sphenix ohcal mechanics fdr wbs 1.04...recommendation sphenix engineering team response additional...

SPHENIX oHCAL Mechanics FDRWBS 1.04.02

The sPHENIX engineering team

September 17th, 2019

Sept 17, 2019 oHCAL Mechanics FDR 1

oHCAL FDR Introduction

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1. FDR covers sPHENIX WBS 1.04.02 scopeA. Outer HCAL Mechanics: splice plates, pucks and pins, splice plate bolts

• There has been extensive analysis of the splice plates, pucks and pins as well as a study of the arch stability → See presentation from Russ Feder, Dan Cacace and Steve Bellavia

• First article splice plates, pucks and pins have been test fit in to several of the Outer HCAL sectors to verify fit and function→ See presentation from Chris Pontieri and Rich Ruggiero

B. Outer HCAL lift and rotate fixture• A complete Outer HCAL lift and rotate fixture was built, certified, and used for the first few

oHCAL sectors that arrived at BNL. The design has been updated with improvements for safety and function → See next presentation from Connor Miraval

2. Inner Support Ring performance, the mounting of the magnet within the oHCAL barrel and the complete construction plan will be covered in a separate FDR later this calendar year.

Sept 17, 2019 oHCAL Mechanics FDR

Recommendations from Aug 14th Peer Review


To be covered in this WBS 1.04.02 FDR

Recommendation sPHENIX engineering team repsonse

If the issue is not already satisfactorily closed, complete the puck and splice plate buckling analysis and report at FDR.

A report has been developed and will be shown during the Final Design Review. All reports will be made available to the committee.

sPHENIX should proceed with scheduling an FDR of HCAL Mechanics consistent with this report

The team has reviewed the report and will present our responses during this review.

Recommendations from Aug 14th Peer Review


To be covered in Peer Review and FDR for the Inner Support Rings and Magnet Supports

Recommendation sPHENIX engineering team response

Additional oHCAL Sector Assembly Prototype(s): sPHENIX should consider tilting the sector to sector installation test fixture in 912 to the most extreme angle (i.e., “horizontal” orientation adjacent to the “key stone”) to see what it will be like achieve the installation fits at the other extreme of that already tested.

• It will be very difficult to reproduce the conditions we will have in the field. The structural flexibility and positions of sector 30 and 31 are a function of many factors. We don’t think a 12-oclock prototype at nominal position will be very useful compared to the cost.• We are planning a 6-oclock prototype to simulate issues of fit and friction on the lower cradle-base.• Through analysis and planning we understand the issues that may arise during this part of installation.

Inner Support Ring Design: sPHENIX should confirm that mechanical stresses and deflections of the inner support rings prior to and during the installation of the final sector are acceptable, and that the bearing stresses of the inner support ring on the local pads at the HCAL inner surfaces are acceptable.

Agree, This is a relevant concern and the sPHENIX team is taking a close look at the analysis. Will be presented at FDR later this calendar year.

Babar magnet support design: An integrated plan for installing and adjusting the position of the superconducting solenoid cryostat in the HCAL should be finalized and presented, including the design of the axial and vertical adjustment devices, the bearing stresses and deflections in the cryostat and HCAL assembly during adjustment (with appropriate assurances of support and adjustments completed without damage or excessive distortions to the cryostat), the ability to access the adjustment tools in situ, and the compatibility of the added tools and supports with magnetic operation (as these may likely be left in place during operation).

Agree, This is a relevant concern and the sPHENIX team is taking a close look at the analysis. Will be presented at FDR later this calendar year.

• The cradle base assembly that supports the HCAL structure at the bottom is on the critical path for the sPHENIX project.

• There are two new Support Rings that will be used to support the inner surface of the Outer H‐Cal. They are being designed with a box‐beam construction. The rings will be permanently installed in the final configuration.• In the design that was presented, both rings have an opening where the turret would be present,

which is only on one end.• The design includes an inner temporary rectangular plus diagonal cross stiffener, with proposed

adjustment feature not yet designed. This feature is essential to the installation of the final sector, where temporary opening of the deflected sectors on either side is necessary to permit final sector installation.

• Mock Sector installation fit‐checks have been completed using 29 of 32 sectors, i.e., the testing of the method of connecting two adjacent sectors using pucks and pins. For this exercise the sectors are always in a common “vertical” orientation.

