NASA_RFQ_80NSSC18Q0569_RDSS.pdf

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NATIONAL AERONAUTICS AND SPACE ADMINISTRATION

NASA SHARED SERVICES CENTER

RECOMMENDATION AND DETERMINATION TO SOLICIT FROM ONE SOURCE

OR BRAND NAME

PICK ONE

Sole Source:

☒I recommend that NASA, NASA Shared Services Center negotiate with Trueflaw Ltd. only for a set of radiographic special nondestructive evaluation (NOE) capability demonstration test samples. The total estimated cost of this effort is $60,000 and the estimated period of performance or lead-time for delivery is 12 Weeks.

This recommendation is for the acquisition of supplies or services determined to be reasonably available from only one source/only one manufacture. Competition is impractical for the following reasons (please answer the questions below):

1. What are the reasons for soliciting only the suggested source/suggested brand name? Please provide the unique characteristics of the items or services along with the supporting rationale and the market research performed to substantiate your reason for the suggested source/brand name.

The Materials and Processes Branch (ES4) Nondestructive Evaluation (NOE) Laboratory requires a set of 0.030 inch thick test samples containing thermal fatigue cracks for special NOE capability demonstration testing of radiographic inspection equipment and personnel in accordance with NASA- STD-5009. Fracture control requirements mandate that inspectors undergo a special NOE capability demonstration test to verify that they can reliably detect the smallcracks that could lead to catastrophic failure of flight hardware. Radiographic inspections of the welds in composite overwrapped pressure vessel (COPY) liners play a critical part in the implementation of fracture control methodology.

Current COPY designs are incorporating ever thinner metallic liners which drives the need to reliably detect ever smaller cracks.

The existing test samples used for radiographic special NOE capability demonstration tests were fabricated using mechanical load test machines to apply alternating stresses to plates that have been notched to initiate controlled fatigue crack growth at chosen locations. After load cycling, the plates are machined to remove the starter notches while leaving behind the fatigue cracks. In order to accommodate the necessary starter notches and handling by mechanical load test machines, the plates must be significantly thicker than the final test samples. Apart from the expenses incurred for reducing the excess thickness, removal of the starter notches alters the natural shape and, most importantly, reduces the depth of the fatigue cracks left behind in the final test samples. In the case of radiography, the depth of a fatigue crack as a percentage of the sample thickness is the primary measure of the crack size that can be reliably detected.

As the size of the required fatigue crack decreases, the depth of the starter notch becomes a greater percentage of the crack's depth. For COPY liners that are 0.030 inch thick, radiography must detect cracks with depths as little as 0.018 inch (0.6t). Even the smallest practical starter notch of 0.005 inch deep would represent roughly a third of the needed crack size. Growing a longer and deeper crack to allow for removal of the starter notch is less than ideal because the crack left behind will have a different, unnatural, shape and a different probability of detection.

Trueflaw's propriety thermal fatigue method for fabricating capability demonstration test specimens does not require a starter notch. Therefore, Trueflaw avoids the issues associated with removal of the starter notch and can provide naturally shaped fatigue cracks in very thin test samples.

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2. What is the impact to the government if another vendor/brand is used? Include any dollar, schedule, or compatibility impacts if possible.

Any course of action other than awarding to Trueflaw Ltd. would not fulfill the Agency's requirements, and therefore, is not in the best interest to the Government.

The existing set of 0.1 inch thick test samples was manufactured in 2015 by Jacobs at cost of $2, I 97 .80 per sample. In contrast, the estimated cost of this effort is $1,090.91 per sample. Jacobs was contacted for this effort but declined to provide a quote. The Statement of Work was also sent to Element Materials Technology, the only other known commercial vendor for this type of test sample, but they have not responded. No other vendor was found that could manufacture the required test samples.

ADDITIONAL COMMENTS:

AJAY KOSHTI 05/02/2018

Technical User Name Date

AST, MECH MATERIALS & STRUCTURES

Title

ES411

Office