High Strength Bolts Subject to Tension and Prying

The connections were loaded so that the bolts received tension. The effects of bolt load-deformation characteristics (ASTM A325 and A490), the tee geometry and the connection detailing were considered in the investigation. A two-dimensional finite element technique was used to model the flange of the connection and a typical nonlinear bolt load deformation curve accounted for the bolt behavior. The load distribution on the flange, the stresses in the flange, the bolt load, and the bolt deformation were computed at zero applied load in increments to ultimate. Failure was either by bolt rupture or formation of a plastic hinge in the flange. The prying forces which develop as a result of flange deformation are shown to cause substantial reduction in both the ultimate load capacity and the fatigue strength for certain connections. Empirical equations are presented for the prediction of the ultimate strength of tee connections.