Global Supports Status

1
Global Supports Status

• W.O. Miller, R. Smith, W.K. Miller, G. Hayman, R.
  Baer
• HYTEC
• G. Gilchriese, E. Anderssen, N. Hartman, F.
  Goozen
• LBNL

Outer Frame and End Cone
2
Topics

• Identification of remaining frame issues
• Needs
• Confirmation and finalization of the global
  support frame design
• Need information on outer support tube and
  connection of frame to support tube although
  largely decoupled by plates at end of frame to
  which mounts attach
• Present approach
• Preparation of global support details drawings in
  process
• Updating of the frame dynamic analysis studies
  will be postponed until all information is firm
• Present results of testing with an end cone
  designed for the 500mm dia. Frame
• The easiest item first
• Frame----where we are now and what we are doing
  in the near term

3
Revised Mass Inputs
Updating of the mass information is in process
via Marco
?
?
?
?
?
Changes to 0.52
?
?
?
major addition
Barrels(12) disk services, along the outer
frame up to PPO Current assumption is no weight
sharing with outer support tube
10.4kg
4
Service Ties
Proposed general position of inserts on frame
Also here?
Approximate location of corner splice
5
Frame Dynamic Solutions

• Comments on new mass inputs
• New input agrees fairly closely to what has been
  used in our FE analysis for example the barrel
  services on the end cone per side was 1.29kg, now
  is 1.2kg
• Other individual items used at the CDR agree well
• The new item of 5.2kg per side for services
  (barrel and disks), is shown as along the outer
  frame up to PP0
• Question what is the mass distribution between
  frame and support tube?
• At the present we are holding off on any new
  frame solutions until issues are resolved with
  the integration of the frame with the support
  tube and we need this information by about
  mid-November
• We are, however, proceeding with the preparation
  of the detail frame drawings and the tooling
  design
• Our objective is to prepare for the PRR in
  February 2002

6

• End Cone Developments
• (Sponsored by a DOE SBIR)

7
Development End Cone

• Salient construction points
• End Cone for 500mm frame design
• P30Carbon-carbon facings, 0.44mm
• XN50/cyanate ester graphite fiber honeycomb, 4mm
  thick
• YSH50 quasi-isotropic laminate for outer supports
  and inner tabs
• Static tests
• End Cone is mounted on an optical table, using
  the 8-mounting tabs
• Force is applied and the deflection monitored
  with holographic imaging system

White paint on short tab for holographic
measurements
8
End Cone Components
Cone Bi-panel testing
Panel bonding fixture
Emphasis on correlations with predictions
End cone components
9
Bi-Panel Static Test

• Static Test
• Load application on inner mounting tabs
• Compliance recorded for mounting tab of 17.6mm/N,
  load applied 2.223cm from end of tab
• Slight error noted in fringe counting over large
  deflection range
• Approximately 78mms for 1lbf(4.448N) load
• We note that the fringes are smooth and
  continuous over the Bi-panel joint indicating
  proper structural behavior

10
End Cone TVH Testing

• Static Load Tests
• Concentrated force applied to short and long tabs
• For long tab, force was applied at two radial
  locations
• 1.5875cm, 33.82 ?m/N
• 2.8575cm, two values 16.11 ?m/N and 11.39 ?m/N
• For short tab force was applied at one location
• 0.635cmtwo values 1.733?m/N and 1.767 ?m/N
• Analysis
• Can not explain data for the long tab, force
  applied at 1.5875cm and 2.8575cm, performed on
  separate tabs as well
• For a given tab, deflection does not scale as one
  would expect
• Observations
• However, fringe patterns appear to be smooth and
  continuous, indicating proper structural behavior

Long Tab
Short Tab
11
Long Tab Compliance

• Long tab under increased loading
• Blow-up of fringe region
• We see a very localized fringe where tab joins
  the sandwich
• The localized pattern is suggestive of local
  bending of the facings
• The FE model may be falling short of correctly
  depicting the compliance at this interface
• Current thinking is that we need to improve the
  load transfer in the region of the tab connection
  to the end cone.

Blue lines are the approximate edge of the
sandwich facing
12
End Cone TVH Results

• Results
• Decent comparison between measured predicted only
  exists for the inner short tab
• No reasonable explanation exists at this point in
  time between predicted and measured data for the
  end cone on the long tabs
• Tests were repeated on the long tab at a location
  of 2.8575cm, using dial indicator, and similar
  range in values was noted
• More testing is needed

13
Axial Compliance

• A possible question----how efficient is the
  conical sandwich structure?
• Consider the deflection of a short tab without
  sandwich panels on either side.
• For 1kgf, the strip deflects 0.03268cm, at point
  of load application, a compliance of 33.32?m/N
  (versus 1.733)
• Compliance of a short strip without sandwich
  panels has 19.23 greater compliance.
• Effect of the panels is quite pronounced, which
  is desired

Continuous over the joint
Short Tab
Units cm
Strip only
14
Axial Compliance
Long tab

• Next, look at the deflection of a long strip
  without sandwich panels on either side.
• For 1kgf, the strip deflects 0.09831cm, at point
  of load application, a compliance of 100.3?m/N
  (versus 16.5)
• Compliance of long tab without sandwich panels
  has 6.1 greater compliance.
• Again, the panel effect is substantial

Full cone
Units cm
Strip only
15
Tangential Compliance

• Objective figure of merit for R? compliance
• Load applied to short tab causing a rotation
  about a corner
• Deflection amounts to .0396?m/N or 0.44 ?rad/N of
  rotation at the applied load
• Tangential compliance quoted is for one tab
• For outer shell the tangential compliance goes
  down by factor of 8, with a shell connected to
  all 8-tabs

Units cm
Applied load
16
End Cone Tabs
Short Tab, connected to one shell
Stiffness of tabs will be enhanced to some extent
by connection to the shell, multiple shells in
the case of the long tab
Long Tab, connected to three shells
17
End Cone Summary

• The end cone (500mm dia) tests confirmed our
  expectations
• Axial stiffness of the short tabs is quite
  high-7105 N/m (4011lbf/in) per tab
• Axial natural frequency of the barrel region
  would meet or exceed the 100Hz goal
• However, the analysis of end cone test results is
  still an active SBIR item
• Our desire is to understand what caused the
  deviation between predicted and measured results
  for the long tab
• Simple material tests are planned to ensure the
  appropriate modulus is being used---although this
  is not expected to be a significant contributor
• A further evaluation will be made of the
  connection (FE model) between the sandwich
  structure and the solid laminate
• A design is under consideration that should
  simplify the construction of the joint between
  adjacent flat panels and possibly improve the
  joint load transfer
• With regards to ATLAS, we just need to verify
  that our CAD files properly reflect the interface
  control drawing for Cone A and Cone C.
• We are still on track for the PRR in February
  2002