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).