Standard beam connections in combined shear and tension.

摘要

Investigation of the behaviour of standard shear connections subjected to combined shear and tension loading was carried out through an extensive experimental program. The program included 111 tests of five commonly used shear connections including header angle, knife angle, single angle, shear tab, and end plate connections. All specimens were subjected to an initial rotation of 0.03 radians which was maintained throughout the test along with a prescribed shear between zero and Vr, the design shear resistance. Although the primary focus was to determine tension capacity of connections in the presence of realistic levels of shear, some benchmark specimens were tested in pure shear and pure tension.; Results showed significant differences in serviceability, ductility, interaction relationships, and ultimate tension strength for the five shear connections. Quality of workmanship among fabricators varied considerably for test specimens and fabrication defects were found to influence the type of failure mode in some cases. Header angles reached ultimate tension loads as high as 576 kN but exhibited unacceptably high deformations well before failure occurred. Behaviour of end plates was similar but the magnitude of tension deformation was lower for equivalent connection parameters. Knife angle connections provided the lowest combined shear and tension resistance. Both single angle and shear tab connections showed good tension resistance in the presence of shear coupled with low tension displacements, demonstrating both serviceability and strength for this application. These two types also showed less interaction between applied shear and tension resistance than header angle connections. Connections provided ductility through yielding in bearing at bolt holes, bending of angle legs and end plates, and yielding in shear of the gross section of connection elements.; Tension and shear load vs. displacement data were acquired and plots were provided for all tests in view of the importance of ductility and serviceability considerations in design. Recommendations for the selection and design of simple connections with tension loading combined with shear load were compiled on the basis of these test results. Existing methods of determining connection resistance related to bolt shear, net section shear, and bearing resistance were used where applicable and comparison with test results has been included. In general, results indicate that interaction effects should be accounted for in the design process.; This combination of loading had not previously been investigated by others in an experimental program. The test results, photographs, load vs. displacement data, and observations of behaviour will provide unique and useful information for designers selecting an appropriate connection for shear and tension loading.