Space-Frame Endplate Design and Construction for LP2 and ILD Dan Peterson

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Space-Frame Endplate Design and Construction for LP2 and ILD

Dan Peterson Laboratory for Elementary-Particle Physics, Cornell University

20110706-LCTPC-Peterson


Cornell is building a next generation, space-frame, endplate for LP2.

It is interchangeable with the LP1 endplate delivered in 2008.


gas

HV

field cage termination mount

channeling of mullions between strut mounts

2011-06-23space-frame endplate main plateafter first machining step

It is currently at the vendor for 3rd / final machining step.


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


2010-04-08

Study of space-frame solid model predicts favorable rigidity/material.

Measurements of existing endplate validate the FEA.

mass material deflection stress kg %X0 microns Mpa (yield: 241)

LP1 18.87 16.9 33 1.5

Lightened 8.93 8.0 68 3.2

Al-C hybrid Al 7.35 7.2 (68-168) (3.2-4.8) (channeled plus fiber) C 1.29

Channeled Al 7.35 6.5 168 4.8

Space-Frame 8.38 7.5 23 4.2 (strut or equivalent plate)


20100408 20101111 20101104 20110202 20110316 mass center load center load center load center loaded FEA MEASURED MEASURED MEASURED mm/100N mm/100N mm/100N mm/100N

LP1 0.63 kg 0.755 0.88 0.75 0.78

Al-C hybrid ( 1.0 part fiber : 1 epoxy ) 1.71Al-C hybrid ( 0.25 part fiber : 1 epoxy ) 2.12

LP1 (channeled) 0.37 kg 2.224 2.40 (channeled for the hybrid, but without adding carbon fiber)

space-frame (“strut”) 0.76 kg 0.111 0.11 0.12space-frame (“equivalent-plate”) 0.111 0.14

Sections of the LP2 endplate were constructed and measured,

validating the FEA and

demonstrating the equivalence of the “equivalent plate” design.


bolt-on interchangeability with the LP1 endplate8.4 kg vs. 18.9 kg144 precision adjustable struts remove machining imperfection build-up.


bolt-on interchangeability with the LP1 endplateAccepts current Field Cage Termination.Accepts current Module Backframes.

Does not have “fun holes”; must use the mounting holes to the field cage.


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.


Assembly will require a flat plate (shown) and positioning fixtures.These are in-design, and will go into manufacture in about 2 weeks.


Schedule and Costs

Endplates (2) Backframes-2008 (0) Backframes-Lightened (9) (Backframes are “3GEMG”, meaning they accept 28mm of pad board, gas-amplification, gate.)

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.


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.


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”.

Documents

Space-Frame Endplate Design and Construction for LP2 and ILD Dan Peterson