MODEL OF STRESS-STRAIN STATE OF THREE-LAYERED REINFORCED CONCRETE STRUCTURE BY THE FINITE ELEMENT METHODS

The object of the study is multi-layer reinforced concrete structures of concrete with various physical and mechanical characteristics of materials - concrete and reinforcement under the influence of loading. Analysis of the stress state of multilayer reinforced concrete beams by using different materials is a complex problem due to the different mechanical and physical characteristics of materials and the cracking behavior of concrete. This article presents an analysis of the stress-strain state of three-layered reinforced concrete structures using the finite element method in the program ANSYS Mechanical. Numerical modeling allows on ANSYS allows combining different combinations of loads, the variability of the strength and deformation characteristics of materials and various types of reinforcement in multilayer reinforced concrete beams. Comparison is made between the experimental results, numerical results and finite element analyses with respect to initial crack formation and the ultimate load capacity of beams. The results of the study were shown that as the grade of concrete in the external layer increases from B15 to B20 and the grade of lightweight concrete in the internal layer increases from B0.75 to B1.5, the crack resistance can be increased by 59.7% and the bearing capacity of the test beam is increased by 16.4%. When the thickness of the external layers varies from 40mm to 80mm, making the crack resistance increased by 47.5% and the bearing capacity of three-layer concrete beams greatly increased by 6.7%. The obtained scientific results enable to determine rational parameters for modeling various structural solutions of multilayer reinforced concrete structures.