Difference between revisions of "Statement of Work for the 100% engineering drawings"
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A finite element analysis (FEA) must be performed for all parts that are subjected to strong forces. In particular, the goal of this analysis is to optimize the number and position of fasteners (bolts and brackets) holding the magnet yokes, pole shoes and vacuum box in place, and to optimize the rib structure which stiffens the vacuum box. The design drawings for the dipole magnets shall include two versions: (i) upper and lower magnet yokes consisting of one single piece of iron each, and (ii) upper and lower magnet yokes assembled out of multiple iron plates. | A finite element analysis (FEA) must be performed for all parts that are subjected to strong forces. In particular, the goal of this analysis is to optimize the number and position of fasteners (bolts and brackets) holding the magnet yokes, pole shoes and vacuum box in place, and to optimize the rib structure which stiffens the vacuum box. The design drawings for the dipole magnets shall include two versions: (i) upper and lower magnet yokes consisting of one single piece of iron each, and (ii) upper and lower magnet yokes assembled out of multiple iron plates. | ||
| − | + | Calculations of the magnetic field in the quadrupole and two dipole magnets are required in order to complete the stress analysis. The contractor may chose to carry out these magnetic field calculations independently, or they may rely on the University of Glasgow to compute the magnetic fields based upon models provided by the contractor. The results of the stress analysis will be the basis for defining the machining and fabrication tolerances for the magnets and support structures. | |
| − | The drawing models must be produced in 3-dimensional form using a professional CAD program. Layout and detail drawings will be in 2-dimensional form generated from the 3-dimensional models whenever possible. Input files used for stress analysis | + | The drawing models must be produced in 3-dimensional form using a professional CAD program. Layout and detail drawings will be in 2-dimensional form generated from the 3-dimensional models whenever possible. Input files used for stress analysis and field calculations must be delivered in electronic form. Jefferson Lab will provide a numbering scheme to facilitate their inclusion into the Hall D design database. Further details concerning interfacing with Jefferson Lab’s designing scheme will be provided. |
| − | This statement | + | This statement of work requires that deliverables be received and approved in 3 separate stages. In order to ensure that work remains on track, monthly phone conferences between designers and Jefferson Lab personnel / Hall D collaborators are required. |
| − | + | These meetings, together with the review and approval process at the completion of each contract stage, will be coordinated by a Tagger Design Coordinator to be designated by the Hall D group leader. The work on each stage must not begin until the deliverables from the previous stage have been received and approval granted by the coordinator. The transfer of funds for the ongoing design will follow upon this approval. | |
'''Stage 1 – evaluation and revision of conceptual design drawings''' | '''Stage 1 – evaluation and revision of conceptual design drawings''' | ||
Revision as of 12:20, 8 November 2007
Statement of Work for the engineering design of the Hall-D Tagging Magnets and Vacuum Chamber system
Draft v.2 (11/07/07)
This Statement of Work is to develop detailed engineering drawings and all required material calculations for the Hall D Tagging Magnets and Vacuum Chamber system based on the design goals stated in version 4 of 5/7/07 of the document entitled “Hall D Tagged Photon Spectrometer: Technical Description and Specification” [1] and the conceptual design drawings provided by the University of Glasgow [2], and the Institute for High Energy Physics in Moscow [3].
The scope of this statement of work will be detailed in the following section. A clear separation between the engineering design and fabrication is required according to the procurement rules of the U.S. Department of Energy. The contractor for this statement of work may in the future bid for the contract to manufacture the system, but this expectation is not a requirement.
The Hall D tagging magnets and vacuum chamber system includes the following parts:
- Two dipole magnets including coils and cooling system
- Vacuum box including flanges for thin windows and external supporting structures
- Quadrupole magnet including coils and table support
- Strongback support structure for the dipole magnets and the detector hodoscopes. The design of the hodoscopes themselves is not part of this contract.
The engineering design shall be performed in three stages. Stage 1 collects all of drawings that were produced for the 35% conceptual design together with the revisions that were requested when these drawings were reviewed at Jefferson Lab in May, 2007 [3]. Stage 2 entails a detailed design on the 65% level, including mechanical stress and magnetic field uniformity calculations. In stage 3, detailed drawings of all parts of the system are produced, such that these design drawings can directly be used to manufacture the parts.
A finite element analysis (FEA) must be performed for all parts that are subjected to strong forces. In particular, the goal of this analysis is to optimize the number and position of fasteners (bolts and brackets) holding the magnet yokes, pole shoes and vacuum box in place, and to optimize the rib structure which stiffens the vacuum box. The design drawings for the dipole magnets shall include two versions: (i) upper and lower magnet yokes consisting of one single piece of iron each, and (ii) upper and lower magnet yokes assembled out of multiple iron plates.
