Adhesive

• Flexure Inserts– 6061 External Channel/Block Post Bonded with EA9309

ACD Panel Procurement Readiness – Apr 15, 2003

GLAST-LAT-ACD ACD ShellPanel Design Update

• Status– Panel Designs are Complete– Shell Panels Drawings Complete– Panels Procurement Awarded

• Updates Since CDR – Changed from 1522 to 1522-2 Epoxy Matrix– Updated Shell Flexure Inserts to Panel Designs– Updated Tile Flexure to Designs– Analyses Updates Completed

• Facesheets and Doublers• Adhesive Bonds • Aluminum Inserts

ACD Panel Procurement Readiness – Apr 15, 2003

GLAST-LAT-ACD TSA Update -Material Characterization

• Material Changed from 1522 to 1522-2 Matrix. – Better Processing Characteristics on T300 Cloth Prepreg

• Material Being Tested– Flexure Laminate Mechanical Tests– Flexure Consolidation – new Material being tested

• Photomicrographs• Web Mini-Beam-Specimens• Fiber Volume/Void Content

ACD Panel Procurement Readiness – Apr 15, 2003

GLAST-LAT-ACD

TSA Updates-Shell Flexure to Panel

• Shell Flexure Interfaces are Externally Bonded Aluminum Inserts – Panel Design Drivers

• Facesheet Interlaminar Strength• Adhesive Strength• Insert Strength

– Validation: Analyses Completed. • Test coupons to be fabricated and tested prior to Shell assembly.• Problem Mitigation (without impact on Shell Design):

– Facesheet Doublers can be thickened or extended– Corner inserts can be stiffened.

ACD Panel Procurement Readiness – Apr 15, 2003

GLAST-LAT-ACD

•ACD Panel

•Panel Doubler

•Aluminum Insert

•Ti Flexure

Mid Span Insert

ACD Panel Procurement Readiness – Apr 15, 2003

GLAST-LAT-ACD

GRID

Mid Span Design-Side View

ACD Panel Procurement Readiness – Apr 15, 2003

GLAST-LAT-ACD

Corner Shell Insert -Analyses Model

ACD Panel Procurement Readiness – Apr 15, 2003

GLAST-LAT-ACD

Corner Design Loads

• Static Forces from Flexure Blade– Weak Axis Force, 67.31 lbs.– Strong Axis Force, 488.34 lbs.– Axial Force, 344.20 lbs.

• Thermal Forces from Flexure Blade– Weak Axis Force, 147.18 lbs.– Strong Axis Force, 2.68 lbs.– Axial Force, -22.55 lbs.

Typical Results for Corner Doubler

ACD Panel Procurement Readiness – Apr 15, 2003

GLAST-LAT-ACD

Corner Design Loads

Summary of Doubler Stresses– Max Shear (XY Component)

• 1.86E+03psi, Static Reverse– Component Stresses

• X component = 5.11E+03• Y component = 1.21E+04

Margins of Safety– F.S. = 1.5– M.S.(shear) =

– M.S. (compression) = 61.015.1*12100

29200+=−

13.415.1*1860

14300+=−

ACD Panel Procurement Readiness – Apr 15, 2003

GLAST-LAT-ACD

TSA Updates -Tile Flexures

• Flexure Interfaces Moved Away from Panel Edges

• Angled Shims Designed to Mount Angled Tiles.

• Bottom Row Tile is no longer slip stick, but thinned fixed/free flexure.– Repeating Flexure tests for

this design

ACD Panel Procurement Readiness – Apr 15, 2003

GLAST-LAT-ACD TSA Updates –Shell Joint Analyses

• Panel to Panel Joints– Validation

• Test Coupons Made, tested to failure,– used with knockdown factors (per mil-handbook 5)

• Analyses show Positive Margins (lowest is 0.4)– Test Coupon Fabrication is part of Panel

Procurement• Mitigation in the case that vendor cutting looks

suspect during 1st Article procurement

ACD Panel Procurement Readiness – Apr 15, 2003

GLAST-LAT-ACD

Bending Specimen

8.5”

5.5” 3”

4.5 PCF H/C•Moment Allowable

•Based on test results and Mil-HDBK-5 statistical reductions

• 324 in-lbs/in

•Transverse Shear

•87 lbs/in

•Edge Normal

•72 lbs/in

ACD Panel Procurement Readiness – Apr 15, 2003

GLAST-LAT-ACD

In-Plane Shear Specimen

9”

4.5”

3”

•In-plane Shear Allowable

• 182 lbs/in

ACD Panel Procurement Readiness – Apr 15, 2003

GLAST-LAT-ACDPanel Procurement –Plan

• April 24th

– Schedule, Manufacturing Plan, and QA Plan Due• Phase 1

– Demonstrate 1st Article Manufacturing– Manufacturing Readiness Review

• Phase 2– Build Flight Panels and Spares– Perform Panel Fit Checks w/ GSFC– Deliver July 11th to GSFC