Validation and application of bearing and block tearing resistance; background to prEN1993-1-8:2021

Abstract

An investigation of bolted connections with a specific geometry and bolt arrangement that require high local ductility to achieve the predicted resistances according to the design rules of the new prEN 1993-1-8 is presented. The experimental campaign includes tensile and shear tests on mild steel coupons to calibrate the parameters used for the true stress-strain relationship, damage initiation criterion and fracture evolution, while a numerical model for the high strength steel grade S690 was selected from the literature. The FEA results were satisfactorily validated by experiments on bolted connections for which the rules of the new prEN 1993-1-8:2021 were used to predict the resistance and deformation behaviour. The deformation behaviour was predicted by applying the new analytical model to calculate the deformation at the bolt hole due to the bearing action. The resistances of the tested connections were also predicted using EN 1993-1-8:2005. It is clearly shown that the new design formulae predict the experimental results significantly better than the results obtained according to EN 1993-1-8:2005. The FEA of a bolt group in bending, representing a high web splice, provides new proof for an analytical model for the distribution of forces between the bolts in the elastic stage and at ultimate resistance. Furthermore, the new Eurocode approach for predicting the bearing deformation behaviour at the bolt hole agreed well with the experimental and numerical results.