• A plan has been developed, analyzed and tested (using the mock sector fit‐check) whereby adjacent sectors are shimmed at intermediate points to maintain parallelism and support some of the weight of the complete assembly. This is seen as a very positive proactive step in ensuring proper sector assembly.

Committee Findings from Aug 14th Peer Review

• Careful assessments have been undertaken to best characterize the Sectors in terms of as‐built holes sizes and location from one end to the opposing end.• Based on a tolerance study (pin to hole across splice plates and sectors and required

differences between pin diameters and hole sizes), there could be as much as a 1/4" inward positional error per side relative to nominal. This would be a total closure of the OH‐Cal (without the Keystone Sector) of as much as 1/2". Efforts are being made to minimize the closure through optimizing pin‐to‐hole relationships as well as the usage of the Support Rings described above.

• Previous expectation was that the assembly would see an additional 1/4" sag due to gravity (without the support rings described above). With the support rings, the sag should be reduced to approximately 0.1“

• The "Pucks" are used to define where the Splice Plate is placed relative to the Sector (with high precision) compared to the "Pins", which are used to define where the next Sectors are located relative to the previously installed Splice Plate.

Committee Findings from Aug 14th Peer Review

oHCAL FDR Documentation: https://indico.bnl.gov/event/6699/

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Stored here:1. All past oHCAL calc reports2. oHCAL mechanics drawings3. Presentations from

1. Jan 31,2018 PRR → https://indico.bnl.gov/event/4133/

2. Apr 5, 2018 PRR Follow Up → https://indico.bnl.gov/event/4501/

3. Aug 14 5, 2019 PRR Follow Up → https://indico.bnl.gov/event/6638/


https://indico.bnl.gov/event/6699/




WBS 1.04.02 oHCAL Mechanics FDR Scope

Sept 17, 2019 oHCAL Mechanics FDR 8

(A) Splice Plate1.5” Thk, 150 ksi AISI 4140HT

(B) Locating Pucks2.75” Dia, 150 ksi AISI 4140HT(C) Structural Pins

2.75” Dia, 150 ksi AISI 4140HT

Outer HCAL sector lift and rotate fixtureOuter HCAL sector connecting hardware

(D) Splice plate bolts4X, ¾-10UNC, Grade 5

(E) Pin and puck

retention washers

(A) Spreader BarRated for sector plus 2x splice plates

(B) Sector end rotation clamp2X, Clamps trunnion and bearing

Trunnion with rotation bearing and indexing plate

View of revised sector endrotation clamp assembly

oHCAL Mechanics Requirements

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1. Connect the 32x oHCAL sectorsa) Maintain adequate safety marginsb) Enable easy installation

2. Maintain Outer HCAL shape a) Shared function with Inner Support Rings

i. Physics: Limit deflection to ~20 mm and protect oHCAL tiles

ii. Clearance between oHCAL ID and cryostat OD = 40 mm

3. Safetya) Buckling analysis and ¾ boltsb) Pin retention washers (during lift or magnetic

event)


(A) Splice Plate1.5” Thk, 150 ksi AISI 4140HT

(B) Locating Pucks2.75” Dia, 150 ksi AISI 4140HT(C) Structural Pins

2.75” Dia, 150 ksi AISI 4140HT

(D) Splice plate bolts4X, ¾-10UNC, Grade 5

(E) Pin and puck

retention washers

Fabrication, receipt inspection and test fitting of the oHCAL sectors is complete→ See following talk from Pontieri and Ruggiero

oHCAL sectors staged for installation of oHCALtiles and wiring on the oHCAL factory floor

All oHCAL sector beams are test fit in a special metrology cradle for receiving acceptance, to evaluate any fit up issues and to help the technicians practice assembly

Splice Plate

Structural Pucks

Structural Pins

The splice plates, pucks and pins are fabricated from high strength steel (AISI 4140 HT) to ensure there is a high safety factor for the oHCAL arch ring structure

10Sept 17, 2019 oHCAL Mechanics FDR

oHCAL Lift-Rotate Tooling Requirements

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1. Safely lift oHCAL sectors during the oHCALbarrel assembly

a) Comply with BNL lift safety requirementsb) Has been load tested...see posted

reports on INDICO page

2. Safely rotate and lock sector to 32 different positions prior to lift → See Connor’s Slides


(A) Spreader BarRated for sector plus 2x splice plates

(B) Sector end rotation clamp2X, Clamps trunnion and bearing

oHCAL Lift-Rotate Testing

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The complete oHCAL sector lift-rotate apparatus was fully load tested and approved by BNL safety in 2019. Improvements to the rotation and angle-selection mechanism were identified during this process.


