Relationships Between Mechanical Behavior and Structure/Properties for Macroscopically Homogeneous Porous Composites Containing Randomly Shaped Filler

ABSTRACT The work focuses on researching relationships between structure/properties and mechanical behavior of porous composites. The primary data comes from tensile testing. The observed properties include elastic modulus, ultimate strength, ultimate strain, and energy need for ultimate strength achievement. The studied materials include composites based on different polyurethane matrices and one rubber filler with various filler and porosity contents. Presented work expands the possibilities of an approach based on measured data fitting by a suitable function followed by obtained parameters interpolation. The utilization of new structural parameters leads to a spatial linear function shape instead of spatial exponential. The newly introduced equation is z c = z m + z m · ( b · p 1 + c · p 2 ), where z c / z m is generally labeled mechanical property value for composite/nonporous matrix, p 1 / p 2 are suitable structural parameters, and b / c are fitting parameters subjected to interpolations by logarithmic function containing values of properties typical for matrices. The work focuses on studying the case of different matrices and one kind of filler. The work includes all potentially valuable interpolations for earlier mentioned properties with the most interesting results in cases of pairs p 1 / p 2 containing two from three parameters: n (porosity), 1 − v m ( v f + porosity), and v f (filler volume fraction).