SATPC0042406 Tab 04 4 SOW.pdf

Statement of Work- Composite Cryotank Manufacture and Inspection

Objectives: The primary objectives for manufacturing subscale carbon fiber/thermoplastic (TPC) tanks include (1) identify barriers to manufacturing, (2) evaluate consolidation quality, and (3) identify constraints to incorporation of end fittings. Secondary to these objectives is evaluating the benefits of a liner material and manufacturing challenges associated with incorporating the liner.

This activity calls for the manufacture of two composite tanks to address objectives 1-3. In this activity the tanks will be manufactured by in-situ consolidation of T1100/LM-PAEK on NASA/Third party mandrel. Manufacturing a TPC tank is challenging due to the poor drapability of the prepreg material, and the high consolidation temperature requires steel tooling for an autoclave cure process. In-situ consolidation would simplify manufacturing and eliminate the requirement for steel tooling, but remains a low TRL manufacturing approach, oftentimes leading to void content and/or insufficient interlaminar strength of the composite. This exploratory effort will provide information on the feasibility of the approach for TPC tank fabrication. The manufacturing trial will be coupled with non-destructive evaluation to identify voids or delaminations. Finally, two fitting types will be bonded to the tank. One to secure the tank to the test stand, this will be composite. The other to provide fill and drain fittings at the tank end(s), these will be metallic with a seal and doubler anticipated to create a hermetic seal.

The tanks will be manufactured sequentially, allowing time for lessons learned from the fabrication of tank 1 and panel permeation data to be applied to the manufacture of tank 2.

The secondary objective, evaluating a liner, will be accomplished through a series of panel studies. Three flat panels, 12” x 12”, will be manufactured by in-situ consolidation for permeability measurements and manufactured on tooling comparable to that used for tank fabrication.

1- Baseline, as manufactured 2- polymer film coated 3- hybrid coated.

The bondline between the panel substrate and coating shall be characterized by CT scan.

Quantity-

2 composite tanks, 16 plies (2mm) thick tanks as defined below.

3 flat panels, 12”x12”, 16 plies (2mm) thick, as defined below.

Materials-

• Tank walls: T1100/TC1225, 145 gsm

• Mandrel, Tank 1- Supplied by NASA - polymer coated mandrel.

• Mandrel, Tank 2- - Supplied by NASA hybrid liner on mandrel.

Tank Specifications-

• Quantity: 2

• Manufactured by AFP/In-Situ Consolidation

• Tank 1: Manufactured on a polymer coated mandrel provided by NASA

• Tank 2: Manufactured on a hybrid material coated mandrel provided by NASA.

• Dimensions: 18” diameter, 36 – 40” long cylinder, approximately 2 mm thick (16 plies).-

NASA to provide lay-up.

• NASA/vendor shall review dimensions of tank prior to manufacture. (eg., dimensions of length and dome sections).

• Support Fittings: cast stainless steel or TPC tube in mandrel and wind over it so it is wound into the tank (weld thermoplastic to seal from the outside) – this is part of the mandrel manufacturing. Provided by third party with tool- to fit AFP. Vendor shall provide input for attachments required for manufacturing process.

• Fill and drain fittings: dissolvable tool will have fittings embedded into the tool, fittings remain in place when tool melts.

Inspection- 2 tanks and 3 flat panels

NASA/vendor shall hold pre-inspection review and first article inspection review.

• In-process inspection for consolidation

• Post process inspection by Xray CT scan

• Dimensional inspection for thickness variation