This article describes a method of stepwise calculating the optimum area of reduced constructive steel I-section, which is one of the supporting components of the normal rectangular section the composite steel-concrete beams, with subsequent verification of their ability to carry the load. In the first step of design carried out calculations the area and selection of a rational section I-component the normal section of composite (steel-concrete) beams, depending on its height and strength characteristics of materials. In the second step using the proposed dependencies is determined stress-strain state of a received normal beam section that will match given boundary relative deformation at the time of destruction. In the third step cross-section of the beam, which has been previously taken, verified for strength depending on the its stress-strain state at the time of destruction. The proposed method makes it possible to improve separate provisions of the rules for the design and calculation of composite beams, which are included in section 6 of Eurocode 4 and directed by solving practical engineering tasks.

Предложено методику расчёта оптимальной площади конструктивного приведенного стального двутаврового профиля (КПСДП), которым армируется нормальное прямоугольное сечение сталебетонных балок (СББ), базирующейся на основных положениях деформационной модели.

Запропоновано методику розрахунку оптимальної площі конструктивного приведеного стального двотаврового профілю (КПСДП), яким армується нормальний прямокутний переріз сталебетонних балок (СББ), яка базується на основних положеннях деформаційної моделі