Influence of Head Geometry on Bolted Joint Behavior

Numerical models of single-fastener bolted lap joints are developed in which the effect of the head angle and height on joint elongation are studied for three fastener sizes, three panel materials, and several panel thicknesses. Baseline 100° bolt-head angle numerical models are calibrated and validated with experimental data. These baseline models are then modified to predict the load-elongation behavior of lap joints with five different head angles and four different head heights. The numerical predictions are summarized in graphical form. The results show that the fastener head height has a much greater influence on joint-slip resistance than does the angle, with the shallower heads providing the greatest resistance to joint elongation under load.