HOW DO COMPOSITE MATERIAL PROPERTIES CHANGE WITH ONE OF THEM UNCHANGED?

A few words about the history and importance of composite materials, dispersed systems with multicomponent dispersion medium and dispersed phase, in the progress of civilization are in the beginning of the paper. This and the methodology of the fields of material properties in the coordinates of composition and process factors, described by experimental-statistical (ES) models, underlie the research presented in this paper. One of the main tools of the methodology is random scanning of "composition-process" fields of material properties. The aim of the work is to show how this tool allows to evaluate the change in properties if one of them should be unchanged, using the examples of solving two tasks in the study of lightweight gypsum concrete, with cenospheres and perlite as fine aggregates. Microsphere size distribution with average about 0.1 mm and average size of perlite grains about 0.3-0.5 mm could suggest rather compact piling and forming relatively steady skeleton. ES-models of the dependences of density and compressive and flexural strength on the content of aggregates and dosages of two chemical additives have been used, built on the results of the designed natural experiment, in which property levels were determined for 18 compositions. In computational experiments the compositions (of filler at fixed average values of admixtures dosages) are generated, and the estimates of their properties by the models allow isoparametric analysis to be performed. In the first example, compositions in which the concrete density level goes beyond the specified boundaries of the isoparametric corridor are excluded from the analysis. Changes in strength are estimated under condition of an approximately constant required density. The strongest compositions under this condition can be assessed. In the second case, the compressive strength must be the required constant. Changes in density and flexural strength under this condition are evaluated based on their levels in compositions remaining in the isoparametric corridor of compressive strength. In this case, the lightest compositions of a given strength can be determined. Isoparametric analysis has proven to be quite useful in materials science.