A New Look at the Analysis of Coast-Down Test Results

Abstract

A new look is taken at the analytical procedure for reducing the results of the coast-down test. A three-degree-of-freedom model is discussed, and a derivative-based correction algorithm is shown to account for changes in ambient conditions. A parameter optimization technique for coeficient extraction is described, but not validated, due to deficiencies in the available data. The calculation of the standard errors in the extracted coeficients provides the basis for a statistical analysis of coast-down tests. This type of analysis is applied to simulated coast-down data that contain artificial pseudo-random errors, and this leads to a discussion of the accuracy requirements of the coast-down test.