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FAA fan blade-out certification testing on turbofan engines occurs very late in an engine's development program and is very costly. It is of utmost importance to approach the FAA Certification engine test with a high degree of confidence that the containment structure will not only contain the high-energy debris, but that it will also withstand the cyclic loads that occur with engine spooldown and continued rotation as the non-running engine maintains a low rotor RPM due to forced airflow as the engine-out aircraft returns to an airport. Accurate rig testing is needed for predicting and understanding material behavior of the fan case structure during all phases of this fan blade-out event.
The IIAB iron meteorites are one of the largest iron meteorite groups that formed by fractional crystallization [1]. Iron meteorites formed over a range of oxygen fugacities (fO2)[2], most formed relatively reduced at~ IW–4to –2.5 (IABs), where IW= iron-wüstite buffer, to relatively oxidized at IW–1(IVBs) [2,3]. While the IIABs contain reduced mineral phases (daubré elite [1]),the fO2for IIABs is poorly constrained. The fO2of iron meteorites may have become more reducing during cooling, with oxidized phases (i.e., chromite) forming at higher temperatures and daubré elite forming at lower temperatures [4]. The O-and Cr-isotope compositions of silicates and chromite in meteorites, including iron meteorites, can determine potential genetic links to other meteorite sand con-strain if a meteorite is from the non-carbonaceous (NC) or carbonaceous (CC) group [e.g., 5–8]. Iron meteorite groups have been identified as being in the NCor CC group using Mo[9]and Ni [10] isotope compositions of their metallic component. Numerous iron meteorites contain minor amounts of silicates and oxides [e.g., 11], but most have not been analyzed for their Cr or Ti isotope compositions, with some exceptions (e.g., IIIABs [6,7],a IIG, and a IIAB[7]). We analyzed the compositions of silicates and chromite in six IIAB iron meteorites to investigate the relationship between IIABs and known meteorite groups, the fO2of IIABs, and the origin of chromite in the IIABs. *full abstract in document