UBC Theses and Dissertations
Behaviour of headed stud connections for precast concrete panels under monotonic and cycled shear loading Neille, Donald Stewart
The research on headed stud connections described in this dissertation forms a part of an overall objective of predicting the behaviour of precast concrete panel buildings under earthquake loads. Existing laboratory test data and current design procedures of headed stud connections are briefly reviewed. It is postulated that shear loads are transmitted via a connection to the surrounding concrete by three distinct mechanisms: 1. friction between faceplate and concrete 2. bearing of end of faceplate on concrete 3. interaction between studs and concrete Tests on laboratory models designed to isolate individual aspects of these mechanisms confirm that all three exist. Friction forces between faceplate and concrete are small in comparison with the remaining forces acting in a connection, particularly under cycled loading. Bearing of the end of the faceplate on concrete and interaction between studs and surrounding concrete are shown to be the main contributions to the total load carried by a connection. A simple analytical model is presented for the prediction of the ultimate shear load capacity of a connection and a computer algorithm is proposed for the prediction of the load versus deflection behaviour of a connection under both monotonic and cyclic conditions. Existence of the three mechanisms whereby a connection transfers applied shear forces to the surrounding concrete contradicts the shear friction equation which is currently used in the design of connections. The analytical equations developed in the investigation indicate that the strength of a connection is directly dependent upon the strength of the surrounding concrete, as opposed to the expression for shear friction, which does not contain concrete strength as a variable.
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