Determination and extrapolation of the glider load spectra

摘要

Purpose - The purpose of this paper is to present a study on methods for load spectrum (LS) determination and extrapolation, basing on data obtained from experiments. Design/methodology/approach - A sequence of loads registered in flight becomes an object of analysis aimed to calculate full cycles of loads, and on this basis two possible types of LS are determined, i.e. as the transfer array, or in classic form (as the plot presenting appearances of load increments, called "incremental load spectrum"). While the use of incremental LS enables just application of deterministic extrapolation methods, the transfer array enables application of the stochastic method of extrapolation that consists of random redistribution of the transfer array cell values. Findings - The paper presents a comparison between the results of application of deterministic or stochastic extrapolation methods. Attention was focused on the LS registered during thermal flights. The stochastic extrapolation method is less conservative than the deterministic ones, and enables better adjustment of estimated LS to the reality. Originality/value - The novel extrapolation method consists of cumulation of the results of stochastic redistribution of the values in transfer array obtained from the experiment.