Baranova O. Plywood non-destructive testing with shock-acoustic method.

The thesis is devoted to the actual scientific and practical task of shoсk non-destructive testing method for plywood quality estimation that is based on oscillations theory basic statements and considers the influence of process technological features. Given the analysis of modern wood and and composite materials non-destructive testing methods. Held the analysis of plywood reological properties and investigated the dependancy between the piezo module electric charge and plywood plate mechanical displacement. Improved shock-acoustic method and developed non-destructive testing instrument for plywood. Determined the best parameters for plywood non-destructive testing. Found strong correlation between the ultrasonic method and output parameters of shock method that is harmonic distortions coefficient. Proposed the plywood quality criteria as the number of harmonic oscillations in the main plywood plate oscillation. Determined the economic efficiency of plywood quality control device to locate the plywood inner defects that allow to dicrease the number of personnel in double and save the electricity for 19,8 %.