RFD Cryomodule –

Transportation

Edward Jordan

Thomas Jones

1

Transportation Concept

Optimal position of

load on trailer - to

be determined

2

Design Envelope: 2.6m x 2.2m x 13.3m (HWL)

Transportation FrameLifting eye 4t x 4, SWL =12t• 4 point spreader beam/

defined slinging arrangement

required if off-centre COM

Access ports at

CavoFlex

height to allow

for easy

inspection on

arrival.

Separate bottom panels to be removed for slinging to trailer

bed.

3

CavoFlex arrangement• CavoFlex arranged at 45o

• Optimise vertical position of CavoFlex about COM.

• Need Estimate of COM position from CERN.

• Equivalent Spring stiffness compound of tensile + radial stiffness.

• At excitation, spring stiffness will vary depending upon direction of

travel.

• Vertical Excitation: Alternate between “tensile + radial” //

“compressive + Radial” (spring stiffness not equal in tension

vs compression, characteristic behaviour will not be symmetric

about centre).

• Transverse excitation – Equivalent stiffness equal about

centre (Tensile+Compression+Radial

//Compression+Tensile+Radial)

• Longitudinal excitation – Alternate equal about radial stiffness.

Vertical

Transverse

Longitudinal

?

4

CavoFlexExtract From Cavoflex Catalogue page 30

Compressive load: Arrangement of the wire rope isolators at the height of the centre of gravity (A) ensures high stability and tilting moments are avoided.

For arrangement below the unit (B), i.e. the centre of gravity at a high level, allowances must be made for the occurring tilting moments! The use of additional stabilizers may be necessary (F).

45° compressive load: The advantages of this installation variant (H) are given by the displacement of the main elastic plane towards the centre of gravity. Larger deflections are possible.

5

Chosen Cavoflex Spring

6

CM Interface locations

7

• 12 x interfaces on Left, Right and Bottom OVC

faces, 36 Total.

• STFC interface requirements impact CERN RFD

vacuum vessel stiffness.

• Port locations on CM influence interface

location

• Analysis required to optimise location/ shape

of flange interface

• Shipped under vacuum? Pressure

vessel stress + Mechanical Loads from

shocks.

Transportation Tooling ConsiderationsRemove after warm test/before transit? Can we

qualify without?

Or Transport specific tooling required (not just

gravitational plane re: ELI Dipole failure)

Cantilever load –

requires constraint

and support in XYZ

InstrumentationInstrumentation:

• Slamsticks (no. of?/Location?), Shock clocks for acceptance after transit

(1g/5g/10g).

• Shipped under vacuum or backfilled with nitrogen? Vacuum

instrumentation? Define investigation procedure if shock clocks fail or

vacuum leak.

CM to Spring Interface arms

Welded Steel Box Section Bolted Aluminium Plate

10

CM to Spring Interface arms

Welded Steel Box sectionAdvantages:

• No bolted connections outside flange interfaces.

• Potentially less expensive

Disadvantages

• Susceptible to weld fatigue (consider cycle no.).

• Constrained optimisation options (standard box section & mitre angles etc.)

• Obstructive cross-section

Bolted AluminiumAdvantages:

• Waterjet can create more complex profile (2D)

– Allows for optimisation freedom

• Flange interfaces machined onto parent material.

• No weld distortion

Disadvantages:

• Bolted connections susceptible to backing off due to oscillations after shock/vibration (consider load on joint) (Use Locking Washers)

11

Assembly Procedure

• CM fully assembled and qualified at DL.

• Interface arms attached to CM

• CM Lifted above Transportation frame

• CM Lowered into Transportation frame (Guides required? Or large clearance).

• CM lowered onto feet/pedestal – springs are unloaded during assembly.

• CM lowered via feet adjustment to pre-load the springs

• CM Disconnected from feet/pedestal

• (If CM not assembled to TF at loading area) TF jacked up or lifted on crane to insert skates (pallet lifter?)

• CM skated to loading area.

• TF Jacked up/craned to remove skates.

Reference DesignsSLAC CM transportation to DL

ELI Accelerating Modules to Romania

FEA Method

Transient Results Static Results

FEA Method Maximum Deflection

Transient Static Difference

mm mm %

0.28676 0.26063 9.1

Maximum Stress

Transient Static Difference

MPa MPa %

99.165 90.717 8.5

Observed ~ 10%

difference

between transient

analysis and static

analysis.

For exploring maximum

impulse shock loads –

using a static solve could

be more applicable and

simple (less CPU time).