ALTERNATIVE CALCULATION OF BUILDING STRUCTURES BASED ON ROTATIONAL MOMENT

Abstract

Modern design of building structures of buildings and structures requires alternative methods of calculation. By comparing different calculation methods, the correctness of the design for structures is checked. Based on the concept of the moment of rotation, its differentiation by the height of the cross-section, a method of calculating deformations and stresses in the crosssection of the beam structure was found. Such a calculation can serve as an alternative, verification one in the design. Also, this calculation method can be the main one. Differential dependences of the rotational force moment are derived along the section height to determine the longitudinal force and distributed load in the cross-section. The study proved that the differential from the rotational moment along the height of the section h is the longitudinal force, and the differential from the longitudinal force N on the height of the section h is the distributed load. It is also shown that it is possible to represent the distributed load on the end of the beam q as a second-order differential from the rotational moment. For the convenience of calculations, the author has developed a table for finding the result of multiplying the epures of rotational moments of cases common in practice. As a test example, a longitudinally compressed beam loaded by two concentrated vertical forces in the thirds of the span is considered. To check the proposed design apparatus, the values of stresses and deformations were compared with those determined in the traditional way. According to the results of calculations, the stresses and deformations calculated according to the proposed method and traditional one are identical. This confirmed the validity of the proposed calculation method that uses the rotational moment as the initial criterion. Thus, the classical parameter of the rotational action of forces – the moment of force at a point, together with the traditional parameters: bending moment and normal force – can be used to calculate stresses and deformations in the cross-section of the structure and obtain accurate calculation results. It is proved that deformations and stresses in the cross-section of the beam structure can be determined based on the rotational action of forces. The use of the proposed design apparatus allows checking existing calculations and performing structural calculations for a new project in construction.