As indicated in my previous blog, aerospace projects like fighters are using composites at an increasing rate due to technical benefits that traditional metal does not give. To keep up with current demand, the cost research team regularly updates the guidance through processes such as literature review. For the composite literature review, a document written by the RAND Corporation that was derived from Lockheed Martin, Northrop Grumman, Boeing, Sikorsky, and Hexcel data was heavily utilized. Average cost and labor information for completed programs such as the B-2, F-117, F-18, F-22, and V-22 were included as well as concept designs such as the RAH-66. The study compared cost/labor required to manufacture IM7 carbon fiber against the baseline aluminum in 1989, 1995, 1999, and 2005. The data indicated gradual reductions in the manufacturing cost of composites over the 15 year timetable of the study. This is due to technological improvements in manufacturing due to increased use of composites, which the PRICE team attempted to quantify and project to modern day. The data in the study was used to estimate manufacturing complexity for structure (MCPLXS), the measure for cost per weight unit in our estimation software, for each given material type. The study repeated information listings for major cost drivers, which led to the following takeaways:
- IM7 carbon fiber composites around 1989 were about 76-102% more expensive per unit weight to manufacture than aluminum. Today, they are around 23-48% more expensive.
- Major cost drivers include fabrication method and geometric complexity of the part. The degree of geometric complexity is the main restriction on why composites can’t be universally applied.
- Thermosets (epoxy and bismaleimide) cost about the same today. Thermoplastic (PEEK) is about 15% more expensive than thermosets.
- MCPLXS is highly correlated to modulus of elasticity (stiffness). This finding allows more materials to be added to our composite guidance.
- Carbon fiber composites post incorporation with a polymer matrix are about 40% lower in elastic modulus than the fibers themselves.
Review of our prior research also indicates that there are also three other main cost drivers:
- Part Weight Range
- Operating Environment
- Number of Plies
All of this research, and our deep dive work to best understand its uses was utilized to construct a new calculator in the PRICE Cost Analytics® software, which is now in the data validation phase, and testing. More to come!