Simulation of concentration of an admixture in the multiphase layer with random spherical inclusions

The diffusion of an admixture substance in a multiphase layer with randomly disposed spherical inclusions was investigated. The solution of the initial contact-boundary value problem is obtained in the form of the integral Neumann series. Computer simulation was performed based on the obtained calculation formula. Main regularities of the distributions of the averaged admixture concentration in the layer depending on the values of the diffusion coefficients, density and volume fractions of inclusions were established. The influence of the number of phases of the porous body on the diffusion processes in a multiphase layer with a uniform distribution of spherical inclusions was determined. The dependence of the increase of the averaged concentration function on the characteristic radii of spherical inclusions was analyzed, in particular, it is shown that the behavior of this function does not depend on the ratios of the reduced diffusion coefficients.

Application of Concept Design in Structural Design Software

Concept design is the heart and soul of structural design. Combining with applications of PKPM series computer construction structural CAD system software, the paper described that software has some applicability, limitations, and approximate in practical construction applications. The structural design personnel should start from structural concept and par more attention to value of calculation parameters, computing model processing and calculation results determination, so as to ensure safety, economy and rationality of structural design.