The equivalent joint loads of the composite member


Biljana Deretić-Stojanović




When calculating conjugate structures by the deformation method, the effects of the external load on the beam are replaced by an equivalent concentric load at the beam nodes. In this article, exact expressions for the equivalent nodal load of a conjugated beam of constant sections are produced, due to the distributed load and concrete compression. They are presented for a conjugate beam with both pinched ends, type "k", and for a conjugate beam with one pinched end and hingedly supported by the other, type "g". Beams have constant sections. With inevitable approximations of the rheological properties of materials, some exist in the conjugated section, these expressions are made without mathematical deviations. Concrete is considered a linear viscous elastic material with the property of aging.In the calculation, the relaxation of prestressed reinforcement was also introduced.The bends were made for the ordinal creep function of concrete.Linear integral operators are used. Suitable transformations of the polysyllabic products of operators that are in the formation of these expressions are provided as linear combinations of operators. Thus, the number of integrations is reduced and the expressions have the simplest form suitable for use. For the familiar creep function of concrete, it is enough to solve three integral equations from which two functions are parametric. Their solution is the functions on which the expressions are linearly dependent.