Effects of plastic hinges on partial interaction behaviour of bolted side-plated beams

Abstract

a b s t r a c tSlips of mechanical connectors in steel plate reinforced concrete (RC) structures can significantly affect the load-carrying capacity of the structures. The difference in deformation between the steel plate and the reinforced concrete counterpart is known as partial interaction. In this study, the flexural behaviour of bolted side-plated (BSP) reinforced concrete beams was investigated experimentally. Two new deformation-based parameters, namely the strain factor and curvature factor, were introduced to quantify the degree of partial interaction between the RC beam and the steel plates. The experimental results revealed that the degree of partial interaction between RC beams and steel plates could be reduced by as much as 50% when the BSP beam proceeded from a linear to a non-linear stage in which plastic hinges have formed in critical sections. Consequently, the load-carrying capacity was reduced by up to 30% of the theoretical additional strength provided by the bolt-plate system, which is more than double the allowance proposed previously in the literature. The under-estimation of the effect of partial interaction in composite structures can result in unsafe design.

Experimental Study on the Flexural Behavior of over Reinforced Concrete Beams Bolted with Compression Steel Plate: Part I

“…These beams consisted of two or three layers of diverse concrete strength levels. This range of strength could be seen from the top section made of high strength concrete (HSC), with a bottom layer, which was made of normal strength concrete (NSC) [10], and an external bonding with a steel plate in the side of the RC beam [11,12]. The steel plate bonding in compression was the current method.…”

“…Modes of failure and crack patterns of over-reinforced beams with a side-steel plate (a) SBSP and (b) SBWP[12].…”

An Experimental and Numerical Study on the Flexural Performance of Over-Reinforced Concrete Beam Strengthening with Bolted-Compression Steel Plates: Part II

“…It is also known to have high stiffness. In general, the plates are bonded/glued to the beams and attached at the compression and tension zones of the RC beams to provide a locking mechanism that will increase the load-bearing capacity and ductility of the section in order to avoid brittle failure [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15].…”

Design of bolted side-plated reinforced-concrete beams with partial interaction

“…A variation on the formulation of the Ritz method using linear combinations of harmonic functions was adopted for the consideration of the plate local buckling coefficients (Smith et al, 2000;Su et al, 2010). Siu and Su (2009) and Su and Siu (2007) developed numerical procedures for predicting the non-linear load-deformation response of bolt groups, and proposed an analytical model by introducing Newmark's model (Newmark et al, 1951) to solve the longitudinal partial interaction of BSP beams under several symmetrical loading conditions (Siu, 2009;Siu and Su, 2010). Su et al (2014) further extended this analytical model to handle more complicated asymmetrical loading conditions.…”