Seminar - Gianluca Ranzi - Analysis of composite beams with partial shear interaction using the direct stiffness approach
Wednesday, April 7, 2004, 1.10 - 1.50 pm
Civil Engineering Lecture Room 3
Steel-concrete composite construction has been gaining popularity over the last century thanks to its ability to well marry the advantages of structural components made of concrete and steel.
This seminar will focus on the behaviour of composite beams with partial shear interaction. A model has been derived for the analysis of m-layered composite beams in the linear-elastic range (where m is an integer greater than or equal to two). This model is then applied to the particular case of composite beams formed by two layers, as in the case of steel-concrete composite beams. Based on this model, a direct stiffness approach is formulated and closed form solutions are derived for particular structural cases.
The direct stiffness formulation is extended to account for material nonlinearities and the proposed nonlinear modelling technique is validated against experimental data available in literature.
The behaviour of composite beams with partial shear interaction is then investigated accounting for time effects such as creep and shrinkage. The model proposed in the linear-elastic range for two-layered composite beams is further developed to account for these time effects and closed form solutions are derived for some structural systems. In addition, the applicability of the direct stiffness approach is extended in the time domain. The use of the direct stiffness approach requires only one discretisation to be carried out, which occurs in the time domain, instead of the two (i.e. one discretisation in the time domain and one discretisation along the beam axis) required by modelling techniques available in literature. The time-dependent behaviour of the concrete is modelled by means of the algebraic methods, such as the age-adjusted effective modulus method and the mean stress method.