The interlaminar shear stress analysis of composites sandwich/carbon fiber/epoxy

The current American Airlines Flight 587 Airbus A300 carbon fiber/epoxy composite tail failure has not yet been fully evaluated in terms of material, manufacturing and structural load aspects. The last 10 years the composite tail sandwich structures used: carbon epoxy prepreg systems (BMS 8256 or BMS 8212) for the skin panels and standard Nomex (R)honeycomb (BMS 8124) for the core(1). As was shown in Reference(2) in the process of curing the acting shear forces appeared and created a crush condition. Honeycomb core crush number HCCN is maximized when HCCN approaches 1.0, while at the low level of core crush, the HCCN approaches 0.0. The scheme of forces acting in the core honeycomb is shown in (Figure 1).