*This article was authored by ROBERT YANCEY, JEFFREY WOLLSCHLAGER, COLIN MCAULIFFE, JACOB FISH and originally published in the 2017 Showcase magazine by aerospacetestinginternational.com.
With the application of composites in aircraft structural components, material qualification requirements have been a costly burden on airframe manufacturers. Substantiation of such structures requires analysis at multiple levels of FAA building-block diagram (Figure 1). As one proceeds up the building-block diagram, the number of samples is reduced since structural complexity increases. For example, the greatest number of specimens is usually tested at the lowest level when factors such as batch variability and environment are included in the test. Typically, the number of specimens approaches 1,000 mechanical tests at this lower level. In contrast, only one test article is used at the highest level of the building block diagram (Figure 1), which usually consists of a full-scale test.