Analiza uticaja reoloških svojstava kod složenih spregnutih konstrukcija slojevitim konačnim elementima
DoktorandCumbo, Anđelko P.
Članovi komisijeStojić, Dragoslav
MetapodaciPrikaz svih podataka o disertaciji
This paper contains a proposed numerical procedure for determination of stress and deformations state due to creep and shrinkage of concrete and relaxation of prestressed steel in composite structures with apply of the finite element method. Stiffness matrix of linear finite-element is performed by use of layers technique, but rheological properties of concrete and prestressed reinforcement are introduced by fictive loading. For procedure development, generalized incremental stress-deformation links are used for viscous materials derived by application of displacement method. The manner is analysed in more details to determine fictive forces due to viscous deformations, especially the axial forces part as a contribution from the pure member bending. Improved procedure is formulated which provides considerable correction of results accuracy without the need of structure discretization on the bigger number of finite elements. Here developed procedure for calculation of composite struct...ures is applicable in various technological procedures of construction-work with enabled gradual inclusion of some individual parts of composite section into a stress active section. It has been shown that time - dependent (rheological) changes considerably change state of stress and deformations of CS and that in their design negative impacts cannot be left out of the analysis. To that aim, the author has developed a program package with whose application, it is simple to get the needed results.