A refined R.C. beam element including bond–slip relationship for the analysis of continuous beams

Abstract

In this paper a refined fibre model is proposed for analysis of R.C. beams that include an explicit formulation of bond–slip relationship. The model is introduced in a matrix formulation developing a computational method for statically indeterminate beams. The method takes into account detailed models of materials and their interaction so that a reliable analysis of non-linear behaviour of the R.C. beams can be obtained including debonding of rebars, width of cracks, tension stiffening effect and so on. The capability and the reliability of the procedure have been tested by means of a large theoretical–experimental comparison and a meaningful case is described as an example in the paper. The procedure is very efficient in terms of computational effort and convergence velocity, moreover it is general and allows a refined non-linear analysis to be effected for a design purpose without simplified hypothesis in the rotational capacity of the element. The model requires only the introduction of the geometrical characteristics of the element and the constitutive properties of the materials and allows the local behaviour of R.C. beams to be studied in details due to the bond interaction between steel and concrete.