Numerical and Experimental Study of Multilayered Cylindrical Bodies With Local Bundles

Abstract

A numerical and experimental study of the regularities of the influence of the most likely defects such as local bundles inside multilayer cylindrical large-sized housings on the deformation and strength characteristics of the housings near their end connection is carried out. A statistical analysis of discontinuities in the manufacture of holes for pin-pin connection at the front and rear junctions of the joint is carried out. To form a sample, the results of accompanying passports of more than 200 build-ings were processed. Based on the results of ultrasonic flaw detection, the areas of discontinuities at the front and rear junctions of the joint were determined, and as a result of statistical processing, diagrams of the distribution of discontinuities were con-structed. Physical models of cases in the form of multilayered cylindrical rings with the presence of probable defects in the structure such as local bundles are made and, further, to conduct ring tests according to the standard method to study the effect of local bundles on the deformation and strength characteristics of the ring. The relationship between the relative strength limit and the coefficient of discontinuity (delamination) of the composite structure of the ring is established using the obtained exper-imental data. A defect in the form of a bundle, on the one hand, leads to a decrease in the mechanical characteristics of the ma-terial, and on the other hand, leads to a concentration of stresses in the bundle zone. The total effect of stratification is ex-pressed in an increase in the corresponding stresses that characterize the state of the loaded structure, and, accordingly, a de-crease in its load-bearing capacity. A mathematical model is developed and numerical modeling is performed on its basis.