Space-Frame Endplate Design and Construction
for LP2 and ILD
Dan Peterson
Laboratory for Elementary-Particle Physics, Cornell University
20110706-LCTPC-Peterson
1
Cornell is building a next generation, space-frame, endplate for LP2.
It is interchangeable with the LP1 endplate delivered in 2008.
20110706-LCTPC-Peterson
2
channeling of mullions
between strut mounts
2011-06-23
space-frame endplate main plate
after first machining step
It is currently at the vendor for
3rd / final machining step.
20110706-LCTPC-Peterson
gas
HV
field cage
termination mount
3
Several studies have preceded this design.
2010-11-11
FEA of ILD equivalent plate design
radius 1.8m, thickness 100mm, material 6% X0
support at inner and outer field cages
deflection = 0.22mm for 2.1 mBar
20110706-LCTPC-Peterson
4
mass
kg
LP1
Lightened
Al-C hybrid
(channeled plus fiber)
Channeled
Space-Frame
material deflection stress
%X0 microns
Mpa
(yield: 241)
18.87
16.9
33
1.5
8.93
8.0
68
3.2
Al 7.35
C 1.29
7.2
(68-168)
(3.2-4.8)
Al 7.35
6.5
168
4.8
8.38
7.5
23
4.2
(strut or equivalent plate)
2010-04-08
Study of space-frame solid model
predicts favorable rigidity/material.
Measurements of existing endplate validate the FEA.
20110706-LCTPC-Peterson
5
Sections of the LP2 endplate
were constructed and measured,
validating the FEA and
demonstrating the equivalence of
the “equivalent plate” design.
20100408
mass
LP1
0.63 kg
20101111
center load
FEA
mm/100N
0.755
20101104
20110202
20110316
center load
center load
center loaded
MEASURED MEASURED MEASURED
mm/100N
mm/100N
mm/100N
0.88
Al-C hybrid ( 1.0 part fiber : 1 epoxy )
Al-C hybrid ( 0.25 part fiber : 1 epoxy )
LP1 (channeled)
0.37 kg
0.75
0.78
1.71
2.12
2.224
2.40
(channeled for the hybrid, but without adding carbon fiber)
space-frame (“strut”)
space-frame (“equivalent-plate”)
20110706-LCTPC-Peterson
0.76 kg
0.111
0.111
0.11
0.12
0.14
6
bolt-on interchangeability with the LP1 endplate
8.4 kg vs. 18.9 kg
144 precision adjustable struts remove machining imperfection build-up.
20110706-LCTPC-Peterson
7
bolt-on interchangeability with the LP1 endplate
Accepts current Field Cage Termination.
Accepts current Module Backframes.
Does not have “fun holes”; must use the mounting holes to the field cage.
20110706-LCTPC-Peterson
8
The LP2 endplate accepts
LP1 2008 Module Backframes.
Revised Mounting Brackets are
being manufactured to
adapt to the LP2 endplate.
Clearance around the strut
mounts is required.
Lightened
Module Backframes have
about 50% mass
and provide more access to
the back of the pad board.
These require a
different Mounting Bracket.
20110706-LCTPC-Peterson
9
Assembly will require a flat plate (shown) and positioning fixtures.
These are in-design, and will go into manufacture in about 2 weeks.
20110706-LCTPC-Peterson
10
Schedule and Costs
Endplates
Backframes-2008
Backframes-Lightened
(Backframes are “3GEMG”, meaning they accept 28mm of
pad board, gas-amplification, gate.)
(2)
(0)
(9)
MountingBrackets (2008 Backframe on LP2 endplate)
(18)
MountingBrackets (Lightened Backframe on LP2 endplate)
(8)
_______________
$58174.43
All parts are expected to be completed by the end of August 2011.
Construction may be completed by the end of October 2011.
20110706-LCTPC-Peterson
11
Previous FEA studies concentrated on
longitudinal rigidity.
This does not directly address our concerns.
More important is the accuracy and stability
of the mounting locations.
One of the endplates will be kept at Cornell
for further testing.
In particular, I am interested in transverse
rigidity and long term stability and if
transverse strain will result in deformations
at other locations.
Future FEA will investigate issues related to
larger modules.
20110706-LCTPC-Peterson
12
Personnel and Funds
Equipment funds
no new funds, I am not saying how much is left.
We are currently requesting another extension beyond July 31.
Salary Funds
expected 3rd year, starting August 31, 2011, ~30-40%
The annual report is accepted (Tuesday); new funds are “pending”.
20110706-LCTPC-Peterson
13