Calculations of the magnetic field in the quadrupole and two dipole magnets are required in order to complete the stress analysis. The contractor may chose to carry out these magnetic field calculations independently, or they may rely on the University of Glasgow to compute the magnetic fields based upon models provided by the contractor. The results of the stress analysis will be the basis for defining the machining and fabrication tolerances for the magnets and support structures.
The drawing models must be produced in 3-dimensional form using a professional CAD program. Layout and detail drawings will be in 2-dimensional form generated from the 3-dimensional models whenever possible. Input files used for stress analysis and field calculations must be delivered in electronic form. Jefferson Lab will provide a numbering scheme to facilitate their inclusion into the Hall D design database. Further details concerning interfacing with Jefferson Lab’s designing scheme will be provided.
This statement of work requires that deliverables be received and approved in 3 separate stages. In order to ensure that work remains on track, monthly phone conferences between designers and Jefferson Lab personnel / Hall D collaborators are required. These meetings, together with the review and approval process at the completion of each contract stage, will be coordinated by a Tagger Design Coordinator to be designated by the Hall D group leader. The work on each stage must not begin until the deliverables from the previous stage have been received and approval granted by the coordinator. The transfer of funds for the ongoing design will follow upon this approval.
Stage 1 – evaluation and revision of conceptual design drawings
This assessment includes a list of design drawings, which are part of the conceptual design. Full compliance with the specifications described in reference [1] and the results of the review of this stage are mandatory for further progress. The drawings have to show how internal key alignment parameters are transferred to external coordinates that are to be used for surveying the setup.
1. Top level drawings of complete system including quadrupole, two dipole magnets, vacuum system and strong-back support.
2. Vertical section through a dipole showing how the pole shoes and yoke parts fit together.
3. Top view of a dipole showing the numbers, sizes and locations of the bolts required to hold the structure together.
4. Individual drawings for the pole shoes, top and bottom yokes and back yoke, showing details of bolt locations, flatness of surfaces and tolerances - including the vacuum sealing lips round the pole shoes, and pole profiles.
5. Individual drawings of the pole shoes showing where the fixing holes for taking the vacuum tensioning brackets and the coil support brackets are located.
6. Drawings showing the different types of brackets as required by further refinement of design. For example, the brackets which hold the dipole coils in position should extend over the top of the upper coils.
7. Layout of vacuum chamber showing how top and bottom lids, back wall and output flange are welded together. The input port, the photon beam pipe, and main electron beam output ports shall also be shown.
8. Individual drawings of the top and bottom lids, and the back-wall of the vacuum chamber showing where the fixing holes for taking the vacuum tensioning brackets are located.
9. Top and side view drawings for the quadrupole magnet and its table support.
10. Top and side view drawings for the strong back support for the dipole magnets and fixed-array hodoscope.
11. Drawings showing assembly and disassembly of magnet, including features which allow this sequence of activities. For example, tapped holes for attaching jacking supports to the dipole yokes for use in the assembly and disassembly of the dipoles have to be added.
Stage 2 – Engineering design at the 65% level
The engineering design of the dipole magnet shall be performed including FEA of the energized magnet. Special care has to be taken for the pole shoe design, the attachment of the vacuum box, and torques on bolts such they are not overloaded or stretched. The design drawings for the dipole magnets shall include two versions: (i) upper and lower magnet yokes made out of one single piece each, (ii) upper and lower magnet yokes assembled out of steel plates.
The engineering design of the vacuum box shall be performed including a finite element analysis showing that the rib structure for stiffening the vacuum box is optimized. Special care should be taken for the exact position of electron beam entry port, position and direction of the photon beam pipe, and the position of the exit port for the deflected primary electron beam.
The engineering design of the quadrupole and strongback support structure shall be performed. The engineering design include as well the table support for the quadrupole. The strong back support has to be extended in order to hold the support structure of the fixed-array hodoscope. A stress analysis has to be performed to confirm that the designed strongback allows to hold the magnets and vacuum chamber.
Stage 3 – Complete detailed engineering design
The complete engineering design of the Hall-D tagger magnet and vacuum chamber system shall be performed. The design drawings at this stage shall be directly used to manufacture the parts.
[1] Hall_D_Tagger_Spec_v4.doc (gluex document 821) GlueX_tagger_specification
[2] AutoCAD drawing: Preliminary_drawing_by_Yang and presentations.
[3] IHEP AutoCAD drawings 35%_drawing_by_IHEP_provided_in_April/May_2007
