Rotor fragment protection program: Statistics on aircraft gas turbine engine rotor failures that occurred in US commercial aviation during 1979

Statistical information relating to the number of gas turbine engine rotor failures which occurred during 1979 in commercial aviation service use is provided. The predominant failure mode involved blade fragments, 84 percent of which were contained. No uncontained disk failures occurred and although fewer rotor rim and seal failures occurred, 100 percent and 50 percent, respectively, were uncontained. Sixty-eight percent of the 157 rotor failures occurred during the take-off and climb stages of flight

Rotor burst protection program: Experimentation to provide guidelines for the design of turbine rotor burst fragment containment rings

Empirical guidelines for the design of minimum weight turbine rotor disk fragment containment rings made from a monolithic metal were generated by experimentally establishing the relationship between a variable that provides a measure of containment ring capability and several other variables that both characterized the configurational aspects of the rotor fragments and containment ring, and had been found from exploratory testing to have had significant influence on the containment process. Test methodology and data analysis techniques are described. Results are presented in graphs and tables

Rotor fragment protection program: Statistics on aircraft gas turbine ngine rotor failures that occurred in U.S. commercial aviation during 1978

This report presents statistical information relating to the number of gas turbine engine rotor failures which occurred in commercial aviation service use. The predominant failure involved blade fragments, 82.4 percent of which were contained. Although fewer rotor rim, disk, and seal failures occurred, 33.3%, 100% and 50% respectively were uncontained. Sixty-five percent of the 166 rotor failures occurred during the takeoff and climb stages of flight

Diffuse Interfaces and Small-Angle Scattering Intensity Behaviour

The contributions corresponding to the Porod, the oscillatory O(h−4) and the Kirste–Porod O(h−6) terms, present in the asymptotic expansion of the small-angle scattering (SAS) intensities, are numerically evaluated, in the presence of diffuse interfaces generated by different smoothing functions (Gaussian, spherical or Helfand–Tagami). It is shown that SAS experiments are generally unable to distinguish among different profiles, because any smoothing can be made to coincide with another type by scaling its thickness parameter. The oscillatory deviations are observable in the Porod plot of the intensities when the typical distance between parallel diffuse interfaces is greater than 50 A and the ratio of the thickness to this distance is less than 1/4. The same conclusion applies to the infinite-slit intensities

Detecting Determinism in High Dimensional Chaotic Systems

A method based upon the statistical evaluation of the differentiability of the measure along the trajectory is used to identify in high dimensional systems. The results show that the method is suitable for discriminating stochastic from deterministic systems even if the dimension of the latter is as high as 13. The method is shown to succeed in identifying determinism in electro-encephalogram signals simulated by means of a high dimensional system.Comment: 8 pages (RevTeX 3 style), 5 EPS figures, submitted to Phys. Rev. E (25 apr 2001

Dynamics of the Destruction and Rebuilding of a Dipole Gap in Glasses

After a strong electric bias field was applied to a glass sample at temperatures in the millikelvin range its AC-dielectric constant increases and then decays logarithmically with time. For the polyester glass mylar we have observed the relaxation of the dielectric constant back to its initial value for several temperatures and histories of the bias field. Starting from the dipole gap theory we have developed a model suggesting that the change of the dielectric constant after transient application of a bias field is only partly due to relaxational processes. In addition, non-adiabatic driving of tunneling states (TSs) by applied electric fields causes long lasting changes in the dielectric constant. Moreover, our observations indicate that at temperatures below 50 mK the relaxation of TSs is caused primarily by interactions between TSs.Comment: 4 pages, 4 figures, submitted to PR

Using Topological Statistics to Detect Determinism in Time Series

Statistical differentiability of the measure along the reconstructed trajectory is a good candidate to quantify determinism in time series. The procedure is based upon a formula that explicitly shows the sensitivity of the measure to stochasticity. Numerical results for partially surrogated time series and series derived from several stochastic models, illustrate the usefulness of the method proposed here. The method is shown to work also for high--dimensional systems and experimental time seriesComment: 23 RevTeX pages, 14 eps figures. To appear in Physical Review