Load–deformation prediction for eccentrically loaded bolt groups by a kinematic hardening approach

The use of steel plates anchored on the sides of beams is effective in strengthening existing beams when they have deteriorated. The behaviour of the side plated beam is highly affected by the level of partial interaction between the components, which is provided by the use of bolts acting in groups. To determine the structural response of composite beams, the interaction through bolts or the load deformation response of bolt groups should be modelled. This study aims to develop a procedure to predict the non-linear load–deformation response of bolt groups subjected to combined in-plane moment and shear. The in-plane behaviour of bolts is first established by adopting the analogy from material plasticity. Then the incremental load–deformation responses of bolt groups are derived. Numerical examples are carried out and the results are verified by the available experimental results. The theory developed herein is able to model the load–deformation response of bolt groups and can potentially be applied to non-linear analyses of bolted side plated structures.