The physicomechanical characteristics (PMC) of foam plastics (FP) vary over a broad range not only for the different composite compositions and fabrication processes employed for the production of articles, but also within the limits of chemically homogeneous groups [i-3]. Complete utilization of the potential of FP with minimal outlays is ensured by combined efforts of builders and technologists in designing the component and during its fabrication [i]. During the formulation of foamed plastics, the lower the average apparent density, the lower the initial heating temperature of the mold, and the higher the rate of heat removal from the surface of the article, the greater the macroheterogeneity. The character of the macroheterogeneities has undergone considerable experimental investigation [i-4], but the literature contains no systematized data on functional relationships between PMC and the above-indicated parameters. Laws governing the density distribution over the thickness of the plastic, especially the panels of enclosures, have been thoroughly investigated [4]. Density distributions for two FP formulations are presented in Fig. i: Grade PPU-317 foam polyurethane and Grade FRP-I phenolformaldehyde FP. Note that the lower the mold-heating temperature, the more clearly the integral properties of the FP are expressed, i.e., an increase in homogeneity, as a rule, requires additional energy outlays and complication of mold design. Idealization in the form of multilayer, or, more frequently, a three-layer system is widely used in designing plates and panels of integral foam plastics (IFP). This schematization does not always ensure sufficient accuracy for evaluation of the stress-strain state (SSS).