Simulation of nanomodified polymers testing by the electric capacitive method
At present, the issue of the electric capacitive method application for non-destructive testing of nanomodified polymer composite materials (NMPCM) is relevant. The paper gives a mathematical model based on Maxwell-Ampere, Faraday and Gauss’s equations and satisfying the Dirichlet boundary condition. This paper proposes a computer simulation of the nanomodified polymers testing by the electric capacitive method. The simulation was carried out in a two-dimensional planar formulation and a minimum required density of the calculated grid was determined (37,300 elements) to obtain a qualitative result of the calculation. A number of numerical studies were conducted with different contents of CNT in NMPCM in the range of 0 wt % up to 10 wt %, different defect depths in the material and distances from the sensor to the surface. The homogeneity of the dispersion is estimated using the Cochran statistical criterion. The value of the Cochren criterion did not exceed the critical one for all conducted experiments. Approximation relations of the maximum defect depth and distance from the sensor to the surface were obtained depending on the content of CNT in NMPCM. The results of the studies allowed determining the limits of the method application in the testing of NMPCM. The maximum defect depth was 5H (H is the relative value of the defect) at the CNT concentration of 1 wt % and with increasing the CNT concentration, the maximum defect depth decreases to 2H. The maximum distance between the sensor and the surface was 0.33H at the CNT concentration of more than 5 wt %. The obtained data can be used in the design of technological equipment for the polymeric nanocomposites production