After creating the composite estimation method, PRICE® Research is testing the application and receiving feedback from various subject matter experts (SMEs) showed that estimation could possibly be done at a more granular level. Potential other cost drivers that could be added to the solution will be addressed.
So far, the PRICE team has applied the calculator discussed in the prior blog to several components including:
- F-22 pivot shaft
- Canadarm upper/lower arm booms
The F-22 pivot shaft is a key component that controls the horizontal stabilizer. After initial research, the team found a contract that indicated a unit cost of $650k in FY1997 for a batch of 20. The weight range of the part was estimated due to the weight savings indicated in the contract document. The technical source indicated that the pivot shaft was made of 400 layers of IM7 thermoset made by automated fiber placement (AFP).
For the booms, they are key components of the Canadarm system, which is a robotic arm implemented on the space shuttle and International Space Station (ISS). A technical source stated they were each made with 11-16 layers of IM7 thermoplastic made by filament winding (simulated with AFP; “simple” geometry), and they each weighed 23 kg. The reference used for cost is on file from a current NASA consultant.
Modeling the parts in the composite calculator produced 6.24% and 1.03% difference respectively. However, the team wanted to make sure that these results were more than just luck and extended the validation to 7 other test cases. These test cases included a wide variety of items, ranging from golf shafts to gun barrels:
These results indicate that so far, the calculator addresses the major cost drivers well. These results have been shown to multiple interested parties with the feedback being overwhelmingly positive. However, discussions with experts in the industry have shed light on other potential cost drivers:
- Incorporation of vacuum assisted processes.
- Material format. Is it a tape or fabric?
- Curing process. Does the company use an oven, autoclave, or room temperature process?
The most crucial feature the team must add is the ability to combine different composite materials together. Many composite parts are hybrids, with an example being a few layers of AS4, followed by layers of IM7, followed by fiberglass, etc. To accurately model everything in the industry, the information needs to be incorporated in a similar manner to our current “Detailed Calculator”:
These improvements will be addressed iterative-ly in future versions of the composite calculator, and will be used on real life applications as we engage in Uber Elevate Urban Air Mobility projects.