AMS02

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AMS-02

• Coupled Loads Analysis (CLA)

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Reasons for CLA

• Most structures fixed to the USS-02 at multiple
  locations.
• Not an issue in AMS-01 since most of the
  experiment components were mounted directly to
  the magnet, which was a very rigid structure with
  little to no relative displacement between
  interface points. Only Cherenkov Counter was
  mounted directly to the USS-02 with slotted
  connections.
• Loads models for the Lower TOF, TRD, ECAL and
  Radiators were built and incorporated into AMS-02
  model to provide for a more accurate
  representation of the overall stiffness.
• As a check, interface forces of the TRD coupled
  to the USS-02 were compared to the interface
  forces of the TRD alone using the TRD load
  factors from the AMS-02 structural verification
  plan. The interface forces from the coupled
  analysis were significantly higher than those of
  the TRD.
• Given the results of the TRD interface forces for
  the CLA it was determined that all large
  detectors need to be coupled in with the AMS-02
  loads model and checked for increased interface
  loads due to the relative displacement of the
  USS-02 mounting interface.

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Detector Models Used for CLA Analysis

• TRD (Loads model LMSO)
• Upper Time of Flight (Carlo Gavazzi)
• Lower Time of Flight (Carlo Gavazzi)
• RICH (Carlo Gavazzi)
• Radiators (Loads model LMSO)
• ECAL (Loads model LMSO)

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TRD Loads Model With Upper TOF
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Lower Time of Flight and RICH
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Radiator Loads Model
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ECAL Loads Model
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AMS-02 Models Used for CLA

• AMS 6-02a Loads Model was used for TRD and Upper
  TOF and Radiator models
• AMS 11-02 Loads Model was used for Lower TOF RICH
  and ECAL models

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AMS 6-02a Loads Model
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AMS 11-02 Loads Model
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Steps for Structural Verification Using the CLA
Approach

• FEM model is delivered to LMSO.
• LMSO couples the detector FEM model with the
  overall AMS-02 model.
• CLA analysis is run for 128 to 192 individual
  load cases, depending USS-02 mounting location,
  using NASTRAN
• Model is post processed to determine the critical
  load cases based on overall stress. Individual
  internal components including fasteners and shear
  pins are not checked for stress.
• A list of the critical load case stresses,
  interface displacements, and interface forces is
  delivered by LMSO to the individual detector
  developers.

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Steps for Structural Verification (cont.)

• The detector developer assesses analysis results
  and calculates MoS for each component.
• If MoS are negative, design or load factor
  changes may have to be implemented
• New FEM model is delivered to LMSO for
  reiterating
• Process stops once positive margins are achieved

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Current AMS-02 CLA Status

• Upper TOF
• Updated Model Delivered to LMSO (11/02)
• Model coupled with AMS-02 model 6-02a
• 128 load cases completed (64 launch, 64 landing
  full)
• Stresses, interface forces, interface
  displacements, and the model were delivered to
  Carlo Gavazzi Space on (12/9/2002)

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Current AMS-02 CLA Status (cont.)

• TRD M-Structure
• CGS Upper TOF model coupled to LMSO TRD model.
• Model coupled with AMS-02 model 6-02a
• 128 load cases completed (64 launch, 64 landing
  full)
• Delivered Critical Stresses and Beam forces Load
  Cases for the M-Structure along with the USS-02
  interface displacements on (12/10/2002)

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Current AMS-02 CLA Status (cont.)

• Lower TOF
• Model Delivered to LMSO (11/02)
• Model coupled with AMS-02 model version 11-02
• 192 load cases completed (64 launch, 64 landing
  full, 64 landing empty)
• Stress results, including the detector
  displacements, and the model were delivered to
  Carlo Gavazzi Space on (12/10/2002)

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Current AMS-02 CLA Status (cont.)

• RICH
• Updated Model Delivered to LMSO (11/02)
• Model coupled with AMS-02 model 11-02
• 192 load cases completed (64 launch, 64 landing
  full, 64 landing empty)
• Stresses results including the detector
  displacements, and the model were delivered to
  Carlo Gavazzi Space on (12/9/2002)

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Current AMS-02 CLA Status (cont.)

• Radiators
• CLA completed in August 2002
• Will receive the latest radiator model including
  the USS-02 mounting brackets from CGS (date?)

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Current AMS-02 CLA Status (cont.)

• ECAL Uses load factors defined in SVP. ECALs
  mounting interface to USS-02 minimizes the
  effects from the relative displacements between
  interface points.
• All remaining small experiment components are to
  use the appropriate load factors defined in the
  AMS-02 Structural Verification Plan.