Re-analysis of European flight load data

WISPER and WISPERX Final definition of two standardised fatigue loading sequences for wind turbine blades

WISPER and WISPERX are standardised variable-amplitude test loading histories for use in the fatigue design of horizontal axis wind turbine blades. They are based on flap load service measurements on 9 different horizontal axis wind turbines, covering a wide range of materials, rotor diameters and geographical locations. The present report is...

The deterministic power-spectral-density-method for linear systems

The Deterministic Power-Spectral-Density-method has been derived directly from the continuous P.S.D.-method. It can be regarded as a "translation" from the frequency domain to the space or time domain. The critical gust profile, giving maximum response, is obtained directly. The D.P.S.D.-method gives the same results as the continuous P.S.D.-...

The response of aircraft to two-dimensional vertical turbulence

Equations for the response of an aircraft to two-dimensional vertical atmospheric turbulence have been derived, both for an aircraft regarded as a continuous system and for an aircraft split up into a number of panels. These equations have been applied to an aircraft model with two degrees of freedom of the size of the Fokker 100, respectively....

Statistical properties of atmospheric turbulence relevant to the calculation of airplane loads

Measured time histories of atmospheric turbulence have been analysed. Distribution functions and exceedance curves of the turbulence and its derivative are presented. The load exceedance curves of various mathematical airplane models due to these turbulence patches have been calculated. Deviations of the properties of these patches from the...

How to generate equal probability design load conditions

This report gives an outline of the method to generate equal probility design load conditions. The various steps are described.

NLR test results as a database to be used in a check of crack propagation prediction models: A Garteur activity

The report describes a joint Garteur activity in the field of the prediction of crack propagation under variable amplitude loading. Existing crack propagation models or models under development will be checked with NLR crack propagation data of 202U-T3 Alclad 2 mm sheet material under F-27 Spectrum flight simulation loading. After completion of...

Gyro noise measurement and analysis

Noise measurements were performed on two identical space qualified gyroscopes of the floated rate integrating type (Perranti Type I25) in an analog rehalance loop configuration of selectable loop bandwidth, running under space representative conditions. The noise frequency range of interest was O.OO5 Hz to 50 Hz. The noise results were processed...

Human pilot describing function, remnant and associated information for pitch attitude control: in flight and ground-based tracking experiments

Servo-analysis techniques, using mathematical models of human control behaviour, are effectively used in studies of the system formed by the human pilot and the flight control system/aircraft combination. Measurement and data analysis techniques for the determination of pilot describing function, remnant and associated information needed in...