STRENGTH OF ORTHOTROPIC PLATES WITH STRAIGHT AND COUNTERSUNK HOLES

The paper presents the results of computational and experimental studies of the strength of orthotropic plates with free and loaded holes. Various test methods are considered for samples simulating the operation of a structure with a passing and crushing load, as well as samples simulating the combined action of the above loads. Types of samples and loading schemes are presented for various test methods. Experimental studies of the stress-strain state and residual strength of polymer composite materials based on an epoxy matrix and high-modulus fiber have been carried out on samples with free and loaded holes. Approaches are presented to assess the bearing capacity of a single-cut and double-cut joint, taking into account the combined effects of crumpling and passing loads. Finite element models have been developed and calculations for the bearing capacity from single-cut and double-cut joints of orthotropic plates have been carried out. The boundary conditions for modeling a numerical experiment are presented, and the strength criteria used in the course of finite element calculations are described. During the analysis, the reasons for the different behavior and nature of the destruction of samples were considered, and a layered strength analysis was presented. The advantages of studying the bearing capacity of plates and joints under combined loading are shown. Experimental data for various reinforcement schemes are compared, taking into account the combined effect of crumpling and passing load and without it. It is shown that the calculated and experimental results are in satisfactory agreement with each other.