Contribution to the time dependent deformations on the stress (moment) redistribution

Biljana Deretić-Stojanović

For conjugated structures, the basic equations for deformation methods are produced. The influence of normal forces on the deformation is neglected. A structure with fixed nodes is considered, which is composed of rods of type "$k$" and type "$g$". Deformation indeterminate will be only the angles of rotation $\varphi$ of the ends of the rods. Two cases of external influences are considered, that is: a uniformly distributed load and displacement of one end of the rod in the direction perpendicular to the axis of the rod. Bearing in mind the viscoelastic properties of concrete and the relaxation of high-quality steel for the prestressing of concrete, the deformation indeterminate values $\varphi$ and the moments at the ends of the rods are considered as a function of time. Therefore, to represent all the basic relationships, integral equations are used, symbolically by linear integral operators. Thus, an analogy is established with the known algebraic relations of the deformation method for structures from an elastic material. Using the deformation method in the numerical example, the deformation uncertain quantities and moments in the time references $t$ and $t_0$ are calculated. Comparing these values, a significant contribution of temporary deformations to their redistribution is noted.