Redesigned rotation indexing

and locking mechanism

Section through trunnion and rotation

components

April 9-11, 2019 sPHENIX Director's Review 13

Go To Connor Miraval’s Presentations

Splice Plate, Puck and Pins Material selection→ AISI 4140 HT, Min Properties = 350 BHN, 150 ksi Yield

These semi-holes on left side of splice plates wrap around the puck just enough to hold the puck in place in any position

4X Through holes for ¾-xxx SHCS to sector end plates

4X tapped holes for xx-xxx pin retaining washer screws

Outer HCAL mechanics drawings are complete

All of the WBS 1.4 oHCAL “Mechanics” components have been fully analyzed→ Operational Loads Case

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Splice plates, pucks and pins → AISI 4140 HT, Yield = 150 ksi

Peak and average stresses are all well below yield→Max stress ~48.5 ksi at a point where the splice plate bears on the inner puck

Conservative set of operating loads included• Gravity• Seismic acceleration• Magnet, iHCAL and EMCAL dead loads• Ferromagnetic “pressure”• Pole Tip Loads → Don’t exist any more, conservative• Also…There are no shims between oHCAL sectors which allows higher sector

deflections →more load on mechanics parts• Also...There is no friction modeled between the splice plates and the oHCAL sector

end plates →more load transferred through pins

Credit: Dan Cacace

Max stress


Splice PlatesMax Stress: 48.5 ksiF.S. = 3

Pucks and PinsMax Stress: 43.5 ksiF.S. = 3

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Splice plates, pucks and pins → AISI 4140 HT, Yield = 150 ksi

Assembly case loads• Gravity only• No support ring joists included →more load on mechanics parts• Also…There are no shims between oHCAL sectors which allows higher

sector deflections →more load on mechanics parts• Also...There is no friction modeled between the splice plates and the

oHCAL sector end plates →more load transferred through pins

All of the WBS 1.4 oHCAL “Mechanics” components have been fully analyzed→ Assembly Loads Case Credit: Dan Cacace

Peak and average stresses are all well below yield→Max stress ~46 ksi at a point where splice plates pull against outer pins


Max stressSplice PlatesMax Stress: 46 ksiF.S. = 3

Pucks and PinsMax Stress: 36 ksiF.S. = 4

April 9-11, 2019 sPHENIX Director's Review 17

Focus on new Inner Support Rings• All FDR ANSYS models, input files and results and have been independently checked• The version of the inner support rings used for the FDR analysis allowed more oHCAL barrel

deformation → FDR stress results are conservative• New oHCAL structure models are in-work with the new stiffer Inner Support Rings

ANSYS analysis model of new inner support rings The revised ANSYS models

will be used to predict assembly deflections and for

detailed stress analysis of the inner rings and supports

Splice Plate Buckling

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1. Hand and FEA buckling calcs under conservative assumptions show that buckling could be a concern if the splice plates are not stabilized

2. Other conservative hand calcs show that one ¾-10 UNC bolt will provide stability against buckling3. To stabilize plates all plates will have 4X ¾-10 UNC bolts and lock washers. Bolts will be torqued to a pre-

load of 75% yield for the oHCAL sector end plate threads material (AISI 1020)

Calculation By: Steve Bellavia Calculation By: Steve Bellavia

Possible Instability

Possible Instability


Splice Plate Buckling Analysis

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• 4X ¾-10 UNC SHCS and lock washers• Pre-load to 230 ft-lbf torque• Large splice plate clearance holes so

that bolts do not locate the plate

Calculation By: Steve Bellavia

For one bolt there is a S.F.=2


Summary

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1. The Outer HCAL Splice Plates, Pucks and Pins design is complete1. Stress results for the oHCAL mechanics are well below yield and based on very conservative

models that have been independently checked2. An evaluation of the Splice Plate arch buckling stability has been completed and bolts have

been added to ensure stability3. The fit and function of the plates, pucks and pins have been tested on all of the oHCAL

sectors in a series of fit-up tests. Additional assembly prototypes are being discussed to help develop details of the installation procedure.

2. The Outer HCAL Lifting and Rotation fixture design is complete1. An initial version of the fixture was built and fully load tested by BNL rigging experts.

Documentation available.2. Improvements to the function and safety of the rotation features have been implemented

for this FDR3. Additional FEA was performed and checked to confirm safety margins and oHCAL sector

beam deflections.


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