The indirect measurement of tensile strength for a higher temperature by the new model IGDMC(1, n)

Abstract

A new prediction model, the interval grey dynamic model by convolution integral with the first-order derivative of the 1-AGO data and n series related, abbreviated as IGDMC(1, n), is presented in this paper. Improvements upon the existing grey prediction model GM(1, n), Grey Model with the first-order derivative of the 1-AGO data and n series related, are made to a large extent and the messages for a system can be supplied sufficiently. The relationship between input series and output series is constructed sufficiently by IGDMC(1, n) and high accuracy of indirect measurement or prediction for a dynamic system can be broadly anticipated. A measure for assessing the reliability of the predicted values is required and a common approach is through the use of prediction intervals. These are the upper and lower confidence limits of the predicted values. The relationship between the tensile strength and Brinell hardness number of a material is very intensive, but a definite explicit or implicit function of them does not exist. The mechanical property of a material may vary with the chemical ingredients and the procedures of heat treatment and it is a grey system. It is more difficult to measure the tensile strength than the Brinell hardness number of a material especially for a higher temperature. The point and interval indirect measurement of the tensile strength of a material for a higher temperature can be made by IGDMC(1, n) with Brinell hardness number of the material acting as the leading indicator. The results show that the accuracy of the indirect measurement of the tensile strength is satisfactory.