Minutes of the Tracker Telephone Meeting
July 28, 2003
- The Pisa group will push on Plyform to get procurements going asap to build a new set of EM sidewalls, using the existing contract. They will inform the IPO with good schedule information within a week, with hopefully some more information as early as tomorrow.
- SLAC will continue the paperwork for an order of 1 set of sidewalls from COI, but a final decision on whether to let the contract for that is pending.
- Erik will discuss with COI the thickness discrepancy on the K13D material. Sandro will get information from Plyform to Erik on the pressure used.
- BJ will revise the sidewall drawings to clarify the number of YS90 plies and to include the aluminum foil. He will not alter the number of K13D layers until those issues are better understood.
- Erik will travel to COI on Wednesday, possibly with Darren, taking the bottom tray SN#1 to try to determine the significance of the damage visible on the bottom face sheet.
- Pisa will ask Plyform to cut coupons from the existing panels for strength and thermal testing (no join testing). Plyform will perform the strength tests to ASTM standards, and Hytec will get the thermal testing done.
Plyform is still looking into detail at lead times for sidewall material delivery to fabricate a new set of EM sidewalls. Sandro said he also asked them to look into getting the YS90 in 150 g/m**2 instead of the present 75 g/m**2 (so that only a single ply is needed on each side).
Sandro said that the initial resin content of the K13D was good at Plyform:
116 g/m**2 with 33% resin mass in the COI report
113 g/m**2 with 35% resin mass measured at Plyform
Plyform first made a 30-layer laminate in 3 coupons. These shows a ply thickness of 86 microns, which agrees perfectly with what they obtained in the sidewall layup as well. Sandro said that they took care to use a relatively low pressure to avoid excessive resin loss. He will try to obtain the exact value used, in facilitate discussions with COI.
Sandro said that the Plyform measurements on completed panels showed 59% fiber volume content, which is close to the specified 55%. Thus resin loss does not seem to explain the discrepancy in the cured ply thickness relative to the COI prediction of 102 microns.
The question came up whether COI has any of this material that they could test in laminates, since their predictions were only based on the prepreg measurements.
Erik said that he will call Heidi at COI and work on resolving the discrepancy between the Plyform measurements and COI predictions.
We decided that it would be prudent to cut and test coupons of the existing sidewall layup, just in case there are surprises in the performance of this material. Hytec will calculate what to expect, given the actual layup. The tests should include material tests performed per ASTM standards. This includes tension, compression, and shear strengths and modulus. Erik would like to see this for the laminate, as manufactured, and for a unidirectional laminate, all zero plies (tension and compression only).
The tests should also include thermal conductance, which will be done by Hytec (subcontracted). The thermal specimen need to be 10cm x 2.5cm, where the 10cm dimension is along the test axis. Erik specified at least two tests in the 0 degree direction and 1 test in the 90 degree direction. Therefore, Hytec will need 3 coupons, 10cm x 2.5cm, for each test, or 9 samples total. This is required to get adequate thickness for the test.
Nanda reported that they have finished integrating the adapter plate to the shaker table and should finish the vibration run on the fixture only sometime tomorrow.